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					               Field Day
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     Greenley Memorial
      Research Center




Greenley Memorial
 Research Center
GREENLEY MEMORIAL RESEARCH CENTER
ADVISORY BOARD

Hortense Greenley           Roger Hugenberg                 Dan Schmitz
Edina                       Hannibal                        Ewing

Harold Beach                Rhett Hunziker                  Jesse Schwanke
Leonard                     Knox City                       Leonard

State Rep. Rachel Bringer   Chuck Keller                    Dr. Mike Seipel
Palmyra                     Taylor                          Kirksville

Jeff Case                   Bruce Lane                      State Rep. Tom Shively
LaPlata                     Kirksville                      Shelbyville

John Cauthorn               State Rep. Rebecca McClanahan   Senator Wes Shoemyer
Mexico                      Kirksville                      Clarence

Kathy Chinn                 State Rep. Brian Munzlinger     Kenneth Suter
Clarence                    Williamstown                    Wyaconda

Jamey Cline                 Dan Niemeyer                    Dr. Paul Tracy
Columbia                    Edina                           Columbia

Ned Daggs                   Jeff Otto                       Jamie Triplett
Ewing                       Novelty                         Rutledge

Dan Devlin                  Bob Perry                       Harold Trump
Knox City                   Bowling Green                   Luray

Zac Erwin                   State Rep. Paul Quinn           Dr. Glenn Wehner
Monticello                  Monroe City                     Kirksville

Dale Hawkins                Philip Saunders                 Paul Wilson
Shelbyville                 Shelbina                        Shelbyville

Brent Hoerr                 John Schaffer                   John Wood
Palmyra                     LaGrange                        Monticello
WELCOME

We are pleased to be your host today at the Greenley Research Center. Visitors are always
welcome whether you are attending field day, a special tour, a meeting, or just passing through
the area.

We encourage you to ask questions. You are the reason this farm exists and sometimes your
questions or suggestions become an entire experiment or demonstration that benefits many
people.

Dr. Kelly Nelson, Greenley Research Agronomist, and our campus based project leaders are
continually looking at new technology and researching management systems to better meet the
changing needs of Northeast Missouri agriculture. We welcome your inputs and ideas for future
research.

We would like to thank the members of our Advisory Board for their support and guidance. They
are greatly appreciated.

We have continued our work and efforts to demonstrate biotechnology with newly approved and
soon to be approved herbicides and insect tolerant crops. We are looking at many value-added
crops and management systems to lower production cost and improve yields with the potential
for added premiums at the market place. Tile drainage at the Ross Jones was installed in July
2001 and a corn/soybean rotation has been established. The sub-irrigation water system was
installed in July 2003. The system now allows for drainage and sub-irrigation system to function
on a claypan soil that dominates most Northeast Missouri’s acreage. Our beef herd consists of a
hundred cows and used for research and demonstration. The herd continues to improve with the
efficiency of our synchronization and artificial insemination to superior sires. We practice
rotational grazing and continue to strive to reduce the input costs and produce quality beef that
today’s consumers demand.

If you are not on our mailing list or email list for flyers or meetings and would like to be, please
let us know.

The information in this field day report is a brief overview of current research and
demonstrations here at the Center and other Agriculture Experiment Station locations.

We hope you learn and enjoy your day at the Greenley Memorial Research Center.

Randall Smoot                                                                Dr. Kelly Nelson
Superintendent                                                            Research Agronomist

Jeremy Holman                          Sandy Devlin                          Clint Meinhardt
Farm Worker II                         Office Support III                   Research Specialist

Brett Craigmyle                                                             Miranda Glasgow
Summer Intern                                                                  Summer Intern
TABLE OF CONTENTS
TOPIC & AUTHOR(S)                                                                                                                PAGE(S)
    2009 Weather .............................................................................................................................1 - 3
      Soil Temperatures, Precipitation, and Weather Station Information

    Managed Drainage System for Crop Production ........................................................................4 - 6
      Kelly Nelson, Clint Meinhardt, and Randall Smoot

    MU Drainage and Subirrigation (MUDS) Research Update ....................................................7 - 19
      Kelly Nelson, Clint Meinhardt, and Randall Smoot

    Receiving Cattle – Management and Nutrition.......................................................................20 - 25
      Justin Sexten

    Forage Sampling and Analysis Interpretation.........................................................................26 - 28
       Zac Erwin

    Evaluation of the Utility and Economics of High-Input vs. Low-Input Corn
    Production Systems in Missouri ..........................................................................................29 - 35
       Kevin Bradley, Bruce Hibbard, Laura Sweets, Ray Massey, and Wayne Bailey

    Glyphosate Tank-Mixes in Roundup Ready Soybean ............................................................36 - 37
      Kevin Bradley

    Delineation of High Risk Field Areas for Variable Source N Fertilizer Applications
    to Optimize Crop N Use Efficiency .......................................................................................38 - 47
       Peter Motavalli, Kelly Nelson, Steve Anderson, and Paul Tracy

    Utility of Polymer-Coated Urea as a Fall-Applied N Fertilizer Option for
    Corn and Wheat.......................................................................................................................48 - 55
        Peter Motavalli and Kelly Nelson

    The Impact of Fertilizer Source and Tillage Systems on Nitrous Oxide Emissions...............56 - 59
      Patrick Nash, Peter Motavalli, and Kelly Nelson

    University of Missouri Extension Diagnostic Labs ....................................................................... 60
      Max Glover

    Foliar Fertilizer and Fungicide Interactions on Corn..............................................................61 - 66
       Kelly Nelson, John Shetley, Peter Motavalli, Gene Stevens, Bruce Burdick,
       and Laura Sweets

    Effect of Nitamin and Headline on Corn Grain Yield ............................................................67 - 71
       Kelly Nelson and Clint Meinhardt

    Competition of Volunteer Corn and Removal from Transgenic Corn Hybrids......................72 - 73
      Tye C. Shauck and Reid J. Smeda
TABLE OF CONTENTS (Continued)
TOPIC & AUTHOR(S)                                                                                                              PAGE(S)
    The Effect of Residual N from Corn on Wheat Production....................................................74 - 76
      Kelly Nelson and Peter Motavalli

    The Importance of Within-Field Inoculum from Corn Debris in the Management
    of Fusarium Head Blight of Wheat ................................................................................................ 77
       Laura Sweets and Gary Berstrom

    The Effect of Slow- and Fast-Release Urea Fertilizer Ratios and Timings on
    Wheat Grain Yield ..................................................................................................................78 - 83
      Kelly Nelson, Peter Motavalli, Clint Meinhardt, and Randall Smoot

    Nutrient Management in Biofuel Crop Production ............................................................... 84 - 86
      Tim Reinbott, Manjula Nathan, Kelly Nelson, and Robert Kremer

    Field Calibration of Woodruff, Mehlich and Sikora Buffer Tests for Determining
    Lime Requirement for Missouri Soils.....................................................................................87 - 91
       Manjula Nathan, Robert Kallenbach, Kelly Nelson, David Dunn, and Tim Reinbott

    2009 Missouri Variety Testing Program........................................................................................ 92
      Bill Wiebold, Howard Mason, Delbert Knerr, Richard Hasty, David Schwab,
      Jeremy Angotti, and Bill Schelp

    North Missouri Soybean Breeding..........................................................................................93 - 94
      David Sleper and Kerry Clark

    MU Extension Scouting Missouri for Soybean Rust in 2009 ........................................................ 95
     Allen Wrather

    Effects of Buffer Strip Installation on Runoff, Dissolved Organic Matter and Soil
    Organic Matter .......................................................................................................................96 - 99
       Kristen Veum, Keith Goyne, Peter Motavalli, Ranjith Udawatta, and Gene Garrett

    Greenley Research Center Publications .............................................................................100 - 102

    Greenley Endowment for Agricultural Research ...............................................................103 - 104
      Harold Beach
WEATHER STATION INFORMATION

Thanks to the Commercial Agriculture Program and the Atmospheric Science Unit the
automated weather station was installed at the Greenley Research Center in early September
1994.

Soil Temperatures
One of the unique features of the weather station is to record soil temperatures at the two inch
depth for corn, soybean, wheat residue, and bare soil. Find below a table with soil
temperature recordings at the two inch level for bare soil and corn residue starting April 1 and
ending April 30.

                         Soil Temperatures at the Two Inch Level

       DATE                             BARE SOIL                     CORN RESIDUE
       April 1                            45.7                           42.1
       April 2                            40.3                           42.0
       April 3                            47.0                           42.5
       April 4                            45.2                           44.1
       April 5                            43.6                           42.9
       April 6                            36.5                           37.5
       April 7                            44.4                           39.3
       April 8                            45.0                           42.1
       April 9                            41.5                           41.7
       April 10                           48.3                           45.2
       April 11                           47.9                           44.7
       April 12                           43.3                           43.1
       April 13                           43.4                           42.7
       April 14                           47.1                           44.3
       April 15                           52.0                           48.1
       April 16                           50.0                           48.9
       April 17                           55.8                           52.6
       April 18                           57.6                           55.2
       April 19                           52.2                           52.3
       April 20                           50.4                           49.2
       April 21                           48.0                           46.5
       April 22                           56.7                           53.0
       April 23                           55.6                           54.4
       April 24                           59.2                           57.3
       April 25                           63.6                           61.4
       April 26                           65.5                           62.9
       April 27                           59.7                           58.5
       April 28                           55.3                           54.8
       April 29                           58.9                           57.1
       April 30                           64.0                           62.0
Soil temperatures are usually coolest between 6 a.m. and 8 a.m. The highest soil
temperatures occur between 4 p.m. and 6 p.m. The average soil temperature will be
higher than those read in the morning.

Ideal soil temperatures for good corn germination should be 50 degrees F at the two inch
depth of soil measured between 8 a.m. and 9 a.m. Minimum soil temperatures for good
soybean germination should be 55 degrees F at the same depth and for grain sorghum
(milo) they should be 60 degrees F at the same depth.

                     Maximum and Minimum Air Temperatures

DATE                         MAX AIR TEMP                     MIN AIR TEMP
April 1                          55.5                             32.0
April 2                          49.9                             33.9
April 3                          56.8                             28.0
April 4                          61.7                             34.8
April 5                          50.1                             33.6
April 6                          37.7                             30.6
April 7                          50.2                             28.0
April 8                          60.4                             30.2
April 9                          55.0                             31.9
April 10                         55.1                             37.0
April 11                         57.1                             32.0
April 12                         50.7                             34.0
April 13                         42.9                             37.6
April 14                         54.8                             36.3
April 15                         64.0                             33.9
April 16                         63.2                             40.5
April 17                         71.6                             41.2
April 18                         63.5                             55.0
April 19                         58.1                             44.2
April 20                         59.7                             38.0
April 21                         61.4                             37.6
April 22                         73.8                             42.1
April 23                         75.6                             52.2
April 24                         82.3                             51.7
April 25                         78.3                             61.1
April 26                         81.7                             61.3
April 27                         64.0                             46.0
April 28                         56.6                             43.8
April 29                         64.9                             51.5
April 30                         71.3                             58.9

                           Weather information is available at
                   http://aes.missouri.edu/greenley/weather/index.stm
2009 PRECIPITATION
GREENLEY MEMORIAL RESEARCH CENTER


      APRIL                   MAY                  JUNE                   JULY

    4/2       0.08      5/1         0.07    6/2           0.98    7/3            0.18

    4/4       0.16      5/7         0.25    6/3           0.06    7/4            0.86

    4/5       0.18      5/8         0.22    6/6           0.11    7/5            0.01

    4/9       0.32     5/12         0.15    6/7           0.17    7/10           1.07

    4/10      0.92     5/13         0.83    6/8           0.08    7/12           0.12

    4/12      0.13     5/15         3.77    6/9           0.22    7/14           0.20

    4/13      0.31     5/16         0.01    6/10          1.30    7/ 21          1.46

    4/18      0.52     5/23         0.44    6/11          1.02    7/ 23          0.21

    4/19      0.11     5/25         0.67    6/15          0.23    7/25           0.10

    4/26      0.02     5/26         0.25    6/16          0.91   TOTAL           4.21

    4/27      1.14     5/30         0.04    6/19          0.18

    4/29      0.84    TOTAL         6.70    6/20          0.09

    4/30      0.05                          6/21          0.01

  TOTAL       4.78                          6/22          0.02

                                            6/23          0.22

                                            6/24          0.07

                                            6/27          0.04

                                           TOTAL          5.71




Real-Time Weather at Novelty (updated every 5 minutes) is available at:
     http://aes.missouri.edu/greenley/weather/novelty.stm
MANAGED DRAINAGE SYSTEM FOR CROP PRODUCTION
Kelly Nelson                             Clint Meinhardt
Research Agronomist                                                           Research Specialist
                                                                               Randall Smoot
                                                                                   Superintendent

Managed drainage has been utilized as a best management system to reduce NO3-N loss through
subsurface drain tiles. Regulated water flow through the winter months has reduced NO3-N
loading of streams up to 75%. Field research will be conducted on claypan and silty clay soils to
evaluate the impacts of managed drainage systems for crop and livestock production from 2009
to 2012. Enhanced efficiency fertilizers may further reduce NO3-N loss through subsurface
drainage systems that utilize managed drainage for corn production. The hypothesis of this
research is that managed drainage and enhanced efficiency fertilizer (polymer-coated urea) will
synergistically increase corn yields and reduce NO3-N loss, and managed drainage will reduce
NO3-N loss from an intensive annual forage production system. This research will 1) determine
the effects of managed drainage systems and enhanced efficiency nitrogen fertilizer (polymer-
coated urea) on corn production, nitrogen use efficiency, and nitrogen loss through the drainage
system; and 2) evaluate the effects of managed drainage on forage production, nitrogen use
efficiency, and non-point source nitrogen loss through the drainage system.

Experimental sites:
x Greenley site (claypan). Two subsurface drain tiles will be placed on 20 ft centers with a
   water level control structure installed in four of the six plots (Figure 1). Treatments will
   include drainage only, managed drainage, and a non-drained control in a factorial
   arrangement with an enhanced efficiency fertilizer, (polymer-coated urea) or non-coated
   urea. A plastic barrier will be installed between the non-drained controls, drainage only, and
   managed drainage treatments. A levee plow used to construct rice levees will be used to
   separate plots and prevent surface water movement between treatments.
x Bee Ridge site (silty clay). Subsurface drain tiles will be installed on 20 ft centers with a
   four water level control structures installed per replication (Figure 2). There will be a 40 ft
   spacing between treatments since the soil permeability is very slow. Fertilizer treatments
   will be similar to the Greenley site.
x Forage site (silt loam). Subsurface drain tiles will be installed on 60 ft centers with a non-
   treated control, managed drainage, and drainage only treatments (Figure 3). No enhanced
   efficiency fertilizer applications will be made to the experimental site since forage yields
   have not increased using this fertilizer source in Missouri (Nelson et al., 2008)

The objectives will be met to determine the effects of managed drainage systems and enhanced
efficiency fertilizers on row crop and forage production, nitrogen use efficiency, and nitrogen
loss in field plots specifically established for rigorous comparison of managed drainage systems.
Soil and water conservation systems for productivity and environmental protection are key
components of this managed drainage project. In order for rural communities to remain
competitive in a rapidly changing agricultural environment, technology that integrates current
best management practices will maintain a highly productive, safe, and efficient food supply.
Water conservation, reduced fertilizer loss, increased nutrient use efficiency, and reduced
sediment loss while improving crop production using managed drainage that is based on solid
research is a win-win situation for farmers, consumers, and the environment. It is expected that
there will be a reduction in NO3-N loading of up to 75% (Zucker and Brown, 1998;
Frankenberger et al., 2006; Drury et al., 2009), and an additive effect of the enhanced efficiency
fertilizer on reducing N loss in the crop production system and increasing corn grain yield.
Managed drainage has not been studied in livestock production systems. This research will
evaluate the impact of managed drainage on water quality and soil compaction in an annual
forage production system with management intensive grazing. This research will be utilized to
demonstrate the impact of managed drainage on improved water quality, crop and forage
production, and transfer this knowledge through field day events, field day reports, and written
and broadcast media outlets.

References:
Drury, C.F., C.S. Tan, W.D. Rynolds, T.W. Welacky, T.O. Oloya, and J.D. Gaynor. 2009.
   Managing tile drainage, subirrigation, and nitrogen fertilization to enhance crop yields and
   reduce nitrate losss. J. Environ. Qual. 38:1193–1204.
Frankenberger, J., E. Kladivko, G. Sands, D. Jaynes, N. Fausey, M. Helmers, R. Cooke, J.
   Strock, K. Nelson, and L. Brown. 2006. Drainage water management for the Midwest:
   Questions and answers about drainage water management for the Midwest. Purdue Ext., p. 8.
Nelson, K. A., P.C. Scharf, L.G. Bundy, and P. Tracy. 2008. Agricultural management of
   enhanced-efficiency fertilizers in the north-central United States. Online. Crop Management
   doi:10.1094/CM–2008–0730–03–RV.
Zucker, L.A. and L.C. Brown (Eds.). 1998. Agriculture drainage: water quality impacts and
   subsurface drainage studies in the Midwest. Ohio State University Extension Bulletin 871.
   The Ohio State University. pp. 40.


                                                           Main


                    Barrier between plots
                    with a surface levee

 Replication 2


                                                                  Sub
                                       PCU                        mains
                 Managed drainage      NCU
                                       PCU
 Replication 1       Drainage only     NCU
                     Non drained       PCU
                                       NCU


                                                    Water level control
                                                       structures



Figure 1. Managed drainage (dotted lateral tile lines), drainage only (solid lateral tile lines), and
non-treated control (white boxes) main plots at the Greenley site. Laterals will be installed on 20
ft centers. Sub-plots include polymer- (PCU) and non-coated urea (NCU). Barriers and surface
levees will be placed around all treatments. Individual water-level control structures will be
utilized for each subsurface drainage treatment.
                                            Managed drainage                           Drainage only


                                                                                                              Non drained




                                                                    NCU




                                                                                                        PCU
                                                                                                  NCU
                                                              PCU
                                            NCU




                                                                                            PCU
                                                                                      NCU
                                      PCU



                                                        NCU




                                                                                NCU
                                                  PCU




                                                                          PCU
                                                                                                              Main

                Water level control
                   structures                Replication 1                  Replication 2

Figure 2. Managed drainage (dotted lateral tile lines), drainage only (solid lateral tile lines), and
non-treated control main plots at the Bee Ridge site. Laterals will be installed on 20 ft centers
with 40 ft between treatments. Sub-plots include polymer- (PCU) and non-coated urea (NCU).
Individual water-level control structures will be utilized for each subsurface drainage treatment.




                                       Sub main
                                                                      Water level control
                                                                         structures

       Replication 1


                                                                                       Main




                                                                                                   Replication 2




Figure 3. Managed drainage (dotted lateral tile lines), drainage only (solid lateral tile lines), and
non-treated control treatments at the forage site. Laterals will be installed on 60 ft centers.
Individual water-level control structures will be utilized for each subsurface drainage treatment.
MU DRAINAGE AND SUBIRRIGATION (MUDS) RESEARCH UPDATE
Kelly A. Nelson                        Clinton G. Meinhardt
Research Agronomist                                                             Research Specialist
                                                                            Randall L. Smoot
                                                                                   Superintendent
Background:
Economic situations have caused several Missouri farmers to re-evaluate production systems that
maximize yield and maintain environmental sustainability. Agricultural drainage is not a new
concept; however, utilizing drainage as part of an integrated water management system (IWMS)
is a relatively new concept that has been shown to improve water quality and sustain agricultural
viability. Subsurface drainage water from agricultural lands contributes to the quantity and
quality of water in receiving streams when properly implemented water management systems are
adopted.

Upland, flat claypan soils commonly have a seasonal perched water table from November to
May, which is caused by an impermeable underlying clay layer that restricts internal drainage.
Research in other states has reported increased crop production using IWMS’s that incorporate
subsurface drainage and subirrigation. The MUDS research program was initiated to determine
the suitability of claypan soils for drainage and a drainage/subirrigation (DSI) water-table
management system, and to evaluate the effect of the systems on corn and soybean grain yield at
different drain tile spacings compared to non-drained claypan soil.

Methods:
Subsurface drainage and DSI water-table management systems were installed in July, 2001.
This research was arranged as a split-plot design with two main plots (drainage and
drainage/subirrigation systems) and a factorial arrangement of sub-plots including a non-drained
control and three drain tile spacings (20, 30, and 40 ft) and two crops (corn and soybean) with
four replications. The corn and soybean plot size was 60 to 80 by 150 ft depending on the drain
tile spacing. Soil was a Putnam silt loam with 10%, 75%, and 15% sand, silt, and clay,
respectively. Field information and rainfall data are summarized in Tables 1 and 2, respectively.
A delayed planting control was included in the design. Non-drained checks usually delay
planting of drained treatments in research projects; therefore, two non-drained controls were
included in the design to reduce the confounding effect of planting date on results. One is
planted at the time the drained treatments are planted regardless of the soil conditions. The other
is delayed based on typical soil conditions that are suitable for planting.

The DSI system was shifted into controlled drainage mode in June, 2002 and a temporary water
supply system was implemented for subirrigation during the growing season. The water supply
did not provide enough volume to substantially raise the water table; however, baseline data
were established on the impact of subirrigation on production in 2002. These results have been
similar to subsequent years and were included in the results. Soybean plots equipped with a
water-table management system were not subirrigated in 2002. Subirrigation of soybean was
initiated in 2003 and corn was subirrigated from 2004 to the present. Table 1 summarizes the
subirrigation timing schedule while Table 2 summarizes the amount of water supplied through
the subirrigation system on the 20 ft lateral spacing from 2004 to 2007. Water meters recorded
the quantity of water supplied through the subirrigation system. This was converted to inch
equivalents of rainfall.

Additional research was initiated in 2004 and 2005 to evaluate the use of slow-release nitrogen
fertilizer (ESN, Agrium, Alberta, Canada) applied to corn to control nitrogen loss when there
were differences in soil moisture conditions and drainage. Since there was no delay in early
planted corn in 2002 and 2003, an overhead irrigation system was installed to replace this
treatment. Corn was irrigated according to the Woodruff irrigation scheduling chart. The
amount of water applied with the overhead irrigation system was reported in Table 2. Sub-plots
included coated (ESN) and non-coated urea at 0, 125, and 250 lb N/a. Crop performance has
been evaluated above and between drain tiles over the past seven years; however, data was not
presented in this report.

Corn research in 2006 and 2007 compared the relative corn growth response and environmental
N losses after application of different N fertilizer sources under a range of soil moisture
conditions imposed by drainage and irrigation, and examined the spatial differences in soil N
transformations and N losses during the growing season between drainage and subirrigation tile
lines. Preplant injected anhydrous ammonia, urea ammonium nitrate, urea, or polymer coated
urea applied at 150 lbs N/acre were incorporated following application.

The number of soybean cultivars evaluated were expanded to five in 2007 and 2008, while corn
hybrid response was the primary focus in 2008 and will be repeated in 2009.

Results:
2002. Rainfall during the growing season was sufficient in some areas in Northeast Missouri and
insufficient in others. Corn planting date was not delayed by wet conditions; however, the crop
experienced excessive rainfall from Apr. 16 to May 13 (Table 2) and cool temperatures (data not
presented). Rainfall was scattered and a total of 3.4 inches of rain was recorded from June 24 to
August 24.

Corn grain yield for the non-treated control was 62 to 63 bu/acre (Table 3). Drainage only (DO)
treatments increased corn grain yield 10 to 20 bu/acre depending on the drain tile spacing. The
drainage/subirrigation treatment (DSI) with a 20 ft lateral spacing increased grain yield two fold
compared to the non-drained control and was 10 bu/a greater than the DSI treatment with a 30 ft
lateral spacing. Even though grain yield was doubled with the DSI system, the potential for the
system was probably underestimated due to an inadequate water supply. Corn grain yield above
the drain tile with subirrigation ranged from 150 to 165 bu/a depending on the treatment (data
not presented).

Soybean was planted three days earlier in the subsurface drained compared to the non-drained,
delayed planting control (Table 1). Soybean grain yield was 8 to 10 bu/a greater with subsurface
drainage when compared to the non-drained and non-drained delayed planting treatments (Table
4).

2003. Rainfall was adequate until mid-August. Early planted corn was not delayed by wet
conditions; however, the corn crop experienced excessive rainfall from mid-Apr. to mid-May
(Table 2) and cool temperatures (data not presented). Rainfall was scattered and a total of 0.1 in.
of rain was recorded from August 3 to August 25 with above average temperatures (data not
presented).

Corn grain yield for the non-drained controls was 99 to 109 bu/acre in 2003 (Table 3) while
drainage only increased corn grain yield 22 to 37 bu/acre depending on the drain tile spacing.

Soybean was planted two days earlier in subsurface drained treatments when compared with the
non-drained control (Table 1). Soybean grain yield was 6 to 8 bu/a greater with subsurface
drainage than the non-drained and non-drained delayed planting treatments (Table 4). Soybean
grain yield was similar in the drained and subirrigated treatments. Late rains probably helped
increase seed fill and test weight. An earlier subirrigation timing may be necessary to maximize
soybean grain yields.

2004. In general, dryland corn and soybean grain yields were above average in Northeast
Missouri. Rainfall was consistent throughout the spring and summer; however, excessive
rainfall in the fall hindered harvest (Table 2). Harvesting during these conditions probably
contributed to increased compaction. An additional 5.6 inches of water was recommended and
applied according to the Woodruff chart during the season. However, only 0.33 inches of water
were applied through the subirrigation system on the 20 ft drain tile spacing.

Drainage only increased corn grain yield up from 20 to 49 bu/acre depending on the N treatment,
N rate, and drain tile spacing. All 20 ft drain tile spacings increased grain yield regardless of N
rate or source when compared with the non-treated control. Corn grain yield was increased up to
36 bu/acre with DSI depending on the N source, N rate, and drain tile spacing. Drainage only or
DSI increased grain yield up from 19 to 49 bu/acre when compared to overhead irrigation alone.
Differences in corn grain yield response were probably related to denitrification differences due
to N source and soil moisture differences among treatments.

Soybean planting date was delayed 17 days in the non-drained control compared to drained
treatments due to wet soil conditions (Table 1). Soybean planted in the non-drained control at
the same time drained treatments were planted had grain yields 12 bu/a greater than the delayed
planting control (Table 3). Soybean grain yield was 12 to 27 bu/a greater with DO and DSI
regardless of drain tile spacing when compared to the non-drained controls.

2005. Rainfall was below normal with a total of 11.6 inches throughout the growing season
(Table 2). Less than 4 inches of rainfall was recorded from mid-June to early September.
Variability between drainage tiles for the DSI treatment was evident in corn and soybean (visual
observation). Twospotted spider mites (Tetranychus urticae) were widespread in non-irrigated
treatments during the first week of August (Figure 3). The entire plot area was sprayed to
minimize a possible confounding effect of insect feeding on soybean grain yield. A dry fall
allowed for an efficient harvest and optimal weather for fall tillage.

The non-treated control corn grain yield was 28 to 40 bu/a (Table 3). Low rainfall, high air
temperature, and wind during pollination of corn helped reduced grain yields (data not
presented). Drainage only increased corn grain yield 1.7 to 2.8 fold when compared with the
non-drained control. DSI increased grain yield from 3 to 5 times greater than the non-drained
control. Finally, grain yield with overhead irrigation was 6 to 9 times greater than the non-
drained control. The degree of impact of water management systems on corn grain yield was
affected by N rate and source. Drought stress differences above and between the drainage tiles
for the DSI system were evident and grain yields were quantified above and between the
drainage tiles. Corn grain yield above the drain tile with subirrigation ranged from 160 to 190
bu/a depending on the drain tile spacing (data not presented).

There was no delay in soybean planting date due to wet soil conditions. Soybean yield increased
7 bu/a with drainage only on a 20 ft spacing compared with the non-drained control (Table 4).
DSI increased grain yield 9 to 16 bu/a depending on the drain tile spacing. Soybean above the
drain tiles in the drainage/subirrigation water management treatment matured earlier and had
complete leaf senescence before soybean between the drain tiles and non-drained soybean.

2006. Precipitation following planting was limited, but sufficient for adequate germination and
early growth (Table 2). Irrigation was needed in late June until the first week of August and
again in late August. Overhead irrigation required over six times more water than subirrigation
throughout the season. Another dry fall allowed timely harvest and tillage operations.

The corn hybrid was switched to ‘DK C61-68’ (Table 1). Dry conditions following pollination
reduced grain yields of non-irrigated treatments. All of the water table management treatments
responded to N applications regardless of N source in 2006 (Table 3). The non-drained control
and drainage only treatments had similar grain yields which was probably due to a relatively dry
spring. DSI on 20 ft lateral spacings increased yield 41 to 72 bu/acre when compared to the non-
drained control with similar N sources. Subirrigated corn with ESN had grain yields similar to
overhead irrigation. Crop response to the water-table management system was ranked overhead
irrigation > DSI > drainage only = non-drained.

Soybean planting date was delayed 4 days for the non-drained control when compared with
drained treatments (Table 1). Drainage only or DSI increased soybean yield 3 to 5 bu/acre when
compared to the non-drained delayed planting control (Table 4). No differences in yield among
drain tiles spacings were observed.

2007. Widespread spring rainfall delayed corn planting 5 days in the non-drained delayed
planting control. Visual differences in soil surface drying were obvious (Figure 2). Irrigation
was required in late June to mid-September. Supplemental water totaled 7.74 and 4.96 inches in
the overhead and subirrigation systems, respectively (Table 2). Wet conditions early in the
season caused poor rooting depth and drainage only treatments had grain yields that were 19 to
48 bu/acre greater than non-drained soil (Table 3). DSI increased grain yield 42 to 64 bu/acre
when compared to the non-drained or non-drained delayed planting control. Overhead irrigation
increased yield 24 to 55 bu/a greater than DSI. Differences in drain tile spacing were
undetectable in 2007. Corn response to water management was overhead irrigation > DSI >
drainage only > non-drained.

High yielding soybean cultivars were included in the experimental design in 2007. Soybean
planting date was late and soil was moist in all treatments. Soybean response to drainage was
ranked DSI > DO > non-drained (Table 4). Drainage only increased yield 7 to 10 bu/acre greater
than the non-drained soil, while DSI increased yield 20 bu/a over the non-drained control.
Soybean cultivar yield response differences were detected for DSI (Figure 1), but limited
differences were observed among cultivars for the non-drained control, drainage only on a 20 ft
spacing, and drainage only on a 40 ft spacing. There was a 13 to 20 bu/acre increase in average
yield of Kruger 382, Asgrow 3602, and Morsoy 3636 on a 20 and 40 ft drain tile spacing, while
average yield increased 8 to 13 bu/acre with Pioneer 93-M96 or NK S37-N4 on either drain tile
spacing. Grain yield response differences to DSI were primarily related to the impact on yield
above and 10 to 20 ft from the drain tile.

2008. Rainfall was extensive and intensive in 2008 (Table 2). Supplemental irrigation was
required according to the Woodruff scheduling chart. However, rainfall generally followed
irrigation events; therefore, supplemental irrigation was not beneficial in 2008. Corn hybrids
were expanded to include Kruger 2114, LG 2642, Asgrow 785, DeKalb C61-73, and DeKalb
C63-42. There was no interaction between water management system and hybrid; therefore,
results were combined over hybrid (Table 3). Drainage at 20 or 40 ft spacings increased yield 21
and 25 bu/acre, respectively, when compared to the non-drained control. Corn response to water
management systems was ranked drainage only > overhead irrigation = DSI > non-drained.

High yield soybean cultivars were included in the experimental design similar to 2007 (Table 1).
Soybean planting date was extremely late due to wet conditions throughout the spring (Table 2).
Data were averaged over cultivar since there was no interaction between cultivar and water
management system (Table 4). Soybean response to water management systems was ranked DO
= DSI > the non-drained control. Drainage only increased grain yield 8 to 11 bu/acre when
compared to non-drained soil. No difference between drain tile spacing was observed in 2008.

Summary:
•   Drainage only increased average corn grain yields up to 15% while DSI has increased
    average yields up to 45% when compared with non-drained, non-irrigated soil (Table 3).

•      Overhead irrigation increased grain yield 25% compared to subirrigated corn with 20 ft
       laterals when averaged over all N treatments from 2004 to 2008 (Table 3). However,
       applied water was on average 4 times greater for overhead irrigated corn compared with
       subirrigated corn on a 20 ft drain tile spacing from 2004 to 2007 (Table 2).

•      Soybean planting date was delayed an average of 3 days for the non-drained control when
       compared with drained soils from 2002 to 2008 (Table 1).

•      Soybean grain yield with DO has averaged up to 23% greater than the non-drained
       delayed planting controls (Table 4). Similarly, DSI had soybean grain yields up to 27%
       greater than the non-drained delayed planting controls.


Acknowledgments:
      The authors would like to thank the Missouri Soybean Merchandising Council; Missouri
Corn Growers Association; Landmark Irrigation, Inc., Taylor, MO; Agri Drain Corp., Adair, IA;
Hawkeye Tile Inc., Taylor, MO; Liebrecht Manufacturing, Continental, OH; Timewell Tile,
Timewell, IL; IMI Equipment, Kahoka, MO; BASF; Syngenta; Monsanto; Pioneer Hi-Bred; and
Kruger Seeds for their support. In addition, a special thanks is extended to Matthew Jones, Dana
Harder, Keith Lay, Chris Bliefert, and Ben Bradley for their technical assistance.

Available at: http://aes.missouri.edu/greenley/research/muds.stm
               Table 1. Field information and selected management practices for corn and soybean from 2002 to 2008.
                     2002                         2003                    2004                      2005                    2006                           2007                    2008
Corn
Tillage              Nov. 12, 2001 chisel         No-till                 Nov. 17, 2003 chisel      Mar. 13, 2005 disk-     Nov. 10, 2005 chisel plowed;   Nov. 22, 2006 chisel    May 2, 2008 Tilloll,
                     plowed; Apr. 5, 2002                                 plowed; Mar. 24, 2004     harrowed; Apr. 8,       Mar. 2, 2006 disk-harrowed     plowed, May 1 and
                     field cultivated                                     and Apr. 15, 2004 field   2005 field cultivated   and Apr. 11, 2006 field        May 2, 2007 field
                                                                          cultivated                                        cultivated                     cultivated
Row spacing (in.)    30                           30                      30                        30                      30                             30                      30
Planting date        Apr. 17                      Apr. 12                 Apr. 15                   Apr. 8                  Apr. 11                        May 13                  May 5
Delayed planting     None                         None                    None                      None                    None                           May 18                  None
date
Hybrid(s)            ‘Pioneer 33P67’              ‘Pioneer 33P67’         ‘Pioneer 33P67’           ‘Pioneer 33P67’         ‘DeKalb C61-68’                ‘DeKalb C61-68’         ‘Kruger 2114, LG
                                                                                                                                                                                   2642, Asgrow 785,
                                                                                                                                                                                   DeKalb C61-73,
                                                                                                                                                                                   DeKalb C63-42’
Seeding rate
(seeds/a)            30,000                       31,000                  32,000                    34,000                  33,000                         33,000                  32,000
Controlled
drainage date(s)     June 15                      June 10                 July 1                    June 1                  June 15                        June 15                 July 17
Subirrigation date   July 19-Aug. 30a             ______b
                                                                          July 20-Aug. 25           June 1-Sep. 6           June 23-Aug. 30                June 28-Sep. 14         July 17-Sept. 10
Drainage mode        Sep. 1                       Sep. 15                 Sep. 25                   Sep. 6                  Aug. 30                        Sep. 14                 July 25-Aug.4, Sep.
                                                                                                                                                                                   10
Harvest date         Sep. 15                      Sep. 30                 Nov. 12                   Sep. 20                 Sep. 8                         Oct. 6                  Nov. 4
Fertility            Fall, 2001                   Fall, 2002              Mar. 24, 2004             Mar. 17, 2005           Apr. 11, 2006                  May 1, 2007             May 1, 2007
                     17-80-100                    17-80-100               17-80-140-3 + 5 lb/a Zn   12-60-120               150-0-0 urea, ESN, urea        22-104-300              180-0-0 anhydrous
                     Apr. 17, 2002                Apr. 3, 2003            Apr. 15, 2004             Apr. 8, 2005            ammonium nitrate, or           150-0-0 urea, ESN,      ammonia,
                     200-0-0 Ammonium             250-0-0 Anhydrous       125-0-0 urea or ESN       125-0-0 urea or ESN     anhydrous ammonia              urea ammonium           Nov. 26, 2008
                     nitrate                      ammonia                 250-0-0 urea or ESN       250-0-0 urea or ESN                                    nitrate, or anhydrous   30-80-160
                                                                                                                                                           ammonia
Weed
management
  Timing, date       Preemergence, Apr. 19        Preemergence, Apr.      Early postemergence,      Early postemergence,    Early postemergence,           Early POST, May 19      Early POST, May
                                                  12                      Apr. 27                   May 6                   May 15                                                 29
   Herbicide         Bicep II Magnum +            Guardsman MAX +         Lumax                     Lumax + NIS             Lumax + NIS                    Roundup                 Roundup
                     Princep + 2,4-D ester        Princep +                                                                                                WeatherMAX + AMS PowerMAX +
                                                  Touchdown + Quest                                                                                                                Lumax + AMS
   Rates             2.6 qt/a + 1 qt/a + ½ pt/a   2 qt/a + 1 qt/a + 1     3 qt/a                    3 qt/a + 0.25% v/v      3 qt/a + 0.25% v/v             22 oz/a + 17 lb/100 gal 22 oz/a + 3 qt/a + 17
                                                  pt/a + ½ pt/a                                                                                                                    lb/100 gal
   Timing, date                                   POST, June 5                                                                                             POST, June 11
   Herbicide                                      Callisto + atrazine +                                                                                    Bicep II Magnum +
                                                  COC + AMS                                                                                                Roundup
                                                                                                                                                           OriginalMAX + AMS
   Rates                                          3 oz/a + 8 oz + 1%                                                                                       2.5 qt/a + 22 oz/a + 17
                                                  v/v + 2 lb/a                                                                                             lb/100 gal
Insect            Kernel guard              Gaucho seed         Poncho 250 seed           Poncho 250 seed          Poncho 250 seed treatment;   Poncho 250 seed        Poncho 250 seed
management                                  treatment           treatment                 treatment; Warrior 3.8   Warrior 3.8 oz/a, May 15     treatment, Warrior 2.2 treatment
                                                                                          oz/a, May 6                                           oz/a, May 11; Perm up
                                                                                                                                                6
Disease                                                                                                                                         Headline 6 oz/a, July
management                                                                                                                                      17
pHs               6.5 + 0.5                 6.8 + 0.3           6.7 + 0.1                 6.9 + 0.2                6.6 + 0.1                    6.9 + 0.1
SOM (%)           2.6 + 0.2                 1.9 + 0.1           2.1 + 0.1                 2.7 + 0.1                1.8 + 0.1                    1.9 + 0.1

Soybean
Tillage           November 12, 2001         No-till             No-till                   No-till                  No-till                      No-till                No-till
                  chisel plowed
                  Apr. 5, 2002 field
                  cultivated
Row spacing (in.) 7.5                       7.5                 7.5                       7.5                      7.5                          15                     15
Planting date     May 30                    May 27              May 21                    May 2                    May 11                       May 23                 June 16
Delayed planting
date              June 2                    May 29           June 4                       May 2                    May 15                       May 23                 June 16
Cultivar          Pioneer 93B85             Kruger 401RR/SCN Kruger 380RR/SCN             Kruger 380RR/SCN         Kruger 380RR/SCN             Asgrow 3602, Kruger    Asgrow 3602,
                                                                                                                                                382, Pioneer 93M96,    Kruger 382, Pioneer
                                                                                                                                                NK S37-N4,             93M96, NK S37-
                                                                                                                                                Morsoy3636             N4, Morsoy3636
Seeding rate
(seeds/a)          180,000                  200,000             200,000                   200,000                  200,000                      200,000                200,000
Controlled
drainage date(s)   June 20                  June 25             July 1                    June 1                   June 15                      June 15                July 17
Subirrigation date ______b                  Aug. 21             July 20-Aug. 25           June 1-Sep. 6            June 23-Sep. 30              June 28-Oct. 1         July17-Sep. 15
Drainage mode      Oct. 4                   Sep. 15             Sep. 25                   Sep. 15                  Sep. 19                      Oct. 1                 July 25-Aug. 4, Sep.
                                                                                                                                                                       15
Harvest date      Oct. 9                    Oct. 8              Oct. 17                   Oct. 10                  Oct. 3                       Oct. 30                Oct. 30
Fertility         Fall, 2001                Fall, 2002          Mar. 24, 2004             Mar. 17, 2005            NA                           May 1, 2007            Nov. 26, 2008
                  17-80-100                 17-80-100           17-80-140-3 & 5 lb/a      12-60-120                                             22-104-300             30-80-160
                                                                Zn
Weed
management
  Timing, date    Burndown, June 7          Burndown, June 20   Burndown, May 3    Early Postemergence,            Burndown, May 15             Burndown, May 18       Burndown, May 28
                                                                                   June 1
  Herbicide       Roundup UltraMAX +        Roundup             Roundup WeatherMAX Roundup                         Roundup WeatherMAX +         Roundup                Roundup
                  AMS                       WeatherMAX +        + AMS              WeatherMAX + AMS                AMS                          WeatherMAX + AMS       PowerMAX + Dual
                                            AMS                                                                                                                        II Magnum
  Rates           26 oz/a + 17 lb/100 gal   22 oz/a + 17 lb/100 22 oz/a + 17 lb/100 gal   22 oz/a + 17 lb/100 gal 22 oz/a + 17 lb/100 gal       22 oz/a + 17 lb/100gal 32 oz/a + 1.66 pt/a
                                            gal
  Timing, date    Postemergence, July 5     Postemergence, July Postemergence, July 26    Postemergnce, July 11 POST, June 27                   EPOST, June 11         POST, July 17
                                            9                                                                                                   LPOST, July 17         LPOST, Aug. 26
  Herbicide       Roundup UltraMAX +        Roundup               Roundup WeatherMAX Roundup                        Roundup WeatherMAX +           Roundup                 POST: Roundup
                  AMS                       WeatherMAX +          + AMS + DriftGuard + WeatherMAX + AMS             AMS                            OriginalMAX             PowerMAX + AMS
                                            AMS + DriftGuard      Headline             + DriftGuard +                                                                      + FirstRate + NIS,
                                                                                       Quadris                                                                             LPOST: Roundup
                                                                                                                                                                           PowerMAX
  Rates           26 oz/a + 17 lb/100 gal   22 oz/a + 17 lb/100   22 oz/a + 17 lb/100 gal   22 oz/a + 17 lb/100 gal 22 oz/a + 17 lb/100 gal        22 oz/a + 17 lb/100 gal 32 oz/a + 17 lb/100
                                            gal + 2 oz/100 gal    + 2 oz/100 gal + 6 oz/a   + 2 oz/100 gal + 6 oz/a                                AMS                     gal + 0.3 oz/a, 22
                                                                                                                                                                           oz/a
Insect            None                      None                  None                      Warrior at 2.5 oz/a,    Warrior at 2.6 oz/a, June 27   Warrior at 2.2 oz/a,    Warrior at 2 oz/a,
management                                                                                  July 11                                                June 11; Permup 6       Aug., 26
                                                                                            Lorsban at 1 pt/a, Aug.                                oz/a, July 17
                                                                                            9
Disease                                                                                                             Headline 6 oz/a, June 27       Headline 7 oz/a, July   Quadris 6 oz/a, Aug.
management                                                                                                                                         17                      26
pHs               6.5 + 0.5                 6.7 + 0.2             6.7 + 0.2                 6.8 + 0.1               6.5 + 0.1                      7.0 + 0.1
SOM (%)           2.6 + 0.2                 2.0 + 0.1             2.2 + 0.2                 2.7 + 0.2               2.0 + 0.1                      1.8 + 0.1
             a
              The water supply provided approximately 1500 gallon/replication/day. This did not provide enough volume to substantially raise the water table;
             however, preliminary data was established on the impact of subirrigation on corn production in 2002.
             b
               Treatments were not included.
Table 2. MUDS annual rainfall, overhead irrigation, and subirrigation totals for 2002 to 2008.

                           2002    2003            2004                  2005                      2006                   2007               2008
                                 a                              b
    Time period           Precip. Precip. Precip. OhIrr. SubIrr. Precip. OhIrr. SubIrr.    Precip. OhIrr. SubIrr. Precip. OhIrr. SubIrr. Precip. OhIrr.
                                                                             Inches
    January                0.65    0.29    1.14     0      0      2.74     0        0       2.11     0        0    0.83     0       0     0.78
    February               2.08    0.88    0.38     0      0      2.15     0        0       0.09     0        0    2.68     0       0     3.90
    Mar.                   0.96    1.27    1.94     0      0      1.21     0        0       2.83     0        0    4.87     0       0     3.08
    Apr 1 to Apr 15        1.25    1.73    0.48     0      0      1.17     0        0       0.69     0        0    2.19     0       0     2.47
    Apr 16 to Apr 29       5.01    3.65    1.81     0      0      0.71     0        0       0.06     0        0    1.98     0       0     2.11
    Apr 30 to May 13       7.93    3.67    0.85     0      0      1.45     0        0       2.20     0        0    2.68     0       0     2.43
    May 14 to May 27       2.01    0.72    1.81     0      0      0.36     0        0         0      0        0    0.20     0       0     1.19
    May 28 to June 10      1.07    2.38    2.92     0      0      2.85    0.6       0       2.22     0        0    1.90     0       0     3.31
    June 11 to June 24     3.59    0.06    0.91     0      0      0.70    1.1     0.23      1.64     0        0    0.60     0       0     1.94
    June 25 to July 8      0.27    1.63    1.42     0      0      0.12    2.4     0.17      0.97     3      0.12   0.83    1.20   0.97    6.35
    July 9 to July 22      0.79    2.00    0.59    0.6    0.25    0.12    2.3     0.15      1.23     1      0.01   0.60    0.60   1.26    1.32    0.51
    July 23 to Aug 5       1.17    1.76    2.88    3.9    0.06    1.80    3.3     0.65      0.56    2.27    0.25   0.72    2.47   0.69    7.23
    Aug 6 to Aug 19        1.16    0.13    0.48    1.1    0.01    0.83    2.2     0.18      3.85     0      0.66   1.72    1.77   0.61    0.87    2.94
    Aug 20 to Sep. 2       2.11    5.04    7.56     0     0.01    0.00     0      0.03      1.42    1.30    0.16   2.05    0.84   1.20    3.13    0.80
    Sep. 3 to Sep. 16      0.11    3.04    0.42     0     0.01    1.03     0        0       0.38     0        0      0     0.86   0.23    8.77
    Sep. 17 to Sep. 30     0.81    3.08    0.23     0      0      0.47     0        0       0.28     0        0      0      0       0      0.5
    Total irrigation                               5.6    0.33           11.9 1.41                  7.57    1.20           7.74   4.96            4.25
a
    Abbreviations: OhIrr., Overhead Irrigation; Precip. Precipitation; and SubIrr., Subirrigation.
b
    Subirrigation water use was reported for the 20 ft drainage/subirrigated drain tile spacing for corn.
Table 3. Corn grain yield for the non-drained, drainage only, and drainage/subirrigation water-table management treatments at 20, 30, and 40 ft lateral spacings
from 2002 to 2008.a
                                                                      Non-drained              Non-drained                Drainage only        Drainage/subirrigation
                Year       N source    N rate     Non-drained       delayed planting        overhead irrigated            20 ft        40 ft     20 ft       40 ft      LSD (p<0.05)
                                                                ____________________________________________          _______________________________
                                       lbs/acre                                                                bu/a
                               b                                                                   _____c
                2002 AN                200            63                   62                                              81           79       120d        104d           12
                                                                                                    _____                                        _____       _____
                2003 AA                250            99                  109                                             131          136                                  20
                                                                          _____
                2004       Non-treated 0              97                                             83                   129          115       115          63            26
                                                                          _____
                           Urea        125           168                                            197                   208          207       198          194           27
                                                                          _____
                                       250           182                                            197                   215          197       216          200           13
                                   e                                      _____
                           ESN         125           181                                            197                   211          214       217          205           19
                                                                          _____
                                       250           201                                            189                   221          209       218          212           19
                                                                          _____
                2005       Non-treated 0              39                                             98                    66           74        72          59            23
                                                                          _____
                           Urea        125            38                                            240                    74           66       113          115           25
                                                                          _____
                                       250            28                                            263                    77           61       147          126           32
                                                                          _____
                           ESN         125            40                                            236                    66           71       125          117           30
                                                                          _____
                                       250            31                                            263                    52           59       139          132           26
                                                                          _____
                2006       Non-treated 0              85                                            114                    93           88       102          91            25
                                                                          _____
                           AA          150           138                                            240                   136          137       179          168           37
                                                                          _____
                           ESN         150           131                                            241                   139          143       203          182           40
                                                                          _____
                           Urea        150           129                                            237                   142          135       198          184           39
                                                                          _____
                           UAN         150           123                                            227                   142          137       175          171           35
                2007       Non-treated 0              69                   73                       107                   110          105       112          93            25
                           AA          150           112                  113                       216                   144          151       164          163           21
                           ESN         150           116                  110                       220                   136          152       172          167           28
                           Urea        150           107                  104                       201                   143          141       168          160           20
                           UAN         150           102                   98                       176                   136          143       152          144           18
                       f
                2008 AA                    180       166                                            174                   187          191       172          186           19
                           g
                  Average                              118                                   217           136     139       171         164
a
  Comparisons within rows are valid.
b
  Abbreviations: AA, anhydrous ammonia; AN, ammonium nitrate; and UAN, 32% urea ammonium nitrate.
c
  Treatments were not included.
d
  The water supply provided approximately 1500 gallon/replication/day. This did not provide enough volume to substantially raise the water table; however, baseline data was
established on the impact of subirrigation on corn production in 2002.
e
  Polymer coated urea (Agrium, Calgary, Alberta, Canada).
f
 Grain yield was averaged over hybrid (Kruger 2114 RR/YGCB, LG 2642BtRR, Asgrow 785 VT3, DKC 61-73, and DKC 63-42.
g
  Calculated as the average yield for ESN at 250 lb/a in 2004 and 2005, and ESN at 150 lb/a in 2006 and 2007.
Table 4. Soybean grain yield for non-drained, drainage only, and drainage/subirrigation water-table
management treatments at 20, 30, and 40 ft lateral spacings from 2002 to 2008.
Water-table management                 2002     2003 2004         2005       2006     2007a 2008b Averagec
Non-drained                            36       40       57       38         63       41       37       46
                               d
Non-drained delayed planting           36       42       45       38         61       40       35       44
Drainage only
    20 ft lateral spacing              45       48       71       45         66       50       45       54
                                                                                      ______   ______
    30 ft lateral spacing              43       47       70       39         65
    40 ft lateral spacing              46       48       72       41         66       48       46       54
Drainage/subirrigation
                                       ______e
    20 ft lateral spacing                       46       72       54         65       61       39       56
                                       ______                                         ______   ______
    30 ft lateral spacing                       48       69       47         64
                                       ______
    40 ft lateral spacing                       47       69       51         66       60       40       56
                                       ___
LSD (p<0.05)                               3 __ __ 3 __ __ 3 __ __ 5 __      __
                                                                                3 __ __ 6 __ __ 7 __
a
  Soybean cultivar was Kruger 382.
b
  Soybean yield was averaged over Kruger 382, Pioneer 93M96, NK S37-N4, Asgrow 3602, and Morsoy
3636N.
c
  Calculated as the average yield for 2003-2008.
d
  The planting date was delayed 3, 2, 14, 0, 4, 0, and 0 days after the drainage only and drainage/subirrigation
treatments in 2002, 2003, 2004, 2005, 2006, 2007 and 2008, respectively.
e
  Treatments were not included.
Figure 1. Soybean cultivar response to drainage (A, B), subirrigation (C, D), and no drainage (E) in 2007.
Drain tile spacing was represented as feet from the drain tile. The average yield for drain tile spacings was
reported. The least significant difference (LSD at P=0.05) was 6.
RECEIVING CATTLE – MANAGEMENT AND NUTRITION
Justin Sexten
State Extension Specialist – Beef Nutrition

When cattle arrive at a new facility such as a feedlot, backgrounding lot or stocker operation the
first 28 days after arrival are referred to as the receiving period. Length of receiving is
dependent on cattle weight or age, cattle source, previous and future feeding programs, health
risk, and transport length.

Information regarding receiving is commonly discussed relative to cattle moving from one
operation to another. Cow-calf producers retaining ownership beyond weaning will receive
weaned calves at the ranch immediately following weaning. Developing of a solid receiving
program at each production stage will benefit cattle as they are transitioned from forage to
concentrate diets.

The first 28 days following cattle arrival or weaning represent the greatest management
challenge of the entire feeding period due to performance, illness and death loss uncertainties,
despite pre-shipping management practices (Preston, 2007). The primary management and
nutritional challenge associated with receiving cattle is low dry matter intake (DMI). Table 1.
illustrates ranges in DMI associated with newly received calves. In addition, sick cattle are
slower to start eating and consume less feed than healthy calves (Hutcheson and Cole, 1986).
Getting cattle to consume 2% of body weight in dry matter is reported as the first management
and nutritional requirement of receiving cattle (Preston, 2007).

                     Table 1. Dry matter intake of newly received calves
                                                 Dry matter intake
                      Day of Receiving
                                                 % of body weight
                          1-7                         0.5 - 1.5
                         8 - 14                       1.5 - 2.5
                       15 - 28                        2.5 - 3.5
                     (Hutcheson and Cole, 1986)

The remainder of this guide will focus on management practices and nutritional approaches to
development of a successful receiving program. For further information on vaccinations and
treatment protocols for receiving cattle refer to Receiving Cattle – Health and Treatment.

Management:
Before developing a nutritional program for receiving cattle producers must develop a location
suited to encourage feed and water intake. When calves arrive or are moved to a new location
they begin by walking the fence line. Placing water sources and feed bunks along the perimeter
of the pen will aid calves in discovering feed and water. Freshly weaned calves may have never
eaten from a bunk or drank from a water tank so they will not seek out these structures. Placing
feed and water along the fence line will not only aid in discovery but will minimizing constant
walking around the perimeter.
Providing water in a tank mimics pasture water locations such as ponds or creeks where calves
are able to see surroundings while drinking. Calves may be reluctant to drink from water sources
where they must enter a structure, raise a lid or depress floating covers. Consider temporarily
modifying water sources to minimize new experiences. In large pens where water sources may
be difficult to locate allow water to trickle over to encourage calves to locate the source. Clean
water sources daily during the first week cattle are received to assist cattle in locating water.

If calves were creep fed prior to weaning using a similar creep feeder in the receiving lot may aid
in providing a familiar feeding structure calves may seek out. Utilizing creep feed as part or all
of the receiving ration can also facilitate the weaning transition.

In bunk feeding systems provide adequate space to ensure all calves have access to feed. If fed
once daily calves require 18-22 inches of linear bunk space per head, if fed twice daily bunk
space requirements are 9 to 11 inches per head (MWPS, 1987). More frequent feeding will
encourage cattle to approach the bunk and aids in maintaining a fresh feed supply. Adequate
bunk space during receiving prevents dominate calves from overeating and allows timid cattle to
start on feed.

When starting cattle on feed offering hay in the feed bunk rather than a separate hay feeder helps
familiarize calves to bunk feeding. If hay is offered separate from the feed bunk timid calves
may not start on feed as quickly leading to digestive upset later in the feeding period. Offering
hay in the bunk also prevents calves from standing around the hay feeder at feeding and can help
identify sick cattle. Feed receiving diets on top of the hay the first week to encourage feed
intake.

Nutrition:
The most important nutrient to beef cattle is water due to involvement in nearly all body
processes. Water constitutes approximately 60% of the body depending on animal age. When
weaning or receiving cattle there are two theories of water management; offer water immediately
after arrival or withhold water for a short time period to prevent cattle from filling up on water
immediately after transportation.

Water restriction for 6-8 hours did not reduce or improve feed intake in short hauled cattle with a
2.6% shipping shrink (Bartle et al., 1987). In longer hauled cattle with 6.6% shrink (Bartle et al.,
1987) or cattle deprived of water for 12 hours or greater (Bond et al., 1976) feed intake was
reduced. Offering water on arrival to receiving or freshly weaned calves is the best management
practice to encourage dry matter intake.

Receiving cattle diets range from grass hay to complete milled feed. Individual producer and
feedyard receiving diet components and complexity vary due to available feedstuffs and mixing
capability. One constant among most receiving programs is the use of grass hay. Quality grass
hay is palatable to calves and aids in transitioning calve from pasture to drier feedstuffs.

As calves enter the receiving two distinct challenges must be balanced to maintain performance:
low initial dry matter intake and the opportunity to overeat once adapted to concentrate diets. To
address these challenges research has focused on determining the optimal balance of concentrate
in receiving diets. Considering calves will consume 0.5 to 1% of body weight in concentrate at
arrival diets must contain adequate nutrient concentrations to provide sufficient total nutrient
intake.

Ingredient source will impact the diet’s ability to provide sufficient nutrients during periods of
low intake. Use of wet feeds such and silage, haylage or wet distillers grains, wet corn gluten
feed or condensed distillers solubles provide energy yet require greater feed intake to consume
similar amounts of dry matter when compared to dry feeds. The fermented smell of silage and
haylage is foreign to calves fresh off pasture and may reduce intake. Fermented feeds will be
foreign to calves at any point of the feeding period, if silage or haylage are going to be part of the
diet consider adding at receiving and increase the concentration as calves adapt. Maintain a total
diet dry matter of 50% or greater when using wet feedstuffs in receiving diets.

In a series of experiments receiving calf performance was evaluated using 20%, 55%, 72% and
90% diets (Lofgreen et al., 1975). Calves fed the 72% concentrate receiving diet exhibited
consistent performance resulting in the research station adopting the 72% concentrate diet as the
standard for receiving cattle. Given the opportunity to select concentrate level, calves prefer
90% concentrate diets over 20% and 55% concentrate diets. Despite calves preference for
concentrate rations many producers receiving programs still center on providing access to grass
hay with supplementation.

New Mexico research demonstrated performance differences in receiving programs where grass
hay was offered the entire 42 day period or grass hay was supplemented with 2 pounds of protein
supplement or grass hay for the first week in combination with 75% concentrate during the
receiving period (Lofgreen and Kiesling, 1985). Offering grass hay the first week in
combination with a 75% concentrate diet resulted in calves with greater ADG and feed intake
compared to grass hay plus protein supplement or grass hay alone. High shrink calves (> 9%)
did not overcome performance differences by the end of the feeding period whereas low shrink
cattle (< 7%) were able to compensate by the end of the feeding period (Lofgreen and Kiesling,
1985). In cases where calves are weaned on the farm (low shrink) the use of quality long stem
hay may not impact final performance of the calf however performance during the receiving
period will be lower than calves on a higher plane of nutrition.

Including hay as part of the receiving ration was further supported when offering free choice
alfalfa hay in addition to a 75% concentrate diet during receiving improved average daily gain,
dry matter intake and feed efficiency compared to 75% concentrate alone (Lofgreen et al., 1980).
In a separate experiment calf performance was greatest when millet hay was offered in
combination with a 75% concentrate ration (Lofgreen et al., 1981).

One observation related to using concentrates in receiving diets, as energy content increased
number of calves requiring treatment also increased (Lofgreen et al., 1975; 1980; 1981). When
evaluated on treatment cost per pound of gain there were no differences due to concentrate level.
Rivera et al., (2005) summarized many of these observations and reported the small advantage in
reduced illness by increasing receiving diet roughage level was not offset by the performance
advantage in calves fed 50 to 75% concentrate receiving diets.
Protein requirements for receiving cattle are dependent on intake and performance level. Cole
and Hutcheson (1990) reported protein requirements for stressed cattle are not higher than
unstressed calves however low feed intake requires a greater protein concentration in the diet.

Calves fed a 12.5% CP receiving diet gained faster and consumed more feed than calves fed
10.5% CP (Eck et al., 1988). Feeding a 16% CP diet improved performance compared to a 12%
CP diet during the first 14 days of receiving (Cole and Hutcheson, 1990). Crude protein does not
address metabolizable protein or amino acid requirements of growing cattle. Protein source and
rumen degradation or bypass also contributes to protein requirements of receiving cattle.

Eck et al., (1988) reported providing rumen undergraded protein using blood and corn gluten
meal improved performance compared to urea in 10.5% and 12.5% CP diets when intake was
greater than 2.3% of body weight. Fluharty et al., (1994) reported improved performance in
receiving calves supplemented with undegraded protein using blood meal compared to soybean
meal at dry matter intakes of 1.2% of body weight. Other research has reported little to no
benefit to undegraded protein supplementation at intakes greater than 2.1% of body weight
(Lehmkuhler and Kerley, 2007; McCoy et al., 1998).

Preston (2007) suggested starting receiving cattle diets at 14-15% crude protein with 60% of
protein as undegraded intake protein. Protein level can be reduced as cattle increase feed intake.

Mineral and vitamin nutrition is commonly reported as a “key” component to a successful
receiving program. Numerous studies have evaluated potassium, copper, zinc, selenium and
vitamin E all thought to influence immune function. The effects of these nutrients, similar to
energy and protein, appear to be intake related. Calves have a requirement for each of these
nutrients however during receiving low dry matter intake results in nutrient deficiencies. These
deficiencies may be amplified during the stress of shipment or weaning.

Receiving potassium requirements are linked to water and tissue losses during shrink.
Hutcheson et al., (1984) reported K requirement for shipped cattle was 20% greater than
unshipped cattle. Increasing dietary potassium level to 1.8% of dry matter depressed intake
(Lofgreen, 1988). Current NRC (2000) recommendations suggest dietary K levels of 1.2 to 1.4%
of dry matter for stressed calves during receiving. As dry matter intake increases to 2% of body
weight K level should be reduced to 0.7% of diet dry matter.

NRC (2000) mineral and vitamin recommendations for stressed calves are shown in Table 2.
These recommendations are based on low dry matter intake during receiving. As calves increase
intake beyond 2% of body weight mineral and vitamin diet concentrations should be reduced as
current information does not support increased mineral and vitamin feeding levels (Galyean et
al., 1999).

Mineral source and bioavailability are another component to receiving cattle nutrition. Organic
or chelated mineral forms are options to improve mineral status due to increased bioavailability.
In situations where intake is low and prior nutritional status is poor, blends of organic and
inorganic sources may be warranted. Similar to other nutrients once the receiving period is
complete and cattle are on feed traditional and often times more economical sources will suffice.
                   Table 2. Suggested mineral and vitamin concentrations
                   for stressed calves (dry matter basis)
                   Nutrient               Suggested range      Unit
                     Calcium                  0.6-0.8           %
                     Phosphorus               0.4-0.5           %
                     Potassium                1.2-1.4           %
                     Magnesium                0.2-0.3           %
                     Sodium                   0.2-0.3           %
                     Copper                    10-15           ppm
                     Iron                    100-200           ppm
                     Manganese                 40-70           ppm
                     Zinc                     75-100           ppm
                     Cobalt                   0.1-0.2          ppm
                     Selenium                 0.1-0.2          ppm
                     Iodine                   0.3-0.6          ppm
                     Vitamin A             4000-6000            IU
                     Vitamin E               400-500            IU
                   (NRC, 2000)

Ionophores, coccidiostats, antibiotics, and direct-fed microbials are common feed additives to
receiving cattle diets. Ionophores improve performance and feed efficiency, have coccidiostat
properties and can prevent acidosis. Ionophore inclusion may reduce feed intake during
receiving. In high-stress cattle where intake is depressed delay or slowly introduce ionophores to
minimize feed intake depression. Calves commonly experience clinical or sub-clinical
coccidiosis making prevention using a coccidiostat or ionophore key during receiving.

Feed antibiotics are a management option for sickness prevention. However as previously
discussed sick animals have reduced feed intake making feed a marginal delivery mechanism for
antibiotic treatment.

Direct-fed microbial products have improved and had no effect on receiving cattle performance
and health status. If cattle are going to respond to direct-fed microbials the likelihood is greater
during times of stress such as weaning of receiving (Krehbiel et al., 2003).

Dry matter intake by calves during receiving influences diet composition relative to energy,
protein, minerals, vitamins and several feed additives. Given the need to increase nutrient
density and the costs associated with greater nutrient concentrations producers should consider
developing a specific nutritional program matching the receiving diet to projected dry matter
intake. The receiving nutritional program should fit into a management program designed to
encourage feed and water intake.
Literature Cited:
Bartle, S. J., T. P. Eck, and R. L. Preston. 1987. Dietary factors affecting feed intake in recieving
        feedlot cattle. Tex J Agric Nat Res 1: 21-23.
Bond, J., T. S. Rumsey, and B. T. Weinland. 1976. Effect of deprivation and reintroduction of
        feed and water on the feed and water intake behavior of beef cattle. J. Anim Sci. 43: 873-
        878.
Cole, N. A., and D. P. Hutcheson. 1990. Influence of dietary protein concentrations on
        performance and nitrogen repletion in stressed calves. J. Anim Sci. 68: 3488-3497.
Eck, T. P., S. J. Bartle, R. L. Preston, R. T. Brandt, Jr., and C. R. Richardson. 1988. Protein
        source and level for incoming feedlot cattle. J. Anim Sci. 66: 1871-1876.
Fluharty, F. L., S. C. Loerch, and F. E. Smith. 1994. Effects of energy density and protein source
        on diet digestibility and performance of calves after arrival at the feedlot. J. Anim Sci. 72:
        1616-1622.
Galyean, M. L., L. J. Perino, and G. C. Duff. 1999. Interaction of cattle health/immunity and
        nutrition. J anim sci 77: 1120-1134.
Hutcheson, D. P., and N. A. Cole. 1986. Management of transit-stress syndrome in cattle:
        Nutritional and environmental effects. J. Anim Sci. 62: 555-560.
Hutcheson, D. P., N. A. Cole, and J. B. McLaren. 1984. Effects of pretransit diets and post-
        transit potassium levels for feeder calves. J. Anim Sci. 58: 700-708.
Krehbiel, C. R., S. R. Rust, G. Zhang, and S. E. Gilliland. 2003. Bacterial direct-fed microbials
        in ruminant diets: Performance response and mode of action. J. Anim Sci. 81: E120-132.
Lehmkuhler, J. W., and M. S. Kerley. 2007. Blood meal and fish meal as supplements to increase
        the amino acid to energy ratio in steer receiving diets. The Professional Animal Scientist
        23: 253-259.
Lofgreen, G. P. 1988. Nutrition and management of stressed beef calves: An update. Vet Clin
        Food Anim 4: 509-522.
Lofgreen, G. P., J. R. Dunbar, D. G. Addis, and J. G. Clark. 1975. Energy level in starting rations
        for calves subjected to marketing and shipping stress. J. Anim Sci. 41: 1256-1265.
Lofgreen, G. P., A. E. El Tayeb, and H. E. Kiesling. 1981. Millet and alfalfa hays alone and in
        combination with high-energy diet for receiving stressed calves. J. Anim Sci. 52: 959-
        968.
Lofgreen, G. P., and H. E. Kiesling. 1985. Effects of receiving and growing diets on
        compensatory gains of stressed calves. J. Anim Sci. 61: 320-328.
Lofgreen, G. P., L. H. Stinocher, and H. E. Kiesling. 1980. Effects of dietary energy, free choice
        alfalfa hay and mass medication on calves subjected to marketing and shipping stresses.
        J. Anim Sci. 50: 590-596.
McCoy, R. A., R. A. Stock, T. J. Klopfenstein, D. H. Shain, and M. J. Klemesrud. 1998. Effect
        of energy source and escape protein on receiving and finishing performance and health of
        calves. J. Anim Sci. 76: 1488-1498.
MWPS. 1987. Beef housing and equipment handbook. 4th ed. Iowa State University, Ames, IA.
NRC. 2000. Nutrient requirements of beef cattle. 7th rev. ed. National Academy Press,
        Washington DC.
Preston, R. L. 2007. Receiving cattle nutrition. Vet Clin Food Anim 23: 193-205.
Rivera, J. D., M. L. Galyean, and W. T. Nichols. 2005. Review: Dietary roughage concentration
        and health of newly received cattle. The Professional Animal Scientist 21: 345-351.
FORAGE SAMPLING AND ANALYSIS INTERPRETATION
Zac Erwin
Extension Livestock Specialist

Many different factors affect forage quality. Some variables include: plant species (legumes,
grasses, and weeds), stage of maturity during harvest, environmental conditions during growth
and harvest, insect and plant disease damage, soil fertility, and losses during harvest and storage.
Forage testing is used to estimate the nutritional value of forage for livestock rations. The
information attained is only useful if correctly applied in the development and feeding of
balanced rations, or in other cases hay marketing. Knowing the nutritional value of forages, and
using that information in ration formulation can help cut feed costs—the biggest expense in a
cow/calf operation. The first and most important step in obtaining a meaningful analysis is to
collect a representative forage sample.

Taking Samples:
Sampling is where some of the biggest errors can occur in attempts to analyze the quality of
forage resources. To be useful, a forage analysis report should be based on a representative
sample from a single “lot” of hay. A “lot” is hay from one field which has been cut, handled,
baled, and stored under consistent conditions. The sample should be a consolidation of cores
taken from 15 to 20 bales. It is important to not combine hays of different qualities or cuttings
into one combination sample in an attempt to save money. The resulting analyses information
will not be useful for making feeding decisions. (ISU, 2008)
The best time to take hay or silage samples is as near to the time of feeding or sale as possible.
Sampling after periods of storage will account for heat or weather damage that has occurred
during storage. Allow enough time for mailing, laboratory work, and ration formulation, which
may require several days to a week or more.
Sampling Methods (Drazkowski, 1998):
Proper approaches to sampling methods vary between square bales, round bales, and silage.
Suggested sampling methods are:

    x Small square bales—Take core samples through the center of one end of the bale, 12-
      15” deep.
    x Large square bales—Take core samples at waist height on the rounded side of the bale,
      12-15” deep.
    x Silages—All spoiled material should be removed prior to sampling. When sampling at
      feed out: collect grab samples at both morning and evening feeding when feeding a new
      silage lot. The accumulated grab samples (weighing 2-3 pounds) should be thoroughly
      mixed, sealed in a plastic bag and frozen for shipment to the testing lab. If sampling
      during filling, collect a representative handful or two of chopped forage from each of
      several loads coming from that field; squeeze out excess air and store the samples in a
      sealed plastic bag in the freezer. For large fields harvested over several days, collect two
      to four handfuls of chopped forage from each of several loads during each day. Combine
      all the samples from the field in a sealed plastic bag and submit this large, composite
      sample to the laboratory, frozen.
    x Stacks and piles—Remove spoiled material and sample 18” deep.

It seems more practical to sample silage during filling. While there are some nutritional changes
during normal fermentation, nutritional changes are usually small. However, if forage is stored
‘too wet’ and the silo ‘seeps’ or it is stored ‘too dry’ and the silage heats excessively during
ensiling, consider resampling by taking several grab samples at feed out.
Baled wet or wilted forage being stored as bale silage can be sampled as other silage, either core
sampling bales before wrapping for bale silage, or core sample the wrapped bales nearer the time
of feeding. If sampled, plastic wrapped bales are not being fed immediately, reseal quickly to
prevent unnecessary spoilage.

Interpreting Results:
Analysis report forms may vary from laboratory to laboratory, but usually contain information on
moisture (%), dry matter (DM, %), crude protein (CP, %), acid detergent fiber (ADF, %), neutral
detergent fiber (NDF, %), total digestible nutrients (TDN, %), and net energy calculations for
lactation (NEL, mcal/lb), maintenance (NEM, mcal/lb, gain (NEG, mcal/lb), and relative feed
value (RFV) on alfalfa.

Definitions:
Moisture is expressed as a percent, calculating the water present in the forage analyzed. Dry
matter (DM) is the percentage of the forage that is not water. Crude Protein (CP) is the sum of
true protein and non-protein nitrogen. It is calculated by measuring the nitrogen concentration
and multiplying by 6.25. Acid detergent fiber (ADF) is the percentage of highly indigestible
plant material present in a forage. ADF is a useful predictor of energy and digestibility in
forages. Low ADF values mean higher energy value and digestibility. Neutral detergent fiber
(NDF) represents all structural or cell wall material in the forage. NDF of a forage is inversely
related to the amount that a cow or calf is able to consume. Forages with low NDF will have
higher intakes than those with high NDF. (NRC, 2000)

Energy Terms:
Total digestible nutrients (TDN) report the percentage of digestible material in a forage. TDN
is calculated from ADF and expresses the differences in digestible material between forages.
Net energy of maintenance (NEM) and lactation (NEL) are expressions of energy value of
forage in megacalories per pound (Mcal/lb); and refer to the forage’s ability to meet the energy
requirements of dairy and beef cattle. Dairy producers generally use NEL to balance rations for
lactating cows, while beef producers generally us NEM. Net energy for gain (NEG) is the amount
of energy in a forage available for growth after the maintenance needs have been met. NEG is
used in conjunction with NEM when estimating the forage’s ability to put weight on growing
animals. (Henning, 1996)

Summary:
Interpreting forage analysis reports is a two-step process. An understanding of the basic
terminology and meaning of the important components of the report must first be achieved.
Then you must evaluate the forage’s ability to generate a desired level of animal performance
when consumed. Understanding a forage test is easiest when it is explained in animal
performance terms. Numerous computer programs exist to aid in the process of converting a
forage test into animal performance measures. Using an Extension livestock specialist or other
trained professionals is highly recommended when looking to cut feed costs or achieve specific
animal performance.

References:
Drazkowski, Steve. 1998. Forage Sampling and Interpretation Lesson 4. University of
      Minnesota Extension Service.
Henning, J.C., G.D. Lacefield, and D. Amaral-Phillips. 1996. Interpreting Forage Quality
      Reports. Cooperative Extension Service University of Kentucky.
Iowa State University. 2008. Forage Sampling and Sampling Equipment.
National Research Council. Nutrient Requirements of Beef Cattle. 2000. National Academy
       Press.
EVALUATION OF THE UTILITY AND ECONOMICS OF HIGH-INPUT
VS. LOW-INPUT CORN PRODUCTION SYSTEMS IN MISSOURI
Kevin Bradley                                Bruce Hibbard
Assistant Professor                                                 Adjunct Associate Professor
Laura Sweets                                                                      Ray Massey
Extension Associate Professor                                               Extension Professor
                                                                               Wayne Bailey
                                                                            Associate Professor
2007 and 2008 Results
Impact of Herbicide Programs on Weed Control and Corn Yield:
The results from the first two years of these experiments are presented in Tables 1-8. As
illustrated in Table 1, the preemergence only (PRE-only) program of Lexar and the early
postemergence (E-POST) application of Aatrex plus Callisto plus Steadfast (conventional 1-pass
POST program) generally resulted in the highest weed densities by the time of corn tasseling at
both sites in 2007 and 2008. Very few differences in weed density at tasseling have been
observed with the other herbicide programs evaluated in these trials. As shown in Table 2, these
weed densities caused corn yield reductions at the 2007 Novelty and 2008 St. Elizabeth research
sites, but not at the 2007 St. Elizabeth site.

The results in Table 1 also show the inconsistency that can occur with a conventional 1-pass
POST program compared to a Roundup Ready 1-pass POST program. Weed density in response
to the Roundup Ready 1-pass POST program was significantly less at every site except the 2008
Novelty research location. Throughout our research, we have seen more inconsistency with the
conventional POST-only programs in comparison to the POST-only programs containing
glyphosate for use in Roundup Ready corn.

Other than the exceptions described above, the results from the first two years of this research
illustrate that good weed control and optimum corn yields can be achieved with a variety of
herbicide program approaches. The PRE followed by POST conventional and glyphosate
programs performed similarly from the standpoint of weed control and yield, which confirms
that producers can still grow conventional corn and achieve excellent weed control and high corn
yields.

Impact of Stacked Corn Hybrids on Insect Injury and Yield:
As illustrated in Table 3, corn hybrids stacked with protection against European Corn Borer
(ECB) and both ECB and corn rootworm (RW) increased corn yields at the St. Elizabeth site in
2007 and 2008 but not Novelty in 2007 where no rootworm pressure was present. Corn
rootworm damage was significantly lower to the RR/ECB/RW hybrid than all other hybrids at
the 2007 St. Elizabeth site, but only minor root damage was observed at the 2008 St. Elizabeth
site (Table 4). In 2008, both stacked hybrids resulted in significant reductions in ECB tunneling
and average tunnel length compared to the RR hybrid without insect protection (Table 5). This
may help to explain the 4- to 5-bushel per acre reduction in corn yield observed with the RR
compared to the stacked hybrids at the 2008 St. Elizabeth site (Table 3).
Impact of Fungicide Application on Disease Incidence and Corn Yield:
The application of Headline fungicide at tasseling caused significant yield increases compared to
untreated corn at the 2007 Novelty and the 2008 St. Elizabeth research sites (Table 6). Corn
yields were increased by 6 bu/A at both sites in 2007 and by 14 bu/A at the St. Elizabeth site in
2008. Approximately 6 weeks after Headline treatment, common rust severity was greater in
untreated corn compare to corn treated with Headline at both locations in 2008 (Table 7).
Similarly, grey leaf spot severity was higher in untreated corn compared to corn treated with
Headline at the 2008 Novelty site (Table 7). It is unlikely that the observed yield increases can
be attributed to these relatively low levels of grey leaf spot and common rust severity, therefore
additional measurements were taken in each plot to measure the relative chlorophyll content in
untreated corn compared to corn treated with Headline. As illustrated in Table 8, chlorophyll
content was higher in the ear leaf and the ear leaf -2 in corn treated with Headline versus
untreated corn.
Table 1. Influence of herbicide programs on weed density at tasseling at St. Elizabeth and Novelty, Missouri in
2007 and 2008.
─────────────────────────────────────────────────────────────────
                                                                                Research Site
                                                       ────────────────────────────────
                                                                St. Elizabeth                   Novelty
                                       Application     ─────────────── ───────────────
Treatmentsb               Rate           Timing            2007             2008           2007            2008
─────────────────────────────────────────────────────────────────
                   --- product/A ---                   ----------------- Total Weed Density (#/m2)a -----------------

Lexar                     3 qts              PRE              46 b           10 c            17 b          30 b

Lexar                     3qts               PRE              11 d             6c             3c           20 bc
Roundup Omax            22 fl ozs           POST

Lexar                    3 qts               PRE              10 d             3c             4c           14 bc
Aatrex                    1 pt              POST
Callisto                3 fl ozs            POST

Lexar                    1.5 qts            PRE               14 d             5c             4c           13 bc
Roundup Omax            22 fl ozs           POST

Lexar                   1.5 qts              PRE              12 d             8c             9c           10 c
Aatrex                    1 pt              POST
Callisto                3 fl ozs            POST

Halex                    3.6 pts           E-POST             11 d             5c             3c           13 bc
Aatrex                    1 pt             E-POST

Aatrex                    1 qt             E-POST             26 c           27 b            10 c          25 bc
Callisto                2 fl ozs           E-POST
Steadfast                ¾ oz              E-POST

Untreated               -------           -------            64 a    71 a 52 a 148 a
─────────────────────────────────────────────────────────────────
  a
   Means followed by the same letter are not different, P < 0.05.
  b
    All postemergence treatments applied with recommended adjuvants.
Table 2. Influence of herbicide programs on corn yield at St. Elizabeth and Novelty, Missouri in
2007 and 2008.
─────────────────────────────────────────────────────────
                                                                                 Research Site
                                                        ────────────────────────
                                                                 St. Elizabeth             Novelty
                                       Application       ─────────────── ───────
Treatmentsb               Rate           Timing              2007             2008           2007
─────────────────────────────────────────────────────────
                   --- product/A ---                    --------------- Yield (Bu/Acre)a ---------------

Lexar                     3 qts              PRE               87 a          181 ab           145 b

Lexar                     3qts                PRE              91 a          181 ab          154 a
Roundup Omax            22 fl ozs            POST

Lexar                     3 qts               PRE              91 a          184 ab          155 a
Aatrex                     1 pt              POST
Callisto                 3 fl ozs            POST

Lexar                    1.5 qts             PRE               94 a          189 a           154 a
Roundup Omax            22 fl ozs            POST

Lexar                    1.5 qts              PRE              88 a          176 b           155 a
Aatrex                     1 pt              POST
Callisto                 3 fl ozs            POST

Halex                    3.6 pts           E-POST              88 a          184 ab          155 a
Aatrex                    1 pt             E-POST

Aatrex                     1 qt            E-POST              95 a          146 d           146 b
Callisto                 2 fl ozs          E-POST
Steadfast                 ¾ oz             E-POST

Untreated               -------           -------            61 b    156 c 119 c
─────────────────────────────────────────────────────────
  a
   Means followed by the same letter are not different, P < 0.05.
  b
    All postemergence treatments applied with recommended adjuvants.
Table 3. Influence of insect resistance traits in near-isogenic corn
hybrids on corn yield at St. Elizabeth and Novelty, Missouri in
2007 and 2008.
──────────────────────────────────────
                                          Research Site
                       ─────────────────────────
                                St. Elizabeth             Novelty
Near-Isogenic            ─────────────── ────────
Corn Hybrid                  2007            2008           2007
──────────────────────────────────────
                       --------------- Yield (Bu/Acre)b ---------------

RR                         76 b           172 b           147 a
RR/ECBb                    88 a           177 a           150 a
RR/ECB/RWc                 96 a           176 ab          147 a
──────────────────────────────────────
   a
    Means followed by the same letter are not different, P < 0.05.
   b
     Contains the Cry 1A protein for European corn borer control.
   c
    Contains both the Cry 1A protein for European corn borer
control and Cry 3Bb1 protein for rootworm control.




Table 4. Influence of insect resistance traits in near-
isogenic stacked corn hybrids on root damage caused
by corn rootworm at St. Elizabeth, Missouri in 2007
and 2008.
────────────────────────────────
                              Rootworm Damagea
Near-isogenic           ──────────────────
Corn Hybrids                2007                2008
────────────────────────────────
                       --------- Average/Plantb ---------

RR                         0.44 b            0.035 a
RR/ECBc                    0.55 a            0.028 ab
RR/ECB/RWd                 0.10 c            0.019 b
────────────────────────────────
   a
    Root damage assessed using a linear 0-3 root
damage scale (Oleson et al. 2005).
   b
     Means followed by the same letter are not different,
P < 0.05.
   c
    Contains the Cry 1A protein for European corn borer control.
   d
     Contains both the Cry 1A protein for European corn borer
control and Cry 3Bb1 protein for rootworm control.
Table 5. Influence of insect resistance traits in near-isogenic stacked corn hybrids on tunneling
and tunnel length caused by European corn borer at St. Elizabeth and Novelty, Missouri in
2008a.
───────────────────────────────────────────────────────
                                 St. Elizabeth                                Novelty
Near-isogenic         ────────────────────                      ────────────────────
Corn Hybrids             Tunneling        Tunnel Length            Tunneling       Tunnel Length
───────────────────────────────────────────────────────
                        -- #/Plant --       ---- mm ----          -- #/Plant --      ---- mm ----

RR                         0.43 a           15.3 a                 0.26 a         5.80 a
RR/ECBb                   0.03 b             0.6 b                 0.02 b         0.17 b
RR/ECB/RWc                0.03 b             0.4 b                 0.02 b         0.13 b
───────────────────────────────────────────────────────
   a
    Means followed by the same letter are not different, P < 0.05.
   b
     Contains the Cry 1A protein for European corn borer control.
   c
    Contains both the Cry 1A protein for European corn borer control and Cry 3Bb1 protein for
rootworm control.




Table 6. Influence of HeadlineTM fungicide application on corn
yield at St. Elizabeth and Novelty, Missouri in 2007 and 2008.
──────────────────────────────────────
                                            Research Site
                        ─────────────────────────
                                  St. Elizabeth             Novelty
                          ─────────────── ────────
Treatments                    2007             2008           2007
──────────────────────────────────────
                         --------------- Yield (Bu/Acre)a ---------------

Headline @ Tasseling     90 a           182 a            151 a
No Fungicide             84 a           168 b            145 b
──────────────────────────────────────
  a
   Means followed by the same letter are not different, P < 0.05.
Table 7. Influence of HeadlineTM fungicide application on gray leaf spot and
common rust severity 6 weeks after application at St. Elizabeth and Novelty,
Missouri in 2008.
──────────────────────────────────────────────
                                                 Research Site
                        ────────────────────────────────
                                St. Elizabeth                        Novelty
                        ─────────────── ───────────────
                            Gray           Common            Gray            Common
Treatments               Leaf Spot            Rust         Leaf Spot            Rust
──────────────────────────────────────────────
                       ------------------------- Severity (%)a,b -------------------------

Headline @ Tasseling      0.006 a         0.047 b        0.076 b      0.004 b
No Fungicide              0.013 a         0.214 a        1.009 a       0.394 a
──────────────────────────────────────────────
   a
    Means followed by the same letter are not different, P < 0.05.
   b
     Severity was determined by estimating percent of ear leaves showing gray
leaf spot or rust symptoms for 10 ear leaves per plot.




Table 8. Influence of HeadlineTM fungicide application
on relative chlorophyll content of corn leaves at St.
Elizabeth, Missouri in 2008.
────────────────────────────────
                               Corn Leaf Position
                         ──────────────────
Treatments                 Ear Leaf         Ear Leaf -2
────────────────────────────────
                         -- Chlorophyll Content (%)ab –

Headline @ Tasseling       53.3 a            52.7 a
No Fungicide               51.8 b            50.6 b
────────────────────────────────
   a
    Means followed by the same letter are not different,
P < 0.05.
   b
     Chlorophyll content determined with a Minolta 502
SPAD meter.
GLYPHOSATE TANK-MIXES IN ROUNDUP READY SOYBEAN
Kevin Bradley
Assistant Professor

It seems that each year there are more calls and questions about glyphosate tank-mix partners in
Roundup Ready soybean. Based on all of the research I have done in this area over the past six
years, my answer to the question of using a tank-mix partner with glyphosate falls into two
categories:

1.) If you don’t think you have glyphosate-resistant weeds present.

   If you have a field where the weeds (including waterhemp) have gotten tall and you DON’T
   suspect you have any glyphosate-resistant weeds present, then our research shows that
   increasing the rate of glyphosate will generally provide as good or better weed control than
   adding a tank-mix partner to glyphosate in Roundup Ready soybeans. There may be some
   exceptions to this statement if you are dealing with weeds that have a natural tolerance to
   glyphosate. For example, a Resource tank-mix can sometimes provide better morningglory
   control than even a higher-than-normal rate of glyphosate. Also, there are some weeds like
   Asiatic dayflower and field horsetail that we are probably never going to kill with glyphosate
   and a tank-mix can often help with these kinds of weed species. For the most part however,
   our research has shown that if there are no resistant weeds present, our “normal” spectrum of
   weeds in Missouri will usually be controlled as good or better by a higher rate of glyphosate
   compared to a standard glyphosate application with a tank-mix partner. Another way of
   saying it is to take the money you were going to spend on the tank-mix partner and put that
   money towards a higher rate of glyphosate per acre.

2.) If you suspect you have a glyphosate-resistant weed present.

   The other side of the coin is if you suspect that you do have a glyphosate-resistant weed like
   waterhemp present, then a tank-mix partner can be very beneficial. Increasing the rate of
   glyphosate in this case will rarely provide better weed control and will almost certainly cost
   you more money.

   In our research with glyphosate-resistant waterhemp (see black bars in graph below), we
   found that the addition of Ultra Blazer at 1.5 pts/A, Flexstar at 12 fl ozs/A, or Phoenix at 8 fl
   ozs/A to a standard rate of glyphosate provided from 77 to 85% control of glyphosate-
   resistant waterhemp six weeks after treatment. This is compared to only 22% control of
   glyphosate-resistant waterhemp that was achieved with a standard rate of glyphosate alone.
   As you can see from the remainder of the results in this graph, other tank-mix partners like
   Aim, Butyrac, and Firstrate were highly ineffective on glyphosate-resistant waterhemp.
   Resource provided some control compared to glyphosate alone, but as this graph clearly
   shows, there are better options for waterhemp control than Resource.

   Although all of the research in this graph was conducted prior to the introduction of Cadet
   onto the marketplace, subsequent studies we have conducted with this herbicide have shown
   that tank-mixes of this product with glyphosate are also ineffective on glyphosate-resistant
   waterhemp, or even on glyphosate-susceptible waterhemp that has gotten too tall. The label
   of this product clearly shows control of 2-inch waterhemp with 0.9 fl ozs of Cadet per acre.
   This does not translate into control of 24-inch waterhemp with tank-mixes of the same rate!

   If you suspect you have other glyphosate-resistant weeds like common or giant ragweed
   present, then tank-mixes of the PPO-inhibiting herbicides like Ultra Blazer, Flexstar, and
   Cobra/Phoenix are probably still going to be your best option. Although for the most part
   Firstrate and some of the other ALS-inhibiting herbicides continue to have good activity on
   common and giant ragweed in Missouri, these herbicides are also very sensitive to weed
   height. This means that when the ragweeds get over one foot or so in height, the likelihood
   of controlling them with these herbicides goes down dramatically.

Finally, as far as tank-mix partners are concerned I think one of the biggest things we need to
avoid is the temptation to use a tank-mix partner just because it only adds another $1 or $2 per
acre to the total application cost. Also, we should be aware of the potential for antagonism of
some of these products with glyphosate. Just because a product appears to control weeds
quicker, that doesn’t always mean that the product or tank-mix treatment is better. In our
research where we have the ability to compare different tank-mix treatments side-by-side, we
will often rate a tank-mix treatment higher than a glyphosate-only treatment 3- to 5-days after
application. However, when we come back and rate those same treatments 10- to 14-days after
application, we will often see no differences in overall weed control between the tank-mixes and
the glyphosate-only treatment.
DELINEATION OF HIGH RISK FIELD AREAS FOR VARIABLE
SOURCE N FERTILIZER APPLICATIONS TO OPTIMIZE CROP N USE
EFFICIENCY
Peter Motavalli                                Kelly Nelson
Associate Professor                                                         Research Agronomist
Steve Anderson                                                                      Paul Tracy
Professor                                                 Director of Agronomy Services - MFA

Research was conducted in 2007 and 2008 in Northeast Missouri to collect information related to
spatial and temporal differences in soil water content and soil N availability across agricultural
fields containing low-lying or depressional areas, to determine the spatial variability in crop
response and plant N status due to application of different enhanced efficiency N fertilizer
sources, and to develop and validate a computer program that would delineate the high risk N
loss areas in a form that could be used for variable source N fertilizer application.

•   In both years of this research, corn grain yields and plant N status increased significantly
    with an application of enhanced efficiency fertilizer sources (i.e. urea, polymer-coated urea
    (PCU), urea + urease inhibitor (UI) and urea + nitrification inhibitor (NI)) compared to the
    non-treated control depending on the landscape position. However, PCU was the only
    enhanced efficiency N source that had significantly higher average grain yields (20.4
    bu/acre higher in 2007 and 50.0 bu/acre higher in 2008) compared to that of urea over all of
    the landscape positions.
•   Maps of the grain yield differences between the enhanced efficiency N fertilizers and urea
    across the field indicate that in 2007 these enhanced efficiency fertilizers mainly out yielded
    urea in the low-lying areas of the field, probably due to differences in the fate of these
    fertilizers compared to urea under wetter soil conditions in the lower landscape positions of
    the field. These results confirm earlier research in the same field which observed
    consistently higher yields when PCU was applied compared to urea in low-lying areas.
•   Higher than average rainfall in 2008 (approximately 35 inches during the growing season)
    and extended periods of saturated soils in the lower areas of the field, resulted in relatively
    higher yields in the upper landscape positions. Among the enhanced efficiency N fertilizers,
    PCU showed consistently higher yields compared to urea across all landscape positions.
•   Maps of the net economic return for the enhanced efficiency fertilizers versus urea also
    show that strategic placement of these products in high risk areas of a field increased
    economic returns over a uniform application of urea or the enhanced efficiency fertilizers in
    claypan soils, especially in areas where there is variation in elevation and drainage.
•   The relative performance of PCU, UI and NI in this research may be affected by the fact that
    all the fertilizers were immediately incorporated after application compared to surface
    application.
•   Further testing and development of the variable source N fertilizer application strategy and
    an accompanying software tool are needed under different environmental conditions and on
    a farm field scale.

A field trial planted to corn was conducted in 2007 and 2008 at the University of Missouri
Greenley Research Center in Northeastern Missouri. This field was previously mapped for
elevation with a total station surveying instrument and apparent electrical conductivity (ECa)
using an EM-38 sensor. Relatively higher ECa indicates a relatively shallow depth to the claypan
subsoil layer. The field was selected because it contained contrasting landscape positions,
including low-lying areas, and differences in depth to the claypan layer.

The field was separated into 10 x 750 foot plots which passed through the low-lying and
sideslope areas of the field. Nitrogen fertilizer treatments consisted of a non-treated control and
150 lb N/acre of urea, polymer-coated urea (ESN, Agrium, Inc.), urea + NBPT (N-(n-butyl)
thiophosphoric triamide) urease inhibitor (UI) at 1 gal/ton (Agrotain, Agrotain International), and
urea + nitrapyrin nitrification inhibitor (NI) at 1 qt/acre (N-Serve, Dow AgroSciences) were
applied in the spring prior to planting of corn. All the N fertilizer treatments were incorporated
using a field cultivator immediately after application. The experimental design was a
randomized complete block with four replications.

In each plot, sampling points were set up every 30 feet across the field to allow for periodic
collection of soil samples from the 0 to 6 and 6 to 12 inch depths during the growing season for
determination of soil water content and soil inorganic N (ammonium and nitrate-N). Three
subsamples were taken at each point and composited. All the sampling points were
georeferenced using a differential GPS. Figure 1 shows the distribution of soil water content on
June 4th, 2007 indicating the variation in soil water content that occurred across this field. In
general, the low-lying areas had higher relative soil water content compared to that of the areas
with higher elevation. Two additional soil samplings were taken during the 2007 growing
season and two soil samplings were taken in June and July, 2008. The soil water content and soil
inorganic N levels from the 2008 samplings are still being analyzed.

Sub-plots of 28 ft in row length were established in each 750 foot long plot in order to assess the
interactive effects of N treatment and landscape position on grain yield and plant N status. This
resulted in approximately 23 to 27 subplots in each main plot. In order to assess the relative N
status of the corn plants, chlorophyll meter readings were taken using a SPAD 502 Chlorophyll
meter (Minolta Corp.) on 10 ear leaf subsamples on July, 30 2007 and August, 12 and 13, 2008.
Ear leaf samples were collected on the same day for determination of tissue N concentration.
Corn grain was harvested from the 28 foot row length between the sampling points on Sept. 19,
2007 and Oct. 6, 2008 using a two-row plot combine.

Relative yield performance of the enhanced efficiency N fertilizers (i.e., PCU, UI and NI) was
assessed by taking the yield differences between the individual enhanced efficiency fertilizer and
urea for each adjacent sub-plot in each replication. The relative economic benefit of the
enhanced efficiency N fertilizer was assessed by calculating the increase or decrease in value of
using the enhanced efficiency fertilizer compared to use of urea minus the additional cost of the
enhanced efficiency fertilizer compared to urea. The calculations were based on a corn price of
$4/bushel and an extra cost of $0.10/lb N for PCU, $0.05/lb N for UI and $0.06/lb N for NI.
The difference in cost of application for these enhanced efficiency fertilizers compared to that of
urea were not included in the calculation.
The differences in timing and amount of rainfall in 2007 and 2008 (Fig. 1A & B) had a large
impact on crop growth and yields (Table 1). In 2007, heavy spring rain delayed treatment
application and planting but cumulative rainfall during the growing season was only 11.9 inches
(Fig. 1A). In contrast, the 2008 growing season was characterized by heavy rainfall throughout
the season which delayed planting and resulted in standing water in the low-lying area of the
field for extended periods (Fig. 1B). Poor seed germination in several low-lying subplots in
2008 led to poor or non-existent plant stands in those sub-plots (data not shown). Cumulative
rainfall during the 2008 growing season was 35.0 inches, approximately three times greater than
2007.

Table 1 shows the average grain yields, chlorophyll meter readings and ear leaf tissue N across
each plot for 2007 and 2008. The 2008 ear leaf tissue N concentrations are being analyzed.
Based on this analysis, all N fertilizer applications increased grain yields over the non-treated
control in 2007 and 2008. Grain yields with the excessive rainfall in 2008 were also generally
lower than those of 2007. In comparing the performance of the enhanced efficiency N fertilizers,
polymer-coated urea (PCU) had significantly higher grain yields compared to urea. It is
important to note that the relative performance of the enhanced efficiency fertilizers may have
been affected by the fact that in this research all the N treatments were immediately incorporated
after application. For example, UI has been found to be effective in reducing ammonia
volatilization of surface-applied urea. Therefore, incorporation of the urea may lower the
relative effectiveness of the UI in reducing N loss.

The chlorophyll meter readings and the ear leaf tissue N concentration, which are relative
measures of the N status of the plant, were significantly higher when N fertilizer was applied.
However, the PCU treatment was the only enhanced N fertilizer treatment which had a
consistently significantly higher average chlorophyll meter reading compared to urea in 2007 and
2008. Both the chlorophyll meter readings and ear leaf tissue N were good indicators of grain
yield in 2007 (Fig. 2A) and 2008 (Fig. 2B) (ear leaf and yield data not shown) suggesting a large
yield response to N availability in this field as influenced by landscape position and weather
conditions.

Significant variation in grain yield response to each N fertilizer treatment also occurred across
the field in both 2007 and 2008 (data not shown). In 2007, the highest yields tended to occur in
the lowest landscape positions of the field, but in 2008 because of the excessive saturation of the
soil, higher yields occurred in the higher landscape positions. An approach we are using to
determine the areas in the field which would have the greatest grain yield response to the
enhanced efficiency fertilizers is to map the differences in yields between urea and the enhanced
efficiency fertilizer. Figures 3 and 4 show the results of mapping the differences in yield
between the PCU-, NI- and UI-treated plots and the urea-treated plots. Positive yield differences
indicate the enhanced efficiency N fertilizer-treated area yield was greater than the urea-treated
area. When this yield difference is zero or negative then urea was equivalent to or greater than
the enhanced efficiency fertilizer. Based on the yield differences and relative price difference
between urea and enhanced efficiency fertilizers, we also mapped the net economic return from
using these products compared to urea in 2007 (Fig. 3) and 2008 (Fig. 4).
The results of these analyses showed large differences in relative yield performance across the
field which affected the relative economic return. For example, in 2007 the low-lying region in
the field had greater yield response to the PCU fertilizer compared to urea (Fig. 3A). Based on
an economic analysis, the increased value of using PCU versus urea minus its extra cost was
highest in the low-lying area while urea was more cost-effective on the sideslope (Fig. 3B). In
contrast, in 2008, the yield and economic benefits of using PCU was positive over the whole
field and was highest in the upper positions of the field (Fig. 4A). For 2008, PCU showed the
highest economic benefit of all the enhanced efficiency N fertilizer treatments with some
locations in the field having over a $400/acre economic benefit by adding PCU compared to urea
(Fig. 4A). Use of NI and UI also showed variation in yield and economic benefit compared to
urea alone across the field in both years (Fig. 3B&C and 4B&C)). As with the use of PCU in
2007, these products also had areas of the field where use of these products resulted in a negative
economic return compared to using urea alone, possibly due to lower grain yields or the extra
cost of using these products.

An initial effort at developing software to delineate the areas in the field that will respond to
enhanced efficiency N fertilizers was undertaken, but further funding is required to continue
development and conduct testing for commercial use. This software would be of utility to
producers who wish to apply the enhanced efficiency N fertilizers to areas of a field where the
potential yield and economic benefits would be optimal. Further testing of what we are calling a
“variable source” fertilizer application approach to N fertilization with enhanced efficiency N
fertilizers needs to be undertaken in larger production fields, in different soil types, and with use
of commercially available multi-bin fertilizer spreaders since all of the research conducted so far
has been done on a relatively limited field area in claypan soils in Missouri.
Table 1. Average grain yields, chlorophyll readings and earleaf tissue N across the field in 2007
and 2008 due to applications of different enhanced efficiency N fertilizers.

                             Grain yield                 Chlorophyll reading          Ear leaf tissue N
    N treatment         2007             2008            2007            2008               2007
                    ---------- bu/acre -----------   --------- Spad units ---------        -- % --
Control                70.0               29.1            33              27                1.30
Urea                  130.1               48.9            51              31                2.02
PCU                   150.5               99.8            55              40                2.15
Urea + UI†            133.4               61.1            52              31                2.00
Urea + NI§            136.8               57.6            52              32                2.14

LSD(0.05)*             15.0              12.6              3                4               0.32
†
 Urea + urease inhibitor
§
 Urea + nitrification inhibitor
* LSD(0.05) = Least Significant Difference at p < 0.05
                           5.0                                                                       40
                                    A. 2007




                                                                                                          Cumulative precipitation
Precipitation (inches)


                           4.0
                                                                                                     30
                                     Corn planted &
                                       treatments




                                                                                                                 (inches)
                           3.0           applied
                                                                             Corn                    20
                                                                           harvested
                           2.0
                                                                      11.9 inches
                                                                                                     10
                           1.0


                           0.0                                                                       0


                           5.0                                                                       40
                                                                                       35.0 inches
                                   B. 2008




                                                                                                          Cumulative precipitation
Precipitation (inches)




                           4.0
                                                                                                     30
                                      Corn planted &
                                        treatments                                       Corn
                                          applied




                                                                                                                 (inches)
                           3.0                                                         harvested

                                                                                                     20
                           2.0

                                                                                                     10
                           1.0


                           0.0                                                                       0
                             Apr      May        Jun       Jul      Aug       Sep       Oct        Nov


                         Figure 1. Daily and cumulative rainfall over the growing season at the
                         Greenley Center in A) 2007 and B) 2008.
                                          0 – 6 inch                  6 – 12 inch




          0 – 6 inch




           6 – 12 inch




                          N

Figure 1. Map of soil water content distribution at the 0 to 6 and 6 to 12 inch
depths in the experimental field on June 4, 2007. Lines represent the contour
intervals with elevations above sea level given in meters.
                        250
                                 A. 2007
                        200
Grain yield (bu/acre)




                        150


                        100


                         50                                           Y = 2.97X - 19.86
                                                                       2
                                                                      R = 0.62, P< 0.0001
                                                                      n = 486
                          0



                        250

                                 B. 2008
                        200
Grain yield (bu/acre)




                        150


                        100


                         50                                           Y = 4.39X - 82.66
                                                                       2
                                                                      R = 0.90, P< 0.0001
                                                                      n = 495
                          0

                           10          20          30          40          50          60          70
                                                   Chlorophyll reading
                                                       (Spad units)

                        Figure 2. Relationship between chlorophyll meter readings and grain yield for
                        all treatments in A) 2007 and B) 2008.
A. PCU




B. NI




C. UI




 Figure 3. Field maps showing spatial differences in corn grain yields and
 economic benefits with application of polymer-coated urea (PCU), nitrification
 inhibitor (NI) and urease inhibitor (UI) compared to urea in 2007. Note the
 differences in legend scales among maps for each N treatment. Numbers along
 contour lines are elevation in feet above sea level.
  A. PCU




   B. NI




   C. UI




Figure 4. Field maps showing spatial differences in corn grain yields and economic
benefits with application of polymer-coated urea (PCU), nitrification inhibitor (NI)
and urease inhibitor (UI) compared to urea in 2008. Note the differences in legend
scales among maps for each N treatment. Numbers along contour lines are elevation
in feet above sea level.
UTILITY OF POLYMER-COATED UREA AS A FALL-APPLIED N
FERTILIZER OPTION FOR CORN AND WHEAT
Peter Motavalli                               Kelly Nelson
Associate Professor                                                         Research Agronomist

Convenience, favorable soil conditions at the time of application, reduced equipment and labor
demand, lower cost of nitrogen (N) fertilizer, and the ability to plant earlier in the spring
following fall-applied N applications has favored fall-applied N in Missouri. Fall-applied N is
particularly useful in conditions that limit nitrification especially in fine- to medium-textured
soils (Bundy, 1986). However, fertilizer applications in the fall may increase risk of leaching
under certain soil and weather conditions. Best management practices based on economic
returns and N loss via subsurface drainage included fall N with nitrapyrin (N-serve), spring
preplant and split applications of anhydrous ammonia in Minnesota (Randall et al., 2003a,
2003b). However, claypan soils in Missouri have relatively lower N leaching losses due to poor
drainage through the subsoil clay layer. Farmers and custom applicators utilize weather stations
that report soil temperatures at the 6 in. depth to time fall-applied anhydrous ammonia.
Recently, supply of anhydrous ammonia for fall application has been limited to prepaid
customers and regulations on anhydrous ammonia and ammonium nitrate may further affect
availability of these N fertilizer sources. Alternatives for fall-applied N fertilizer need to be
evaluated for their effects on corn and wheat performance to determine if they are cost-effective.

In two years of corn research, polymer coated urea (PCU) that was fall surface-applied for no-till
corn had grain yields similar to anhydrous ammonia, but surface-applied PCU in the fall or as
early preplant had lower returns than anhydrous ammonia (Nelson and Motavalli, 2007b).
However, deep placement of fall-applied PCU increased yield 16 bu/acre more than deep banded
urea, 28 bu/acre greater than broadcast applied PCU, and 8 bu/acre greater than anhydrous
ammonia (Randall, personal communication). Nitrogen release in Missouri over the winter was
less than 30% for fall applied PCU applications and there was more consistent N release when
PCU was deep banded than when surface applied (Nelson and Motavalli, 2007b). Reduced
efficiency of surface applied PCU may be due to denitrification losses over the winter months
during freeze-thaw events. Deep banding PCU should improve efficiency and make it a cost-
effective alternative to applying anhydrous ammonia. In Minnesota, soil temperatures freeze and
remain frozen; however, no field research has evaluated corn response to deep banded PCU in
Missouri in soils that go through several freeze-thaw cycles as an alternative to anhydrous
ammonia. No research has evaluated fall strip tillage and N fertilizer management systems in
Missouri. Finally, no research has compared deep banded PCU with anhydrous ammonia plus
N-serve.

Wheat research in MO has evaluated application timings (Medeiros et al., 2005) and fall
compared to split applications of PCU (Nelson and Motavalli, 2007a). Applications of PCU later
than February resulted in grain yields less than other N sources (Medeiros et al., 2005). In four
years of research, fall-applied PCU had the greatest N uptake and grain yields when compared to
fall-applied urea alone (Nelson and Motavalli, 2007a). No research has evaluated fall
application timings of PCU compared with other N sources to determine if a single fall
application at the time of planting wheat or later had yields similar or greater than standard
applications of ammonium nitrate. A single fall application would save farmers application cost
of a split application in the fall and spring. Spring applications of N on wheat are usually
challenging due to wet conditions and risk of N loss. In addition, research is needed to evaluate
the response of wheat to blends of urea and PCU.

The objectives of this research are to: 1) evaluate yield response of fall-applied PCU compared
with non-coated urea and anhydrous ammonia with and without N-serve for corn and 2) evaluate
the effect of fall-applied timings of PCU and blends of PCU with non-coated urea (NCU) on
wheat yields when compared to non-coated urea and ammonium nitrate.

Materials and Methods:
Corn. Two field trials with three replications at each trial were established at the Greenley
Research Center in plots 10 by 70 ft. One trial followed soybean residue and the other followed
red clover residue that was frost-seeded into wheat the previous year. Treatments included PCU
and non-coated urea (NCU) at 125 lbs N/acre broadcast surface applied and deep banded using a
Yetter® 2984 strip-till system equipped with high residue Maverick® units with a rolling basket
and dry fertilizer application tubes. A Gandy Orbit Air ground drive fertilizer applicator was
used to deliver PCU and NCU for the strip-tilled treatments. Dry fertilizer was placed
approximately 8 inches deep in the strip tilled region. Nitrogen treatments were applied in the
fall, early preplant (approximately 1 month before planting), and prior to planting. A non-treated
and standard anhydrous treatment at 125 lbs N/acre was included as controls. The N application
rate was reduced to determine the most efficient N sources. Fall, early preplant, and preplant
treatments were applied in both studies on 20 November 2007, 7 April 2008, and 5 May 2008,
respectively.

The soybean residue study was planted to ‘DKC63-42’ at 30,000 seeds/acre on 6 May 2008. In
the clover residue study, ‘DKC61-69’ was planted at 30,000 seeds/acre on 29 May 2008. The
planting date in the clover residue study was delayed 24 days after the preplant fertilizer
application due to wet conditions in the heavy clover residue. The planter was equipped with
Shark-tooth® residue cleaners used in tandem with a no-till coulter. The residue cleaners
performed well in heavy residue of the no-till plots and provided a smooth seedbed above in
strip-tilled plots. Grain yields were determined and grain collected to evaluate for starch,
protein, and oil concentration. Grain moisture was adjusted to 15% prior to analysis. A gross
margin will be calculated for each treatment to compare relative returns of fall compared with
preplant treatments at the conclusion of the experiment.

Wheat. Research was conducted at the Greenley Research Center near Novelty, MO from fall,
2007 to summer, 2008. This research was arranged as a randomized complete block design with
five replications in 10 by 30 ft plots. ‘Pioneer 25R56’ was no-till drilled following an
application of 10-60-140 (N-P-K) on 5 October 2007 at 120 lbs/acre in 7.5 in. rows. Research
was a factorial arrangement of N source and rate (PCU at 75 and 100 lbs N/a, urea at 75 and 100
lbs N/a, and ammonium nitrate at 75 and 100 lbs N/a, PCU 75%:urea 25% at 75 and 100 lbs N/a,
and PCU 50%:urea 50% at 75 and 100 lbs N/a), and application timing (October, November,
December, January, February, March, April). Polymer coated urea (PCU, ESN, Agrium), non-
coated urea (NCU, fast release), 75:25 PCU:NCU, and 50:50 PCU:NCU fertilizer treatments
were applied at 75 and 100 lbs N/acre on 5 October 2007, 17 November 2007, 14 December
2007, 16 January 2008, 13 February 2008, 12 March 2008, and 14 April 2008. Fertilizer release
was monitored using mesh bags placed on the soil surface and soybean stubble placed over the
top of the bags to simulate a fertilizer application. Mesh bags were removed at each application
date and stored in a freezer. Fertilizer samples were washed in water, dried, weighed, and
release was calculated based on the remaining fertilizer. Field plots were harvested with a small-
plot combine. Grain moisture was adjusted to 13% prior to analysis. All data were subjected to
analysis of variance and means separated using Fisher’s Protected LSD (P=0.05).

Results:
The first of a three-year field trial was conducted with extremely wet soil conditions throughout
the growing season in 2008. This provided a worst-case scenario for N fertilizer loss and an
opportunity to evaluate fertilizer sources and strip tillage under extremely challenging weather
conditions.

Corn following soybean residue. The strip-tilled bands could have been planted 3 to 4 days
before the no-till plots (personal observation). Winter annual weeds are common in long-term
no-till fields. Henbit was the primary winter annual weed present in this field (20-40/ft2).
Henbit plants were harvested prior to a burndown herbicide application due to visual differences
in weed growth between treatments. Henbit dry weights were 60 to 70% greater when PCU or
NCU was broadcast applied compared to anhydrous ammonia or a strip-till band application of
PCU or NCU (data not presented). Corn grain yield was ranked anhydrous ammonia =
anhydrous ammonia plus N-serve = NCU strip-till > PCU strip-till > PCU broadcast = NCU
broadcast (P=0.0001).

Corn following clover residue. Extremely wet conditions delayed planting 24 days after the
preplant application timing. Soil moisture was high throughout the spring, 2008. The strip-till
bands dried out before the no-till plots. Corn grain yield when averaged over application timing
was ranked anhydrous ammonia = anhydrous ammonia plus N-serve = NCU strip-till = PCU
strip-till > PCU broadcast > NCU broadcast (P=0.0001). There was no difference between PCU
and NCU grain yields when strip tillage was utilized; however, corn grain yield was greater with
PCU when fall and preplant applied when compared to NCU. Clover dry weights were
approximately 20 to 25% greater when PCU or NCU was broadcast applied compared to
anhydrous ammonia or strip-till band applied PCU or NCU (data not presented). No-till,
broadcast urea had the greatest clover dry weights prior to a burndown herbicide application, and
the lowest corn population (22,800 plants/acre) when compared to strip-tillage (24,200
plants/acre) at harvest. Strip-till application of PCU and NCU had grain yields similar to
anhydrous ammonia at all of the application timings.

Wheat. Rainfall and distribution of rainfall events were extensive in the fall, 2007 and spring,
2008. Less than 20% of the PCU applied in October, 2007 was released by February, 2008
(Figure 3). Fertilizer released from the PCU applied from October, 2007 to February, 2008 was
nearly 50% or greater by 15 June 2008. Less than 35% of the fertilizer was released when
applied from 12 March to 15 June 2008. This indicates that residual fertilizer may be present
from PCU applications in wheat. Application of PCU after 12 March required the presence of a
fast release fertilizer source when applied at 100 lbs N/acre.
The non-treated check grain yield was 53 bu/acre. There was a significant grain yield response
to all N treatments (Figures 4A and B). Grain yields at 100 lbs N/acre averaged 5 bu/a greater
than 75 lbs N/acre (data not presented). Wheat yield was ranked PCU = 75:25 PCU:NCU >
50:50 PCU:NCU > NCU = ammonium nitrate for the October, November, December, January,
February and March application timings (Figure 4B). However, the April 14 application timing
resulted in grain yield rankings of ammonium nitrate = 50:50 PCU:NCU = NCU > 75:25
PCU:NCU > PCU (Figure 4B). Icy conditions at the December application timing and frozen
conditions at the February application timing were the primary environmental conditions that
may have contributed to lower yields for these application timings. In general, there was a rate
response to decreasing amounts of PCU as a ratio of the N fertilizer source for the October,
January, and February application timings. PCU increased average grain yields 6 bu/acre when
compared to NCU for the October to February application timings; however, PCU applications
in mid-March and April were 4 bu/acre less than NCU. PCU applications in Northeast Missouri
from mid-March and later should increase the amount of NCU in the blend to maintain
maximum grain yields based on our results in 2008. Grain yields prior to mid-March were more
variable in the NCU and ammonium nitrate treated wheat when compared to PCU or blends of
NCU with PCU. Fall applications of PCU or a blend of PCU:NCU at 75:25 had yields similar to
or greater than spring applied N in 2008.

Summary:
Corn
   x In an extremely wet year, fall applied urea should be deep banded to improve crop
       performance.
   x PCU and NCU were more effective when deep banded when compared to a surface
       broadcast application in 2008.
   x Broadcast PCU increased yield compared to broadcast NCU following clover residue in
       2008.
Wheat
   x Fall applied PCU is an option for wheat production in upstate Missouri.
   x A ratio of fast release N fertilizer with PCU is recommended for applications after
       February. A 50:50 ratio of PCU:NCU or 100% NCU would be more cost-effective for
       March and April N fertilizer applications.

References:
Bundy, L.G. 1986. Timing nitrogen applications to maximize fertilizer efficiency and crop
  response in conventional corn production. J. Fertilizer Issues. 3:99-106.
Medeiros, J.A.S., P. Scharf, and L. Mueller. 2005. Making urea work in no-till. Abstr. Am.
  Soc. Agron. Madison, WI. [non-paginated CD-ROM].
Motavalli, P.P., K.A. Nelson, S.A. Anderson, and 2005. Variable source application of polymer
  coated urea. Abstr. Am. Soc. Agron. Madison, WI. [non-paginated CD-ROM].
Nelson, K.A. and P.P. Motavalli. 2007. Fall applied polymer coated urea for wheat. Abstr. Am.
  Soc. Agron. Madison, WI. [non-paginated CD-ROM].
Nelson, K.A. and P.P. Motavalli. 2007. Nitrogen management using reduced rates of polymer
  coated urea in corn. Greenley Research Center Field Day Report. pp. 43-48.
NRCS. 2005. Conservation Security Program Watersheds FY-2005.
  http://www.nrcs.usda.gov/programs/csp/2005_CSP_WS/index.html. Accessed 7 December
  2005.
Randall, G.W., J.A. Vetsch, and J.R. Huffman. 2003a. Corn production on a subsurface-drained
  mollisol as affected by time of nitrogen application and nitrapyrin. Agron. J. 95:1213-1219.
Randall, G.W., J.A. Vetsch, and J.R. Huffman. 2003b. Nitrate losses in subsurface drainage
  from a corn-soybean rotation as affected by time of nitrogen application and use of nitrapyrin.
  J. Environ. Qual. 32:1764-1772.




Figure 1. Corn grain yield response to N fertilizer sources applied in the fall, early preplant, and
preplant following soybean residue in 2008. LSD (P<0.05) was 25 bu/acre.
Figure 2. Corn grain yield response to N fertilizer sources applied in the fall, early preplant, and
preplant following clover residue in 2008. LSD (P<0.05) was 40 bu/acre.
Figure 3. Polymer-coated urea (PCU, ESN) fertilizer release for individual application dates.
The LSD (P<0.05) was 5.
Figure 4. The effect of polymer-coated urea (PCU, ESN), non-coated urea (NCU), ammonium
nitrate, 75:25 PCU:NCU, and 50:50 PCU:NCU application timings and ratios at 75 (A) and 100
(B) lbs N/acre on wheat grain yield in 2008. The non-treated control grain yield was 53 bu/acre.
LSD (P<0.05) was 4 bu/acre.
THE IMPACT OF FERTILIZER SOURCE AND TILLAGE SYSTEMS ON
NITROUS OXIDE EMISSIONS
Patrick Nash                               Peter Motavalli
Graduate Student                                                                 Associate Professor
                                                                                     Kelly Nelson
                                                                               Research Agronomist
Background:
Nitrous oxide (N2O) is a greenhouse gas that is a very small portion of the nitrogen cycle, but is
environmentally damaging at low levels. In the lower atmosphere, N2O absorbs infrared
radiation in spectra not absorbed by other common greenhouse gases, such as carbon dioxide.
Because of N2O’s unique spectral absorption range, each molecule absorbs 200 times as much
outgoing radiation as carbon dioxide (Fields, 2004). Besides the large strength in absorption,
N2O has a low reactivity in the troposphere which makes it the longest lived greenhouse gas in
the atmosphere.

Once N2O enters the upper atmosphere, it becomes extremely reactive with ozone molecules
which results in ozone depletion. In a process called photolysis, ultra violet light hits N2O,
producing nitric oxide (NO) which acts as a catalyst in the break down of ozone. Reduction in
ozone allows for higher levels of ultra violet light reaching the earth’s surface which has been
linked to increased skin cancer rates. A report by Kane (1998) found that decreased ozone levels
had increased ultra violet radiation reaching the surface by 10-20% which has been linked to the
20-40% rise in skin cancer since the 1970’s. All of N2O’s environmental impacts make lowering
N2O emissions extremely important to manage climate change.
Nitrous oxide is naturally produced by nitrification and denitrification of soil nitrogen. Increased
rates of N2O emitted from agricultural soils has been attributed to applications of nitrogen
fertilizers and increased potential for denitrification of some soil types. Agricultural fields high
in clay content typically have poor drainage which can result in a large percentage of nitrogen
loss by denitrification. Improving nitrogen use efficiency (NUE) in agricultural production on
poorly drained soils will help reduce N2O emissions by limiting the amount of nitrogen available
for denitrification. During the period of 1980-2000, the NUE in corn production in the US
increased by 36%; however, average NUE of fertilizers in 2000 was still 30-50% of the applied
nitrogen fertilizer (Tilman, 2002).

Recent advances in fertilizer technology have produced enhanced urea fertilizer products which
are polymer coated. Polymer-coated urea (PCU) reduces potential nitrogen loss by controlling
the amount of urea available for microbial activity throughout the growing season. Release rates
from PCU are related to soil temperature and moisture content; however, continued research is
required to fully understand PCU’s effect on nitrogen availability throughout the growing
season. Merchan-Paniagua (2004) observed reduced soil N2O emissions when comparing urea
and PCU plots on claypan soils but did not have the same results in 2005. This could be due to
climatic variation since urea’s release rate from a prill is directly related to soil temperature and
moisture.
Tillage operations in agricultural practices have a strong effect on NUE since fertilizer placement
options are dictated by the tillage system used. No-till practices allow for minimal soil
disturbance and have been shown to increase carbon sequestration and sustain or increase soil
fertility. However, no-till practices require fertilizers to be surface-applied or banded.
Broadcasting urea-based fertilizers greatly increases the potential for volatilization,
immobilization of nitrogen in surface residues, and higher rates of denitrification. Many studies
have suggested that no-till operations will increase soil N2O emissions due to lower oxygen
levels, increased bulk density and soil moisture content. Increased N2O emissions from no-till
operations could potentially offset the increased rates of carbon sequestration which decreases
the global warming benefits associated with no-till.
Strip-till operations cause less soil disturbance than conventional tillage practices and allow the
placement of fertilizers at depth in the soil profile. Incorporation of urea-based fertilizers within
the soil profile can minimize volatilization and lower rates of denitrification. Lower bulk density
and improved drainage should increase soil oxygen levels and reduce soil moisture content.
These properties in theory would reduce N2O emissions, however, many studies measuring
differences in N2O emissions between tillage and no-tillage systems have had mixed results.
Higher N2O emissions have been reported in no-till operation compared to conventional tillage
(Mackenzie et al., 1997; Ball et al., 1999; Baggs et al., 2003; Six et al., 2004). While other
studies have found lower or similar soil N2O emissions in no-till compared to conventional
tillage (Robertson et al., 2000; Elmi et al., 2003; Grandy et al., 2006). The variation in the results
between these studies is thought to be a product of differences in soil type and climatic
conditions. Expanded research on the impact of tillage operations on N2O emissions for specific
soil types and climates will be required to make better estimates of how tillage practices affect
N2O emissions for specific locations. The objective of this research is to examine the differences
in N2O emissions between fertilizer sources (non-coated urea (NCU) and PCU) combined with
different tillage systems/fertilizer placement (no-till/broadcast and strip-till/placed at depth in
soil).
Experimental Design:
The location for this ongoing research is at Greenley Memorial Research Center in Northeast
Missouri on corn plots containing soybean residue from previous season. Nitrogen fertilizer
application on these plots occurred in April (preplant) at a rate of 125 lbs N/acre. Treatments
were arranged in a randomized complete block design with three replications. The treatments
consisted of no-till + broadcast NCU, strip-till + NCU placed at depth, no-till/broadcast PCU,
strip-till+ PCU placed at depth, non-treated/broadcast, and non-treated/strip-till. Gas samples
were taken by replication and two N2O subsamples for each treatment in a replicate. Samples
were taken approximately every other day, but sampling increased directly after rainfall events.
For each gas sample, soil temperatures were recorded and soil samples were taken for
determining soil moisture and nitrate content in order to correlate soil temperature, nitrate
concentration, and moisture with N2O flux.

Research Objectives:
   y Measure differences in N2O emissions between polymer and non-coated urea combined
      with no-till and strip-till management.
   y Obtain N2O emissions that contribute to nitrogen loss.
   y Gain a better understanding of soil temperature and moisture correlation to N2O emission
     and the time period N2O is produced after fertilizer application.
   y Provide information which will help reduce N2O emissions on claypan soil through
     optimal management practices.

2009 Preliminary Results:
Significant N2O emissions did not occur until three weeks after the April 23rd fertilizer
application (Figure 1). No-till, broadcast treatments had higher N2O emissions compared to strip-
till. Strip-till treatments had lower N2O emissions presumably due to lower soil moisture and
nitrate concentration throughout the growing season which reduced denitrification. However,
analysis of soil samples for moisture and nitrate concentration will be required to confirm this
conclusion. There is no apparent difference in N2O emissions comparing PCU and NCU
treatments. Since application, no-till treatments have averaged 0.1080 lbs N2O loss/acre/day and
strip-till treatments have averaged 0.0758 lbs N2O loss/acre/day. It is important to note that the
average daily N2O flux values will be lower as the N2O flux decreases due to less available soil
nitrogen as the current growing season goes on. Previously conducted research in Michigan on
loamy soils less conducive to saturated conditions, denitification, and N2O emissions than
claypan soils found conventional tillage over two full growing seasons averaged 0.0032 lbs N2O
loss/acre/day, while no-till averaged 0.0029 lbs N2O loss/acre/day (Grandy, 2006).




Figure 1. Cumulative N2O emissions for preplant applied polymer (PCU) and non-coated (NCU)
urea from April 23 to June 16, 2009.
References:
Baggs, E.M., M. Stevenson, M. Pihlatie, A. Regar, H. Cook, and G. Cadisch. 2003. Nitrous
         oxide emissions following application of residues and fertilizer under zero and
         conventional tillage. Plant Soil 254:361-370.
Ball, B.C., A. Scott, and J.P. Parker. 1999. Field N2O, CO2, and CH4 fluxes in relation to tillage,
         compaction, and soil quality in Scotland. Soil Tillage Res. 53:29-39.
Elmi, A.A., C. Madramootoo, C. Hamel, and A. Liu. 2003. Denitrification and nitrous oxide to
         nitrous oxide plus dinitrogen ratios in the soil profile under three tillage systems. Biol.
         Fertil. Soils 38:340-348.
Fields, Scott. 2004. Global nitrogen cycling out of control. Environmental Health Perspectives
         112:557-563.
Grandy, A., Terrance Loecke, Sara Parr, and G. Robertson. 2006. Long-term trends in nitrous
         oxide emissions, soil nitrogen, and crop yields of till and no-till cropping systems. J. of
         Environ. Qual. 35:1487-1495.
Kane, R.P. 1998. Ozone depletion, related UVB changes and increased skin cancer incidence.
         Internat. J. Climatology 18:457- 472.
MacKenzie, A.F., M.X. Fan, and F. Cadrin. 1997. Nitrous oxide emission as affected by tillage,
         corn-soybean-alfalfa rotations and nitrogen fertilization. Can. J. of Soil Sci. 77:145-152
Merchan-Paniagua, S. 2006. Use of slow-release N fertilizer to control nitrogen losses due to
         spatial and climatic differences in soil moisture conditions and drainage in claypan soils.
         M.S. thesis, Univ. of Missouri, Columbia, MO
Robertson, G.P., E.A. Paul, and R.R. Harwood. 2000. Greenhouse gases in intensive agriculture:
         Contributions of individual gases to the radiative forcing of the atmosphere. Science
         289:1922-1925.
Six, J., S.M. Ogle, F.J. Breidt, R.T Conant, A.R. Mosier, and K. Paustian. 2004. The potential to
         mitigate global warming with no-tillage management is only realized when practiced in
         the long term. Glob. Change Biol. 10:155-160.
Tilman, D., K. Cassman, P. Matson, and R. Naylor. 2002. Agricultural Sustainability and
         Intensive Production Practices." Nature 418:671-677.
UNIVERSITY OF MISSOURI EXTENSION DIAGNOSTIC LABS
Max Glover
Plant Science Specialist

Samples can be submitted to MU Extension labs through your County Extension office or by
shipping/delivering samples to the lab on the University of Missouri Campus in Columbia,
Missouri. For sampling instructions contact your County Extension office.

Soil Testing Lab – (573) 882-0623 - http://soilplantlab.missouri.edu/soil/
    x Standard soil test - $15

           o Includes pH, Organic Matter, P, K, Calcium, Magnesium, CEC, and plant specific
             recommendations for N, P, K and Lime

           o Plant specific fertilizer and lime recommendations are available for row crops,
             hay, pasture, gardens and orchards

   x   Special soil analyses are available for between $4 and $15 per element or characteristic

   x   Manure nutrient analysis - $22

           o Includes N, P, K, and percent moisture

   x   Compost nutrient analysis - $20

           o Includes N, P, K, Calcium, and Magnesium

   x   Plant tissue nutrient analysis and water suitability analysis are also available

Plant Diagnostic Clinic – (573) 882-3019 - http://soilplantlab.missouri.edu/plant/
   x Plant Disease Identification, Weed Identification, Insect Identification - $15

           o Plant samples or digital photos can be submitted

           o Additional $10 may be needed for lab isolation of fungi, bacteria, or virus

Plant Nematology Lab – (573) 884-9118 - http://soilplantlab.missouri.edu/nematode/
   x Soybean cyst nematode egg count - $15

           o Yield loss of 30 percent is possible without obvious visible symptoms due to high
             SCN infestation

           o SCN yield loss risk is highest in fields planted in continuous soybeans
FOLIAR FERTILIZER AND FUNGICIDE INTERACTIONS ON CORN
Kelly Nelson                                  John Shetley
Research Agronomist                                                                Graduate Student
Peter Motavalli                                                                    Gene Stevens
Associate Professor                                                  Extension Associate Professor
Bruce Burdick                                                                      Laura Sweets
Research Associate/Superintendent                                    Extension Associate Professor

Corn acreage increased over 25% in Missouri and total acreage in the U.S. increased nearly 10
million acres from 2006 to 2007. High yield corn production systems have integrated fungicide
applications to maximize photosynthetic efficiency of the plant. Over the past four years,
median corn yields for 16 site/years increased over 8 bu/acre with a strobilurin fungicide such as
pyraclostrobin (Headline®) (Nelson and Smoot, 2007). The greatest yield increases due to
fungicide applications have occurred in high yield environments.

Fungal infections decrease the area of photosynthetic tissue which reduces the transfer of
assimilates from their source to the ear and diverts assimilates to fungal growth, defense systems,
and increased respiration. Growth stimulation with the strobilurin fungicides has been related to
a reduction in the incidence of disease as well as increased nitrate uptake and assimilation in
small grains (Köhle et al., unpublished). Research has shown that pyraclostrobin was important
in stimulating nitric oxide, a key messenger in plants (Conrath et al., 2004). Increased nitrate
uptake and assimilation following an application of a strobilurin fungicide would justify
additional fertilizer at the time of application. Identifying fertilizer sources that synergistically
increase yield with a fungicide treatment would provide opportunities to manage disease, reduce
application costs, and provide additional fertilizer when crop demand is greatest.

Research has established a link between plant nutrition and disease incidence including the
disease suppressing effects of K, Cl, Mn, B, and P (Fixen et al, 2004). Combining a foliar
fertilizer with a fungicide application may reduce application costs, improve disease suppression
and nutrient response, and increase flexibility in managing crop response to environmental
conditions during the growing season. There was a dramatic increase in the use of strobilurin
fungicides in corn in 2007; however, no research has evaluated interactions between fertilizer
sources and a fungicide treatment. This research will help Missouri farmers make informed
decisions regarding fungicide-fertilizer interactions and how these applications affect
productivity and profitability. No published research has evaluated interactions between
fungicides and foliar fertilizers on corn. No research has been published on the effects of
fungicide treatments on corn plant nutrient levels in the field.

The objective of this research is to evaluate improvements in yield and monitor nutrient uptake
of a foliar fertilizer-fungicide management system for corn.

Materials and Methods:
The first of a two-year field trial was conducted under sprinkler irrigation at Novelty (40.035997
N, 92.243783 W) and Albany (40.251282 N, 94.326977 W) while at Portageville (36.427945 N,
89.700234 W) corn was flood irrigated to assess corn response to fungicide-fertilizer treatments
in high yield environments. The soil was a Putnam silt loam (fine, smectitic, mesic Vertic
Albaqaulfs), Grundy silt loam (fine, montmorillonitic, mesic Aquic Argiudolls), and Tiptonville
sandy loam (fine-silty, mixed, thermic Typic Argiudolls) at Novelty, Albany, and Portageville,
respectively. Field information about the locations and selected management practices is shown
in Table 1.

The study was randomized complete block design with five, four, and three replications at
Novelty, Portageville, and Albany, respectively. Treatments consisted of a factorial arrangement
of foliar fertilizers combined with and without the fungicide pyraclostrobin (Headline®) at 6
oz/acre plus nonionic surfactant at 0.25% v/v applied at VT. Treatments were applied with a
CO2 propelled hand boom at 3 gallons/acre to simulate an aerial application. The following
fertilizer treatments and rates were selected for this research based on previous experience and
locally available foliar fertilizers used on corn in combination with fungicide treatments: 3-18-
18-0 (%N-%P2O5-%K2O-%S) at 2 gal/acre (NA-CHURS/ALPINE Solutions, Marion, OH), 0-0-
30-0 at 2 gal/acre (Double-OK, NA-CHURS/ALPINE Solutions, Marion, OH), potassium
thiosulfate (0-0-25-17) at 1 gal/acre (KTS, Tessenderlo Kerley Inc., Phoenix, AZ), potassium
thiosulfate plus urea triazone (5-0-20-13) at 1.5 gal/acre (Trisert K+, Tessenderlo Kerley Inc.,
Phoenix, AZ), potassium chloride (0-0-62-0) at 2.5 lb/acre (PCS, Potash Corp. of Saskatchewan,
Northbrook, IL), 25-0-0-0 controlled release nitrogen as methylene urea and diurea with less
than 0.01% Cl at 3 gal/acre (CoRoN, Helena Chemical Co., Collierville, TN), 24-0-1-0.6 slow
release N with 0.25% B at 3 gal/acre (Pacer N, Crop Production Services, Galesburg, IL), 22-0-
2-1 with 0.25% B at 1 gal/acre (Task Force Maize, Crop Production Services, Galesburg, IL),
30-0-0-0 at 1 gal/acre (Nitamin, Georgia-Pacific Chemicals, LLC., Atlanta, GA), boron at 2
pt/acre (NA-CHURS/ALPINE Solutions, Marion, OH), Mn-chelate at 2 pt/acre (NA-
CHURS/ALPINE Solutions, Marion, OH), Fe-Mo-Mn-B-Zn (0.3%-0.01%-3.2%-0.2%-2.1%)
premix at 1 qt/acre (MAX-IN, Winfield Solutions, LLC., St. Paul, MN), and 6-0-0-0 with 10%
Ca at 2.5 gal/acre (Nutri-Cal, CSI Chemical Corp., Bondurant, IA

Corn injury from 0 (no visual crop injury) to 100% (complete crop death) was evaluated 7 to 14
days after treatment based on the combined visual effects of N source on necrosis, chlorosis, and
stunting. The incidence of foliar disease was rated on a scale of 0 (no disease) to 100%
(complete infestation) 28 days after treatment. Ear leaf tissue status of the fungicide-treated and
untreated plants was intensively monitored at each location from the time of application until
black layer to build background information to target synergistic foliar nutrient applications.
Analysis of corn ear leaf tissue was monitored 7 days after application for all treatments. Leaf
tissue samples are currently being analyzed.

The center two rows were harvested for yield and moisture converted to 15% prior to analysis.
Grain samples were collected. Grain protein, oil and starch will be determined using NIR
spectroscopy from the Portageville and Novelty sites. Data were subjected to an analysis of
variance and means separated using Fisher’s Protected LSD at P < 0.05. Main effects were
presented in the absence of interactions.

Results:
The incidence of disease was less than 5% at Novelty, Portageville, and Albany in 2008 (Tables
2 and 3). There was a slight reduction in the incidence of grey leaf spot at Albany with
pyraclostrobin, but no other effects due to the fungicide were detected (Table 2). There was a
greater incidence of grey leaf spot when 0-0-30-0 and 0-0-25-17 was applied at Portageville
when compared to the non-treated control. Similarly, 24-0-1-0.6 had a greater incidence of
common rust at Albany when compared to the non-treated control. In general, there were
minimal effects of the fungicide pyraclostrobin or fertilizer treatments on the incidence of
diseases at Novelty, Portageville, or Albany in 2008.

The presence of foliar injury was primarily persistent necrosis of leaf tissue caused by fertilizer
treatments. Injury was less than 10% for all treatments (Tables 4 and 5). Pyraclostrobin alone
did not injure corn (data not presented). Foliar injury increased 0.3 to 0.5% at Novelty and
Portageville with pyraclostrobin, but there was no effect of pyraclostrobin on injury at Albany
(Table 2). Increased injury with pyraclostrobin was probably due to the presence of surfactant
which increased foliar uptake of the fertilizer treatment. Crop injury with 0-0-30-0 ranged from
2 to 7% at all three locations (Table 5). Crop injury was inconsistent with other foliar fertilizers
among locations with less than 10% injury with 0-0-25-17 at Novelty, 5-0-20-13 at Novelty, 6-0-
0-0 at Portageville, and 22-0-2-1 at Albany.

Grain moisture was 0.3 to 0.4% greater when pyraclostrobin was applied when compared to the
non-treated control at Novelty and Albany (Table 4). Fertilizer treatments such as 24-0-1-0.6
and a premix of Fe-Mo-Mn-B-Zn increased grain moisture 0.8 to 1.1% when compared to the
non-treated control at Portageville (Table 5).

Pyraclostrobin increased grain yield 11 bu/acre at Novelty and Portageville in high yield
environments (Table 4). None of the foliar fertilizer treatments increased grain yield when
compared to the non-treated control (Table 5). A reduction in grain yield with 0-0-25-17 at
Novelty and 6-0-0-0 at Portageville was related to foliar injury specific to the fertilizer
treatments. Albany had a lower grain yield potential and grain yields were reduced with 3-18-
18-0, 6-0-0-0, B, and a premix of Fe-Mo-Mn-B-Zn when compared to the non-treated control.
Tissue analysis is currently underway.

Summary:
  x The incidence of disease was less than 5% at all three locations and the effect of
     pyraclostrobin on disease was minimal.
  x The incidence of disease was not affected by fertilizer treatments at Novelty or Albany
     while there was an inconsistent effect of fertilizer treatments on the incidence of disease
     at Portageville.
  x Pyraclostrobin increased grain moisture 0.3 to 0.4% and yield 11 bu/acre when compared
     to the non-treated control at 2 of the 3 sites.
  x There was no significant increase in grain yield when foliar fertilizers were applied to corn
     at VT. Some foliar fertilizers reduced grain yield 14 to 24 bu/acre when compared to the
     non-treated control in 2008.


References:
Conrath, U., G. Amoroso, H. Köhle, and D.F. Sultemeyer. 2004. Non-invasive online detection
    of nitric oxide from plants and other organisms by mass spectroscopy. Plant J. 38:1015-
    1022.
Fixen, P.E., C.S. Snyder, H.F. Reetz, Jr., T. Yamada, and T. S. Murrell. 2004. Nutrient
    management of soybeans with the potential for Asian rust infection. Potash & Phosphate
    Institute, (PPI), Norcross, GA.
Marschner, H. 1995. Functions of mineral nutrients: macronutrients. Mineral nutrition of
    higher plants. pp. 229-312.
Nelson, K.A., P.P. Motavalli, and M.J. Nathan. 2004. The impact of foliar potassium fertilizer
    source on crop response and weed control in a no-till “weed and feed” glyphosate-resistant
    soybean production system. pp. 149-155. Vol. 21. Proceedings of the 2004 Fluid Forum,
    Scottsdale, AZ.
Nelson, K.A. and R.L. Smoot. 2007. Effect of Quadris and Headline on corn grain yields in
    Northeast Missouri. Greenley Research Center Field Day Report. 30:14-16.




Table 1. Field information and selected management practices in 2008.
Field information and management practices       Novelty         Portageville      Albany
Previous crop                                    Corn            Soybean           Soybean
Planting date                                    May 19          May 1             May 21
Fertilizer rate (N-P-K lbs/acre)                 230-70-100 160-0-0                160-60-80
Hybrid                                           DK63-42         P33N58            DK62-43
Seeding rate (seeds/acre)                        35,000          35,000            28,000
Fungicide and foliar fertilizer application date July 23         July 9-10         July 16
   Air temperature (F)                           79              76                89
   Relative humidity (%)                         50              80                70
   Height (inches)                               96              120               120
Harvest date                                     October 10      September 22      November 21
Soil test information
   P (lbs/acre)                                  35              34                62
   K (lbs/acre)                                  288             195               234
   pHs                                           6.0             6.2               5.8
   CEC (meq/100g)                                14.9            9.7               18.8
   Mg (lbs/acre)                                 367             189               696
   Ca (lbs/acre)                                 3601            3052              5235
   OM (%)                                        2.0             1.3               2.6
   Table 2. Incidence of disease at Novelty, Portageville, and Albany 28 days after treatment in
   2008. Data were combined over fertilizer treatments.
Fungicide                   Novelty                             Portageville                           Albany
                       a
Treatment        GLS          CR         NCLB              GLS           ANTH                     GLS            CR
                 --------------------------------------------------- % --------------------------------------------------
Non-treated         1          0.2         0.1              1.2              1                      0.2            2.5
Pyraclostrobinb     1          0.2          0               1.1              1                       0             2.4
LSD (P<0.05)       NS          NS          NS               NS              NS                      0.1            NS
    a
     Abbreviations: ANTH, Anthracnose (Colletotrichum graminicola); CR, common rust (Puccinia sorghi); GLS, grey
    leaf spot (Cercospora zeae-maydis); LSD, least significant difference; NCLB, northern corn leaf blight
    (Exserohilum turcicum); and NS, non-significant.
    b
     Headline at 6 oz/acre plus non-ionic surfactant at 0.25% v/v.

    Table 3. Incidence of disease at Novelty, Portageville, and Albany 28 days after treatment in
    2008. Data were combined over fungicide treatments.
                                     Novelty                         Portageville                     Albany
                        a        b
    Fertilizer treatment    GLS        CR         NCLB              GLS        ANTH                   GLS        CR
                                   ----------------------------------------- % ---------------------------------------
    Non-treated               1        0.3           0               1          1.3                       0      2.3
    3-18-18-0                 1        0.2           0               1           1                        0       3
    0-0-30-0                  1        0.1           0              1.7          1                       0.1 2.4
    22-0-2-1, 0.25% B         1        0.1           0               1           1                       0.3 2.8
    24-0-1-0.6, 0.25% B       1          0          0.1             1.2          1                       0.2 4.2
    25-0-0-0, 0.01% Cl        1        0.6           0               1           1                       0.2 2.4
    0-0-25-17                 1        0.3           0              1.7          1                       0.1 1.6
    5-0-20-13                 1        0.1           0              1.2          1                       0.1 2.4
    0-0-62-0                  1        0.4           0               1           1                       0.1       3
    30-0-0-0                  1        0.2           0               1           1                       0.2 2.5
    6-0-0-0, 10% Ca           1        0.1          0.1              1           1                        0      1.8
    Boron                     1        0.1          0.1             1.2          1                        0      2.1
    Fe-Mo-Mn-B-Zn             1        0.1          0.1              1           1                        0      1.7
    Mn-chelate                1        0.4           0               1           1                        0      2.2
    LSD (P<0.05)             NS        NS           NS              0.3         0.2                      NS 1.7
    a
     3-18-18-0 (%N-%P2O5-%K2O-%S) at 2 gal/acre (NA-CHURS/ALPINE Solutions, Marion, OH), 0-0-30-0 at 2
    gal/acre (Double-OK, NA-CHURS/ALPINE Solutions, Marion, OH), potassium thiosulfate (0-0-25-17) at 1 gal/acre
    (KTS, Tessenderlo Kerley Inc., Phoenix, AZ), potassium thiosulfate plus urea triazone (5-0-20-13) at 1.5 gal/acre
    (Trisert K+, Tessenderlo Kerley Inc., Phoenix, AZ), potassium chloride (0-0-62-0) at 2.5 lb/acre (PCS, Potash Corp.
    of Saskatchewan, Northbrook, IL), 25-0-0-0 controlled release nitrogen as methylene urea and diurea with less than
    0.01% Cl at 3 gal/acre (CoRoN, Helena Chemical Co., Collierville, TN), 24-0-1-0.6 slow release N with 0.25% B at
    3 gal/acre (Pacer N, Crop Production Services, Galesburg, IL), 22-0-2-1 with 0.25% B at 1 gal/acre (Task Force
    Maize, Crop Production Services, Galesburg, IL), 30-0-0-0 at 1 gal/acre (Nitamin, Georgia-Pacific Chemicals,
    LLC., Atlanta, GA), boron at 2 pt/acre (NA-CHURS/ALPINE Solutions, Marion, OH), Mn-chelate at 2 pt/acre (NA-
    CHURS/ALPINE Solutions, Marion, OH), Fe-Mo-Mn-B-Zn (0.3%-0.01%-3.2%-0.2%-2.1%) premix at 1 qt/acre
    (MAX-IN, Winfield Solutions, LLC., St. Paul, MN), and 6-0-0-0 with 10% Ca at 2.5 gal/acre (Nutri-Cal, CSI
    Chemical Corp., Bondurant, IA).
    b
      Abbreviations: ANTH, Anthracnose (Colletotrichum graminicola); Bacterial stalk ; CR, common rust (Puccinia
    sorghi); GLS, grey leaf spot (Cercospora zeae-maydis); LSD, least significant difference; NCLB, northern corn leaf
    blight (Exserohilum turcicum); and NS, non-significant.
      Table 4. Corn injury 7 to 14 days after treatment, grain moisture, and yield as affected by
      pyraclostrobin at Novelty, Portageville, and Albany in 2008. Data were combined over fertilizer
      treatments.
   Fungicide                Novelty                        Portageville                        Albany
   Treatment        Injury Moisture Yield          Injury    Moisture     Yield       Injury Moisture Yield
                      %         %       Bu/a         %          %          Bu/a         %         %   Bu/a
   Non-treated        1.7     19.5      216          1.6       17.1        159          0.5      15.9 143
                 a
   Pyraclostrobin     2.2     19.9      227          1.9       17.2        170          0.5      16.2 143
   LSD (P<0.05)b      0.5      0.2        6          0.2        NS          7          NS         0.2  NS
       a
           Headline at 6 oz/acre plus non-ionic surfactant at 0.25% v/v.
       b
           Abbreviations: LSD, least significant difference; and NS, non-significant.

        Table 5. Corn injury 7 to 14 days after treatment, grain moisture, and yield as affected by
        fertilizer treatments at Novelty, Portageville, and Albany in 2008. Data were combined over
        fungicide treatments.
                                  Novelty                        Portageville                      Albany
                      a
Fertilizer treatment      Injury Moisture Yield          Injury     Moisture Yield         Injury Moisture Yield
                              %           % Bu/a             %             % Bu/a              %         % Bu/a
Non-treated                    0       19.4     222           0         17.0    170             0      16.0 151
3-18-18-0                      0       19.8     226           0         16.9    174             0      16.0 132
0-0-30-0                       7       19.6     211           2         17.6    153             5      16.4 144
22-0-2-1, 0.25% B              0       19.5     226           0         16.9    174             2      16.1 151
24-0-1-0.6, 0.25% B            0       19.8     217           0         18.1    158             0      16.1 152
25-0-0-0, 0.01% Cl             0       19.7     223           0         16.7    167             0      16.4 158
0-0-25-17                     10       19.6     208           0         16.7    171             0      16.2 147
5-0-20-13                      9       19.9     222           0         17.1    182             0      16.0 142
0-0-62-0                       0       19.4     220           0         17.3    164             0      15.9 146
30-0-0-0                       0       19.6     220           0         17.1    168             0      15.8 142
6-0-0-0, 10% Ca                1       19.6     221           1         17.1    149             0      15.9 136
Boron                          0       20.0     234           0         17.1    161             0      16.1 133
Fe-Mo-Mn-B-Zn                  0       19.8     226           0         17.8    159             0      15.9 127
Mn-chelate                     0       19.6     223           0         17.1    161             0      15.9 139
LSD (P<0.05)b                1.3        NS       14         0.5          0.5      19            1       NS   13
       a
        3-18-18-0 (%N-%P2O5-%K2O-%S) at 2 gal/acre (NA-CHURS/ALPINE Solutions, Marion, OH), 0-0-30-0 at 2
       gal/acre (Double-OK, NA-CHURS/ALPINE Solutions, Marion, OH), potassium thiosulfate (0-0-25-17) at 1 gal/acre
       (KTS, Tessenderlo Kerley Inc., Phoenix, AZ), potassium thiosulfate plus urea triazone (5-0-20-13) at 1.5 gal/acre
       (Trisert K+, Tessenderlo Kerley Inc., Phoenix, AZ), potassium chloride (0-0-62-0) at 2.5 lb/acre (PCS, Potash Corp.
       of Saskatchewan, Northbrook, IL), 25-0-0-0 controlled release nitrogen as methylene urea and diurea with less than
       0.01% Cl at 3 gal/acre (CoRoN, Helena Chemical Co., Collierville, TN), 24-0-1-0.6 slow release N with 0.25% B at
       3 gal/acre (Pacer N, Crop Production Services, Galesburg, IL), 22-0-2-1 with 0.25% B at 1 gal/acre (Task Force
       Maize, Crop Production Services, Galesburg, IL), 30-0-0-0 at 1 gal/acre (Nitamin, Georgia-Pacific Chemicals,
       LLC., Atlanta, GA), boron at 2 pt/acre (NA-CHURS/ALPINE Solutions, Marion, OH), Mn-chelate at 2 pt/acre (NA-
       CHURS/ALPINE Solutions, Marion, OH), Fe-Mo-Mn-B-Zn (0.3%-0.01%-3.2%-0.2%-2.1%) premix at 1 qt/acre
       (MAX-IN, Winfield Solutions, LLC., St. Paul, MN), and 6-0-0-0 with 10% Ca at 2.5 gal/acre (Nutri-Cal, CSI
       Chemical Corp., Bondurant, IA).
       b
         Abbreviations: LSD, least significant difference; and NS, non-significant.
EFFECT OF NITAMIN AND HEADLINE ON CORN GRAIN YIELD
Kelly Nelson                               Clint Meinhardt
Research Agronomist                                                              Research Specialist

Introduction:
Corn acreage increased over 25% in Missouri and total acreage in the U.S. increased nearly 10
million acres from 2006 to 2007. High yield corn production systems have integrated fungicide
applications to maximize photosynthetic efficiency of the plant. Over the past four years,
median corn yields for 16 site/years increased over 8 bu/acre with a strobilurin fungicide such as
pyraclostrobin (Headline®) (Nelson and Smoot, 2007). Plant growth stimulation with the
strobilurin fungicides has been related to a reduction in the incidence of disease as well as
increased nitrate uptake and assimilation in small grains (Köhle et al., unpublished). Research
has shown that pyraclostrobin was important in stimulating nitric oxide, a key messenger in
plants (Conrath et al., 2004). Increased nitrate uptake and assimilation following an application
of a strobilurin fungicide would justify additional nitrogen fertilizer at the time of application to
corn. Identifying fertilizer sources that synergistically increase yield with a fungicide treatment
would provide opportunities to manage disease, reduce application costs, and provide additional
fertilizer when crop demand is greatest.

The objective of this research was to evaluate response of corn to Nitamin (Georgia-Pacific
Chemicals, LLC., Atlanta, GA) rates and tank mixtures with Headline.

Materials and Methods:
Field research was conducted Novelty (40.035997 N, 92.243783 W), MO. The soil was a
Putnam silt loam (fine, smectitic, mesic Vertic Albaqaulfs). The study was a randomized
complete block in plots 10 by 40 ft. with four replications. Treatments consisted of a factorial
arrangement of Nitamin (30-0-0) at 0, 0.5, 1, 2, and 4 gal/acre combined with and without the
fungicide pyraclostrobin (Headline®) at 6 oz/acre plus nonionic surfactant at 0.25% v/v applied
at VT. An additional treatment of Headline at 3 oz/acre plus nonionic surfactant at 0.25% v/v
plus Nitamin at 1 gal/acre was included in the study. Field information is shown in Table 1.
Polymer-coated urea (ESN) fertilizer was banded beside each row at 200 lbs N/acre.

Treatments were applied with a CO2 propelled hand boom at 15 gal./acre. Corn plants were
exhibiting some N deficiency from V6 to VT; however, no additional N was applied to evaluate
the benefit of foliar applied N at VT. Corn injury from 0 (no visual crop injury) to 100%
(complete crop death) was evaluated 14 days after treatment based on the combined visual
effects of N source on necrosis, chlorosis, and stunting. The incidence of foliar disease was rated
on a scale of 0 (no disease) to 100% (complete infestation) 28 days after treatment. Plant
greenness was rated on a scale of 0 (brown) to 10 (green) on 28 Sept. The center two rows were
harvested for yield and converted to 15% moisture prior to analysis. Grain samples were
collected. Grain protein, oil and starch will be determined using NIR spectroscopy. Data were
subjected to an analysis of variance and means separated using Fisher’s Protected LSD at P <
0.05.
Results:
Harvested population was similar for all treatments and ranged from 28,200 to 30,200 plants/acre
(Table 1). Crop injury increased 2 to 5% when Headline plus nonionic surfactant was added to
Nitamin at 2 to 4 gal/acre Injury was primarily localized necrosis of leaf tissue (Figures 1 and
2). There was a low incidence of disease and no difference in the incidence of disease was
observed between the non-treated control and Nitamin or Headline treatments. Headline at 60
oz/acre plus Nitamin treated plants were greener two weeks before harvest. Similarly, grain
moisture was 1.6 to 2.4% greater when Headline was applied alone or with Nitamin at 1 to 4
gal./acre when compared to the non-treated control. Grain yield increased 19 and 28 bu/acre
when Nitamin was applied at 2 and 4 gal/acre, respectively (Figure 3). There was no increase in
grain yield when Nitamin was tank mixed with Headline at 6 oz/acre; however, Nitamin at 1
gal./acre tank mixed with Headline at 3 oz/acre increased yield 23 bu/acre. A reduced rate of
Headline (3 oz/acre) and Nitamin (1 gal./acre) had grain yields similar to Nitamin at 2 or 4
gal./acre alone or tank mixed with Headline at 6 oz/acre. In a year with some N deficiency,
Nitamin alone at 2 to 4 gal/acre increased yield while the combination of Headline and Nitamin
was additive only at a reduced rate of both products.

References:
Conrath, U., G. Amoroso, H. Köhle, and D.F. Sultemeyer. 2004. Non-invasive online detection
    of nitric oxide from plants and other organisms by mass spectroscopy. Plant J. 38:1015-
    1022.
Nelson, K.A. and R.L. Smoot. 2007. Effect of Quadris and Headline on corn grain yields in
    Northeast Missouri. Greenley Research Center Field Day Report. 30:14-16.
     Table 1. Field information and selected management practices at Novelty, MO.
Field information and management practices          2008
Previous crop                                       Corn
Tillage                                             No-till
Planting date                                       May 20
Weed control
   Burndown (April 28)                              Roundup PowerMAX 22 oz/acre
   Preemergence (May 23)                            Lumax at 3 qt/acre
Fertilizer rate (N-P-K lbs/acre) N was ESN          200-0-0
Hybrid                                              DK 63-42VT3
   Seeding rate (seeds/acre)                        30,000
Fungicide and foliar fertilizer application date    July 29
   Air temperature (F)                              95
   Relative humidity (%)                            63
   Height (inches)                                  72
Harvest date                                        October 13


Table 2. Plant population, injury, incidence of disease (grey leaf spot and common rust) 28 days
after treatment, greenness (1=brown to 10=green), and grain moisture as affected by Nitamin
(30-0-0) alone and with Headline in 2008.
Treatmenta                   Rate        Population Injury GLS CR Greenness Moisture
                             gal./acre     No./acre        %        %      %        1-10           %
Nitamin                      0              29,200          0      1.5      0           0        19.2
Nitamin                      0.5            29,400          0      1.5      0        1.8         20.4
Nitamin                      1.0            28,300          0      1.0      0        1.0         19.8
Nitamin                      2.0            30,200          0      1.5      0        0.5         19.5
Nitamin                      4.0            29,700          2      1.0      0        0.8         19.6
Headline at 6 oz/acre        0              28,500          0      1.0      0        1.8         20.8
Nitamin                      0.5            30,000          0      1.0      0        2.3         19.9
 + Headline at 6 oz/acre
Nitamin                      1.0            29,300          0      1.0      0        2.0         21.1
 + Headline at 6 oz/acre
Nitamin                      2.0            29,700          2      1.0      0        2.3         21.1
 + Headline at 6 oz/acre
Nitamin                      4.0            28,300          7      1.0      0        2.5         21.3
 + Headline at 6 oz/acre
Nitamin                      1.0            28,200          0      1.0      0        0.8         21.6
 + Headline at 3 oz/acre
LSD (P<0.05)                                    NS          1      NS NS             1.4          1.6
a
 Abbreviations: CR, common rust (Puccinia sorghi); GLS, grey leaf spot (Cercospora zeae-maydis); LSD, least
significant difference; and NS, non-significant.
b
 All Headline treatments were applied with nonionic surfactant at 0.25% v/v.
Figure 1. Corn injury with Nitamin at 2 gal/acre plus Headline at 6 oz/acre plus NIS at 0.25% v/v 14 days
after treatment.




Figure 2. Corn injury closeup with Nitamin at 4 gal/acre plus Headline at 6 oz/acre plus NIS at 0.25% v/v
14 days after treatment.
                      175

                      170

                      165
    Yield (bu/acre)




                      160

                      155

                      150

                      145

                      140
                            0          1             2            3               4               5
                                           Nitamin rate (gal./acre)
                      Nitamin                               Nitamin + Headline at 6 oz/a
                      Nitamin + Headline at 3 oz/a
Figure 3. Grain yield response to Nitamin rates with and without Headline at 6 oz/acre or 3 oz/acre plus
nonionic surfactant at 0.25% v/v. LSD (P<0.05) was 18.
COMPETITION OF VOLUNTEER CORN (ZEA MAYS L.) AND
REMOVAL FROM TRANSGENIC CORN HYBRIDS
Tye C. Shauck                                 Reid J. Smeda
Graduate Research Assistant                                                   Associate Professor


Volunteer corn (Zea mays L.) results from seed dropped due to weather, insect, and disease
induced lodging as well as harvest inefficiencies. The increasing popularity of glyphosate-
resistant (Gly-R) corn results in additional Gly-R volunteer corn as a management problem.
Gly-R volunteer corn is managed easily in Gly-R soybeans (Glycine max) through the
postemergence application of grass selective herbicides such as Fusion, Poast Plus, and Select.

However, there are fewer options to remove volunteer corn from a corn or sorghum crop.
Tillage is one option, but few growers use in-crop tillage due to the time constraints and fuel
costs. In some situations, specific herbicides could be used to remove volunteer corn, provided
there is a difference in selectivity between the volunteer corn and the planted corn. For example,
glufosinate-resistant (Ignite®) and imidazolinone-resistant (Lightning®) corn hybrids could be
planted in a field following glyphosate-resistant corn, and Ignite and Lightning respectively,
applied to remove glyphosate-resistant volunteer corn.

Research is limited on the impact and management of Gly-R volunteer corn in corn. In fact, a
recent study in South Dakota estimated that 3 volunteer corn plants per square yard had limited
effect on corn yield. Research is needed under Missouri field conditions to estimate the impact
of season-long competition of volunteer corn in corn. The objectives of this research were three-
fold: 1) Sample a number of corn fields in central Missouri in the fall following corn harvest to
determine the extent of corn loss due to environmental and mechanical factors; 2) Establish field
trials to determine the potential for Ignite in Liberty-Link® corn and Lightning in Clearfield®
corn to remove glyphosate-resistant volunteer at various growth stages and 3) Determine the
potential impact of volunteer corn to compete season-long with planted corn.

 Field trials were established in Novelty, Missouri in 2008 and 2009. Under no-till conditions,
corn hybrids (population of 69,190 seed per hectare) were sown in 76 cm rows in a randomized
complete block design. Nitrogen, at 168 kg/ha in 2008 and 120 kg/ha in 2009 was broadcasted
at the time of planting. To determine competition effects, Gly-R volunteer corn was planted
randomly with a jab planter at densities ranging from 0 to 8 plants/m², and was allowed to
compete season-long. In a second study with glufosinate-resistant or imadazolinone-resistant
corn, Gly-R volunteer corn was planted randomly in plots to establish densities of 1 and 4
plants/m². Gly-R volunteer corn was treated with Ignite or Lightning when volunteer corn
reached 10, 20, or 40 cm in height.

 In the competition study, a portable meter (SPAD meter) was used to estimate chlorophyll levels
(an indication of leaf nitrogen content). SPAD meter readings decreased for corn at the V8, VT,
and R1 growth stages by 13, 20, and 6%, respectively at 4 volunteer corn plants/m² compared to
the untreated control. However, in 2008 when rainfall amounts were 48 cm greater during the
growing season compared to normal conditions, competition effects resulted in no significant
yield losses due to increasing densities of volunteer corn. In the management study and at both
volunteer corn densities, Ignite resulted in control of ≥ 97, 19, and ≤ 50% at 10, 20, and 40 cm
removal treatments, respectively. Lightning resulted in greater than 80% control of volunteer
corn. Dry weights of volunteer plants were reduced 74 to 99% for treated compared to untreated
plants. For both sets of studies, there was no consistent relationship between the density of
volunteer corn and the timing for removal with reductions in grain yields of planted corn.
Volunteer corn competes with planted corn for available nitrogen, but impacts on grain yield
may be minimal with adequate levels of nitrogen and rainfall. Ignite and Lightning are an
adequate means of volunteer corn removal at early growth stages.
THE EFFECT OF RESIDUAL N FROM CORN ON WHEAT
PRODUCTION
Kelly Nelson                                Peter Motavalli
Research Agronomist                                                            Associate Professor

Objectives & Relevance:
Corn acreage in Missouri has increased while N fertilizer prices have fluctuated dramatically.
Corn production in claypan soils may vary depending on the environmental conditions (Nelson
et al, 2009; Nelson and Smoot, 2008). Nitrogen uptake is affected by water management
systems and fertilizer source (Nelson et al., 2009). In years with low rainfall or other factors
limiting crop growth, residual N from an application to corn may remain in the soil profile
(Nelson et al., 2009) and be susceptible to slow lateral transport (Blevins et al., 1996). Rotation
to a grass crop such as wheat with limited N inputs could reduce fertilizer costs, continue to
maximize N utilization, and minimize N loss when planted after corn. This would shift a typical
crop rotation with wheat from soybean-wheat-corn (Jiang et al., 2007) to soybean-corn-wheat
which may work better for no-till production systems since establishment of corn following
wheat is difficult due to cool, wet soil conditions. Nitrate-N in water samples from suction
lysimeters 153 days after N application to corn of non-coated urea were 85 to 92% lower than
polymer-coated urea (Nelson et al., 2009). This indicated residual fertilizer may be available for
a rotational crop such as wheat. Fertilizer application timing also affects residual N (Nelson and
Motavalli, 2008). No research has evaluated a means to utilize residual N in claypan soils from
different N fertilizer sources and the impact of this change in rotation on crop performance.

The objective of this research is to evaluate the effect of residual N following corn on wheat
grain yield.

Procedures:
   x A two-year rotational crop study utilized current commonly used nitrogen management
      treatments in corn. These plots were then planted to wheat in the fall. This research was
      conducted over a 2-year cycle.
   x The study was arranged as a randomized complete block design with four replications.
      Corn N fertilizer treatments consisted of application timings (fall, preplant, sidedress), N
      sources (anhydrous ammonia, urea, urea plus Agrotain, urea ammonium nitrate, and
      polymer-coated urea) at 150 lbs N/acre, and rates of urea and polymer coated urea (50,
      100, and 150 lbs N/acre).
   x Residual nitrate- and ammonium-N in the soil profile was determined in the fall
      following corn harvest for the anhydrous ammonia, urea, and polymer-coated urea
      treatments when applied at 150 lbs N/acre as well as the non-treated control.
   x Wheat was no-till planted into corn stubble.
   x Wheat grain yield and test weight was determined to evaluate the consistency in crop
      response to residual N following corn.
   x Wheat production challenges following corn will be assessed.
Current status and importance:
Residual N in a corn-soybean rotation has not been shown to enhance soybean production.
Preliminary research in 2008 indicated there was an interaction between N source and
application timing on wheat grain yields the following year (Figure 1). Corn grain yield was not
a good predictor of wheat response. This may be due to the fertilizer source/placement,
application timing, or rate. Wheat grain yield following anhydrous ammonia was similar for the
fall of 2006, preplant in 2007, and a sidedress application in 2007. Side-dress N applications had
wheat grain yields 4 to 20 bu/acre greater than fall and preplant applications in some instances.
This research will help Missouri farmers make informed decisions regarding recommendations
for planting wheat after corn to capture residual N for the wheat crop and minimize
environmental N loss. This research would also help farmers justify soil testing for residual N
for the wheat crop following corn.




Figure 1. Fertilized corn and subsequent non-fertilized wheat grain yields. Corn was planted in
2007 and followed by non-fertilized wheat planted in the fall, 2007. The shaded portion of the
grain yields represents the LSD centered on the non-treated control grain yield. Abbreviations:
AA, anhydrous ammonia; Fall, fall 2006 applied; PCU, polymer-coated urea; Pre, preplant
applied; SD, side-dressed; and UAN, 32% urea ammonium nitrate (Nelson, unpublished).

Expected economic impact of the project:
Farmers need to maximize N utilization by the corn crop. However, environmental conditions
such as drought that limit uptake and use should not hinder the use by a rotational crop such as
wheat. This research will directly impact a farmer’s decision to sample for residual N following
corn and the decision to plant wheat after corn. Utilization of residual nitrogen from corn
increased wheat returns $25 to 125/acre in preliminary research.

References:
Blevins, D.W., D.H. Wilkinson, B.P. Kelly, and S.R. Silva. 1996. Movement of nitrate fertilizer to
glacial till and runoff from a claypan soil. J. Environ. Qual. 25:584-593.

Jiang, P., S.H. Anderson, N.R. Kitchen, E.J. Sadler, and K.A. Sudduth. 2007. Landscape and
conservation management effects on hydraulic properties of a claypan-soil toposequence. Soil Sci. Am. J.
71:803-811.

Nelson, K.A. and P.P. Motavalli. 2008. Cost-effective N management using reduced rates of polymer
coated urea in corn. Missouri Soil Fertility and Fertilizers Research Update. Agron. Misc. Publ. #08-
01:41-50.

Nelson, K.A., S.M. Paniagua, and P.P. Motavalli. 2009. Effect of polymer coated urea, irrigation, and
drainage on nitrogen utilization and yield of corn in a claypan soil. Agron. J. 101:681-687.

Nelson, K.A., and R.L. Smoot. 2009. Twin- and single-row corn production in Northeast Missouri.
Online. Crop Management doi:10.1094/CM-2009-0130-01-RS.
THE IMPORTANCE OF WITHIN-FIELD INOCULUM FROM CORN
DEBRIS IN THE MANAGEMENT OF FUSARIUM HEAD BLIGHT OF
WHEAT
Laura Sweets                             Dr. Gary Berstrom
Extension Associate Professor                                                Principal Investigator
University of Missouri, Cooperator                                              Cornell University


Knowledge of the relative contribution of within-field inoculum sources of Gibberella zeae to
infection of local wheat and barley is important for developing and/or excluding strategies for
managing Fusarium head blight (FHB) or scab of wheat. The experimental objective is to
quantify the relative contribution of within-field corn debris as an inoculum source of Gibberella
zeae for Fusarium head blight and DON contamination in 20 variable wheat or barley
environments over two years, all in regions where corn is the predominant crop in the
agricultural landscape and corn debris is left on the land surface over large areas. The research is
based on the hypothesis that spores of Gibberella zeae that are deposited on wheat spikes and
that result in Fusarium head blight come primarily from well-mixed, atmospheric populations in
an area. Our results should provide a realistic range of estimates for the scab and DON reduction
benefits to be realized by avoiding cereal planting into corn stubble. It will also suggest the
magnitude of FHB/DON reduction to be expected from tillage or other direct debris management
techniques in a single field of wheat or barley within a larger corn production region. Building
on techniques perfected in New York and Virginia in 2007-2008, we will use a marked (AFLP)
isolate, release-recapture experimental approach to assess relative contribution of localized
clonal inocula to infection of cereal heads at the source and at more than 100 feet from the source
in commercial wheat and barley fields otherwise lacking corn or cereal debris. We expect that
concentrated clonal inoculum may overestimate the contribution of local inoculum to FHB and
DON, so we are also employing replicated microplots in each experimental field with naturally
overwintered corn debris collected from sources close to those same wheat and barley fields. The
research will be conducted in two commercial-scale wheat or barley fields per season in Illinois,
Missouri, Nebraska, New York, and Virginia. The Missouri sites are at the Greenley Memorial
Research Center and the Bradford Research Center. All field sites are in regions with
considerable acreage of over-wintered corn residues nearby.

Results from this study will increase our understanding of the spread of G. zeae from a local
source of inoculum and will be of immediate value in determining the relative risk of infection of
wheat by G. zeae from within-field sources of inoculum. Ultimately, our efforts will aid in
developing and/or excluding strategies for managing FHB and will help refine forecasting/risk
assessment models for FHB.
THE EFFECT OF SLOW- AND FAST-RELEASE UREA FERTILIZER
RATIOS AND TIMINGS ON WHEAT GRAIN YIELD
Kelly Nelson                                Peter Motavalli
Research Agronomist                                                          Associate Professor
Clint Meinhardt                                                               Randall Smoot
Research Specialist                                                              Superintendent


Management strategies to reduce soil N loss include improved timing of N fertilizer applications,
better use of soil and plant testing procedures to determine N availability, application of
nitrification or urease inhibitors, and use of N fertilizer sources that are suitable for local
environmental conditions (Dinnes et al., 2002). The use of slow-release nitrogen (N) fertilizer
for wheat may be a cost-effective management practice to increase crop performance and allow
for a single N fertilizer application in the fall.

Research was conducted in Northeast Missouri from 2004 to 2007 determined the impact of
polymer-coated urea (ESN) rates and application timings on wheat grain and frost-seeded clover
forage yields. Grain yields with fall-applied polymer-coated urea (PCU) were similar to a split
application in three of four years and were greater than a split application in one of four years
(Nelson and Motavalli, 2007). Fall-applied polymer-coated urea had grain yields that were 4 to
24 bu/acre greater than non-coated urea in two of the four years. Polymer coated urea release
was related to rainfall throughout the winter months in 2006 and 2007 (Figure 1). Differences in
wheat response were related to variation in soil drainage among years. January and February
PCU applications at Columbia increased grain yield 15 and 10 bu acre-1, respectively, when
compared to urea alone while later application timings reduced yield when compared to urea
alone (Medeiros, 2006). However, heavy rainfall on frozen ground during this time may result in
off-site movement of polymer coated fertilizer sources in transitional, temperate weather zones.
Limited research has examined application timings of polymer coated urea and blend ratio
combinations of polymer-coated urea (slow-release) with non-coated urea (fast-release). The
objective of this research was to determine the impact of polymer-coated urea application
timings and ratios of slow- and fast-release urea on wheat grain yield in Northeast Missouri.

Materials and Methods:
Research was conducted at the Greenley Research Center near Novelty, MO in 2008 and 2009.
This research was arranged as a randomized complete block design with five replications in 10
by 30 ft plots. ‘Pioneer 25R56’ was no-till drilled following an application of 10-60-140 (N-P-
K) on 5 October 2007 and 20-50-100 on 30 October 2008 at 120 lbs/acre in 7.5 in. rows. PCU
release was determined using mesh bags that were deployed on nine different dates and
recovered at subsequent dates, washed in cold water, dried, weighed, and percent release
calculated (Figure 1 and 2). Polymer coated urea (PCU, ESN, Agrium), non-coated urea (NCU,
fast release), 75:25 PCU:NCU, and 50:50 PCU:NCU fertilizer treatments were applied at 75 and
100 lbs N/acre on 7 application dates (Figures 3 and 4) in 2008 and 2009. Plots were harvested
with a small-plot combine. Double-crop soybean, ‘Asgrow 3602’ and ‘Pioneer 94Y01’, was
planted 7 July 2008 and 3 July 2009, respectively, to determine the effect of N management in
wheat on subsequent soybean response. Grain moisture was adjusted to 13% prior to analysis.
All data were subjected to analysis of variance and means separated using Fisher’s Protected
LSD (P=0.05).

Results:
Rainfall and distribution of rainfall events were extensive in the fall and spring of both years.
Over 40% of PCU applied from October to February was released by 15 June 2008 (Figure 1)
and 2009 (Figure 2). Fertilizer release was dependent on application date with up to 80% of
applied fertilizer released by 15 June. The non-treated check grain yield was 53 bu/acre in 2008
and 30 bu/acre in 2009. There was a significant grain yield to response to all N treatments in
2008 and all but 100% PCU applied in April, 2009 (Figures 3 and 4). Grain yields at 100 lbs
N/acre averaged 5 bu/a greater than 75 lbs N/acre in 2008 while there was virtually no difference
between rates in 2009 when averaged over all application timings (data not presented).

Wheat yield was ranked PCU = 75:25 PCU:NCU > 50:50 PCU:NCU > NCU for the October,
November, December, January, February and March application timings (Figure 3). However,
the April 14 application timing resulted in grain yield rankings of 50:50 PCU:NCU = NCU >
75:25 PCU:NCU > PCU. Icy conditions at the December application timing and frozen
conditions at the February application timing probably contributed to lower yields for these
application timings. In general, there was a rate response to decreasing amounts of PCU for the
October, January, and February application timings.

Head scab, Septoria leaf blotch, and common rust was prevalent in 2009 which reduced overall
grain yields and test weight (data not presented). PCU applied at planting was similar or greater
than all application timings of PCU alone which was related to reduced release later in the season
(Figure 4). A mixture of PCU with NCU was required at the April application timing in 2009.

Fall applications of PCU or a blend of PCU:NCU at 75:25 had yields similar to or greater than
spring applied N in 2008 while a 50:50 blend of PCU:NCU had the most consistent yields in
2009. PCU applications in Northeast Missouri from mid-March and later should include a
greater amount of NCU in the blend to maintain maximum grain yields based on our results in
2008 and 2009. Grain yields prior to mid-March were more variable in the NCU treated wheat
when compared to PCU or blends of NCU with PCU.

References:
Dinnes, D.L., D.L. Karlen, D.B. Janes, T.C. Kaspar, J.L. Hatfield, T.S. Colvin, and C.A.
    Cambardella. 2002. Nitrogen management strategies to reduce nitrate leaching in tile-
    drained Midwestern soils. Agron. J. 94:153-171.
Medeiros, J.A.S. 2006. Management alternatives for urea use in corn and wheat production. MS
    Thesis. University of Missouri-Columbia, MO.
Nelson, K.A. and P.P. Motavalli. 2007. Fall-applied polymer-coated urea for wheat. Abstr.
    Am. Soc. Agron. CD-ROM.
Whitney, D.A. and W.B. Gordon. 1998a. Evaluation of polymer-coated urea as a starter
    nitrogen source for wheat. Kansas Fertilizer Research. Report of Progress, 829. pp. 11-12.
Whitney, D.A., W.B. Gordon, and A.J. Schiegel. 2000. Controlled-release nitrogen fertilizer in
    starter for sorghum production. Kansas Fertilizer Research. Report of Progress, 868. pp.
    89-91.
Figure 1. Polymer-coated urea (PCU, ESN) fertilizer release for individual application dates
from fall, 2007 to spring, 2008. The LSD (P<0.05) was 5.
Figure 2. Polymer-coated urea (PCU, ESN) fertilizer release for individual application dates
from fall, 2008 to spring, 2009. The LSD (P<0.05) was 9.
Figure 3. The effect of polymer- (PCU, ESN) and non-coated (NCU) urea application timings
and ratios at 100 lbs N/acre on grain yield in 2008. LSD (p=0.05) was 4 bu/acre.
Figure 4. The effect of polymer- (PCU, ESN) and non-coated (NCU) urea application timings
and ratios at 100 lbs N/acre on grain yield in 2009. LSD (p=0.05) was 11 bu/acre.
NUTRIENT MANAGEMENT IN BIOFUEL CROP PRODUCTION
Tim Reinbott                             Manjula Nathan
Research Associate/Superintendent                                   Extension Associate Professor
Kelly Nelson                                                                   Robert Kremer
Research Agronomist                                                Adjunct Professor USDA-ARS

Introduction:
Corn acreage has increased in Missouri as a result of higher corn prices due in part to ethanol
demand. This has resulted in more corn on corn rotations. There is also considerable interest in
cellulosic ethanol production using corn stover, annual crops such as sorghum, and perennial
grass crops such as switchgrass and miscanthus. Removal of above ground biomass could
adversely result in alterations of soil properties as well as changes in soil fertility
recommendations. This research is designed to answer these questions through a cropping
systems approach.

Concern over higher energy prices as well as environmental issues such as global warming has
increased interest and use of alternative energy sources such as ethanol and biodiesel. The
federal government has issued tax incentives for the production of ethanol and has set goals of
future renewable energy use. The largest source of ethanol has been derived from corn grain and
use has increased rapidly in the past decade with 7.5 billion gallons of ethanol produced using
approximately 20% of the US corn crop in 2007. This trend will continue since more ethanol
plants are coming on line and the federal government set a target in 2005 of 7.5 billion gallons of
ethanol blended by 2012 and in 2007 increased that target to 35 billion gallons by 2017. Other
federal programs have set goals as high as 30% of the gasoline demand to be derived from
cellulosic materials by 2025 (45 billion gallons). To meet this and other goals, sources other
than corn grain must be used since the entire US corn crop can only produce 35 billion gallons of
ethanol. Most analyst put the cap on ethanol derived from corn grain at approximately 14 billion
gallons leaving over 30 billion gallons coming from cellulosic sources. The conversion of corn
stover as well as forage and biomass crops such as switchgrass and miscanthus into ethanol is
necessary to meet this demand.

To meet the demands for biofuel production, farming practices may change from an annual
rotation of corn and soybean to continuous corn production for both grain and stover. The entire
above ground biomass production of annual and perennial crops will also need to be harvested
and removed for cellulosic ethanol production. Removal of the entire above ground biomass can
result in changes in many soil properties through the loss of organic matter and degradation in
the quality of soil structure resulting in a loss of water exchange, aeration, and biological
activity. Cellulosic ethanol production from perennial crops such as switchgrass and miscanthus
may be a better choice than from annual crops such as corn and sorghum since their root systems
are more extensive, may not result in a loss of soil organic matter, and provide more consistent
soil biological activity critical for nutrient cycling.

Current Missouri fertilizer recommendations do not reflect removal of the entire biomass and
will need to be adjusted to meet the demands from these practices. Simple calculations of the
removal of 2/3’s of the corn stover per acre is equal to removal of 10 lb P205/acre and 80 lb
K20/acre with a cost of nearly $70/acre. Utilizing switchgrass as a biofuel has the potential to
take off as much as 45 lb P2O5/acre and 230 lb K2O/acre when dry matter yields are 5 tons/acre/.
These numbers are only estimates and do not reflect data collected in Missouri in replicated
trials. We also do not know if luxury consumption by plants due to a buildup of soil P and K
levels within one year will result in a larger than expected removal of soil nutrients. For
Missouri producers to be competitive with new market opportunities using biofuels, they will
need to know how to manage soil fertility inputs and crop selection.

Objectives and Relevance:
  1. To determine the optimum nutrient management practices for environmentally safe and
      economically viable biofuel production.
  2. To evaluate long-term effects of biofuel crop production on selected chemical, physical
      and microbiological properties of crop land.

Procedures:
   x Experimental plots established for research on biofuel crops production and management
      practices at Research and Extension Centers near Columbia and Novelty will be used to
      conduct research from 2009 to 2011. The experimental design will be 8x3 factorial laid
      out in a split-plot design.
   x The main plots will have 8 bio-fuel cropping systems that were established in 2007 as
      listed below:
           1. Continuous Corn for grain only
           2. Continuous Corn for grain and stover removal
           3. Corn-soybean rotation for grain only
           4. Soybean-corn rotation for grain only
           5. Sweet Sorghum /Wheat double crop
           6. Miscanthus
           7. Switchgrass
           8. Tall Fescue
   x The subplots will receive the following three fertilizer treatments:
                  1. University of Missouri Fertilizer and lime recommendations with a 4 year
                       P and K Buildup
                  2. Fertilizer recommendations based on annual crop removal values with one
                       year P and K buildup
                  3. Control- 0 P, 0K
   x The following soil chemical, physical and microbiological measurements made each
      year.
                  1. Initial Soil fertility measurements (pH, NA, P, K, Ca, Mg, OM, CEC)
                  2. Organic C and total N measurements
                  3. Wet aggregate stability measurements to determine structural changes
                  4. Carbon and Nitrogen mineralization using selected soil enzyme assays
                  5. End of season soil fertility measurements
   x Plant measurements:
                  1. Dry matter production (Treatments 2, 5-8)
                  2. Grain yield (Treatments 1-4)
                  3. Nutrient uptake (based on dry matter production and grain yield)
Economic Impact:
With rising cost of N, P and K fertilizers, efficient use for Missouri farmers is increasingly
important. At the same time, farmers are facing new opportunities to grow and market non-
traditional crops in the biofuel industry which will demand new and adjusted rates of such
fertilizers. The impact of fertilizer management and the impacts on soil properties may have
unforeseen economic impacts since this research will be establishing basic evaluations of these
decisions on soil properties.

References:
    1. Andrews, S. 2006. Crop residue removal for biomass energy production: effects on soils
       and recommendations. White Paper. USDA-Natural Resources and Conservation
       Service.
    2. Fixen, P. 2007. Potential biofuels influence on the fertilizer market. Proceedings of the
       2007 Fluid Fertilizer Forum. Feb 18-20, Scottsdale, AZ.
    3. Kovar, J. 2007. Will sulfur limit bio-fuel corn production? ASA Abstract. ASA-SSSA-
       CSSA
    4. Service, R.F. 2007. Biofuel researchers prepare to reap a new harvest. 2007. Science.
       315: 1488-1491.
    5. Wilhelm. W.W., J.M. F. Johnson, D.L. Karlen, and D.T. Lightle. 2007. Corn stover to
       sustain soil organic carbon further constrains biomass supply. Agon. J. 99:1665-1667.
FIELD CALIBRATION OF WOODRUFF, MEHLICH AND SIKORA
BUFFER TESTS FOR DETERMINING LIME REQUIREMENT FOR
MISSOURI SOILS
Manjula Nathan                           Robert Kallenbach
Extension Associate Professor                                                     Associate Professor
Kelly Nelson                                                                          David Dunn
Research Agronomist                                                      Supervisor Soil Testing Lab
                                                                                     Tim Reinbott
                                                                  Research Associate/Superintendant


In Missouri, the Modified Woodruff Buffer test is used to determine the lime requirement of
soils. Though this method has proven to work for Missouri soils it uses para-nitrophenol as one
of the reagents which is a hazardous substance. Para-nitrophenol can cause serious health effects
on humans when inhaled or when absorbed by skin. Thus the waste produced by the Woodruff
buffer test needs to be treated as a hazardous waste. Also, since Missouri is the only state in the
nation which uses the Woodruff Buffer test, it is better to evaluate the other buffer tests used so
that data and lime recommendations developed for Missouri can be compared with similar
information from the other states.

The SMP buffer test is commonly used throughout the U.S. for determining lime requirement.
This is the method listed as the recommended procedure for lime requirement in the publication:
Recommended Chemical Soil Test Procedures by the North Central Region. This method also
uses para-nitrophenol. Even though the SMP buffer test is commonly used throughout the U.S.
for determining lime requirement, the SMP buffer solution contains potassium chromate, a
carcinogen, and poses a health risk to laboratory technicians who perform this test. Additionally,
all waste generated by the test must be collected for proper disposal. An alternative to the SMP
test is the Sikora Buffer test (Sikora, 2006). Sikora from University of Kentucky developed a
buffer that mimics SMP buffer and this buffer doesn’t have any hazardous chemicals in its
composition.

The University of Missouri fertilizer and lime recommendations are being revised at this time.
Findings from this research will be used in developing lime recommendation based on the buffer
test that best suits for Missouri soils. It will be incorporated into the University Missouri soil test
based lime recommendation used by the MU Soil testing labs. Soil incubation studies have been
completed in evaluating the Woodruff, Mehlich and Sikora buffers and these lime requirement
methods should be field calibrated before the best method can be adopted.

Objectives:
   1. To determine whether the Modified Woodruff Buffer test is accurately predicting the
      lime requirement for Missouri soils.
   2. To calibrate the Modified Woodruff Buffer, Sikora and Mehlich buffer tests for Missouri
      soils.
   3. To Determine the Lime Recommendations Equations for Sikora Buffer and Mehlich
      Buffers for Missouri Soils for the pH rages of 5.5 to 6.0; 6.0 to 6.5 and 6.5 -7.0.
                                                                                              Page 2




   4. Compare the field calibration results with incubation study results in evaluating the buffer
      tests.

Procedures:
   x Field calibration studies will be established at Bradford, Novelty, Southwest, and Delta
      University of Missouri Research and Extension Centers. The Bradford, Novelty, Graves
      sites will have corn-soybean rotations, Southwest farm will have forages and the Delta
      site will have rice-soybean rotations.
   x Each experimental field site will receive five lime treatments (0, 1/3 LR, 2/3 LR, 1 LR
      and 1.5 Lime Recommendations - LR) and three lime buffer test evaluations. The study
      will be a split plot design with main plots receiving the five lime treatments and sub plots
      will be used to estimate LR using different buffer tests. All the plots will receive
      recommended levels of N, P and K.
   x Soil samples will be collected at the beginning of the study at 0-6” and 6”-12” depths to
      measure top soil and subsoil pHs at the beginning of the study, and at the end of each
      growing seasons at the 0-6” depth. Soil samples will be analyzed pHs, Woodruff,
      Mehlich and Sikora buffer pHs.
   x The plant yield data will be correlated with the response received for lime requirement
      estimated by the three different buffer tests and will be compared with the incubation
      studies results.

Current Status and Importance of Research:
Soil acidity is a major factor limiting plant growth throughout North America. About 31% of the
soils tested in North America had soil pH levels lower than 6.0 ( Fixen et. al., 2005). About 26%
of the soils tested by the University of Missouri Soil testing labs for field crops had low pHs (less
than 5.3) and 38% had medium pHs (between 5.3 and 6.0; Nathan, 2005, 2007). Based on soil
test summary for 2006 about 64 % of the soil samples analyzed by the MU soil testing labs had
pHs less than 6.0 and would probably need lime to achieve optimum yields. The Woodruff
buffer test used by the University of Missouri Soil Testing labs contains p-nitrophenol which is
classified as a hazardous waste. Therefore alternative procedures should be considered to
evaluate lime requirement for Missouri soils.

As a first step, Modified Mehlich buffer test was evaluated for determining lime requirement in
Missouri soils. (Nathan, Scharf and Sun, 2005; 2006). The modified Mehlich buffer does not
contain hazardous constituents and has been shown to provide lime recommendations in
Missouri soils as well as the Woodruff buffer (Nathan, Scharf and Sun, 2006; Figure 1).
However, the modified Mehlich buffer has limitations since it can not be stored beyond two
weeks without microbial growth and it does not provide the same buffer pH value as the
Woodruff buffer. Since the use of Modified Mehlich buffer test for commercial soil testing labs
has limitations due to the short shelf life, a buffer is proposed to be developed without hazardous
chemicals that would have a long shelf-life and would mimic the acid-base characteristics of the
Woodruff buffer. Developing a buffer without hazardous chemicals producing the same pH as
Woodruff buffer would eliminate hazardous waste and have no effect on agronomic
interpretations.
                                                                                        Page 3




Figure 1: Relationship between Woodruff and Mehlich buffer pH


                         8.00

                                    MpH = 0.993WpH - 0.420
                         7.50       R2 = 0.916 N = 796
   Buffer pH (Mehlich)




                         7.00


                         6.50


                         6.00


                         5.50


                         5.00
                             6.00   6.50      7.00       7.50       8.00
                                           Woodruff pH




Figure 2: Relationship between Woodruff and Sikora buffer pH


                         8.00




                         7.50
   Buffer pH (Sikora)




                         7.00




                         6.50              SpH = 1.168WpH - 0.930
                                           R2 = 0.865 N = 769

                         6.00
                             6.00   6.50      7.00       7.50       8.00
                                           Woodruff pH




Sikora (2006) developed a new buffer named Sikora buffer to mimic the SMP buffer which is
currently used by the University of Kentucky soil testing labs. Laboski, Peters and Repking
(2006) evaluated Sikora buffer and modified Mehlich buffers as alternative to SMP buffer in
Wisconsin and found the Sikora and Mehlich buffer to perform better than SMP buffer in
determining lime requirement in Wisconsin soils. However, due to the short bench life of
                                                                                                 Page 4




Mehlich buffer they chose Sikora buffer to be a better indicator for lime requirement in
Wisconsin soils.

Incubation study was conducted in Missouri by Nathan and Sun (2008) in comparing Sikora
Buffer to Woodruff Buffer for Missouri soils had promising results (Fig 2). The Sikora buffer
was found to be well correlated with the Woodruff Buffer suggesting this buffer could be used as
an alternative to Woodruff buffer. However, Sikora buffer should be calibrated using lab
incubation with CaCO3 to come up with the lime recommendation equations for use of this
buffer to Missouri soils.

Field calibrations are required before these buffer tests can be validated for Missouri Soils.
Godsey et al., 2007 evaluated common lime requirement methods for Kansas soils by comparing
SMP, Mehlich and Ca(OH)2 direct titrations using lab incubations, greenhouse and field
calibrations. They found in their comparison of the lime requirement from 60-days incubations
with field observed lime response, the actual lime requirement in the field was greater than
predicted by the 60-days incubations. Several researchers have compared the different lime
requirement buffer methods to see which buffer predicts the lime requirement more accurately.
Results from their studies have been mixed and found to be largely dependent on soil texture and
organic matter content. These emphasize the need for field calibrations of the buffer tests before
validating the best buffer test to evaluate the lime requirement for Missouri soils.

Economic Impact:
Accurate and relevant lime recommendations are critical for economical use of fertilizers
recommendations. This research will further our ability to use lime efficiently. Adoption of the
Sikora as an alternative to Woodruff buffer for Missouri soils will have the following benefits:
Sikora buffer doesn’t have any hazardous chemicals and thus it will be safe for the lab personnel
to use without health hazards. By calibrating and adopting this buffer test, the major problem of
hazardous waste disposal by the soil testing labs waste will be eliminated. When calibrated for
Missouri soils for determining lime recommendations, this buffer test will save over thousands of
dollars over the years on money spent on hazardous waste disposal. Missouri is the only state
that uses Woodruff buffer for lime determinations. Since Sikora buffer mimics SMP buffer, the
lime recommendations from Missouri could be directly compared with many other state’s
recommendations.


References:
   1. Fixen, P.E., Bruulsema, T.W., Johnson, A. M., Mikkelsen, R. I., Murrell, T. S., Snyder, C. S., and
       W. M. Stewart. 2005. Soil Test Levels in North America, 2005. Summary Update.
       PPI/PPIC/FAR Technical Bulletin 2005-1.

    2. Godsey, C. B., Pierzynski, G. M., Mengel, D. B., and R. E. Lamond. 2007. Evaluation of
       Common Lime Requirement Methods. Soil Sci. Soc. Am. J. 71:843-850.

    3. Laboski, C., Peters, J., and M. Repking. 2006. Alternative Buffers to the SMP for Lime
       Recommendations. Dept. of Science. University of Wisconsin- Madison.

    4. Nathan, M., Stecker, J., and Y. Sun. 2004. Soil Testing Guide. University of Missouri Soil &
       Plant Testing Laboratory Publication. (Electronic Publication)
                                                                                             Page 5




5. Nathan, M. V., Scharf, P., and Y. Sun. 2006. Evaluation of Mehlich Buffer as an Alternative to
   the Woodruff Buffer for Lime Recommendations in Missouri. ASA, SSSA, CSSA Madison, WI.

6. Nathan, M., Scharf, P. and Y. Sun. 2006.Comparison of Woodruff Buffer and Modified Mehlich
   buffer Tests for Determining Lime requirement in Missouri Soils. In: Missouri soil Fertility and
   Fertilizers Research Update 2005. Agronomy Miscellaneous Publ. #06-01, College of agriculture,
   Food and Natural Resources, University of Missouri. P 109-113.

7. Nathan, M and Y. Sun. 2007. Preliminary evaluation of Sikora Buffer to determine lime
   requirement in Missouri Soils.

8. Sikora, F. J. 2006. A buffer that mimics the SMP buffer for determining lime requirement of Soil.
   SSSAJ 70: 474-486.
2009 MISSOURI VARIETY TESTING PROGRAM
Bill Wiebold                                                                  Howard Mason
Professor                                                                     Research Associate
Delbert Knerr                                                                 Richard Hasty
Research Specialist                                                          Research Specialist
David Schwab                                                                  Jeremy Angotti
Research Specialist                                                          Research Specialist
                                                                                    Bill Schelp
                                                                             Research Specialist



The University of Missouri Variety Testing program provides an unbiased yield comparison of
corn, grain sorghum, and soybean varieties grown in the state. These varieties are tested at
multiple locations in Missouri where the crops are widely grown. Data are collected and
compared within four regions: north, central, southwest and southeast Missouri. The MU Variety
Testing program is completely self-sufficient and is funded by fees charged to companies that
enter varieties into the various tests. Yield comparisons are published in the Crop Performance
Reports available at your local extension office or can be viewed on the World Wide Web at:
www.varietytesting.missouri.edu.

The Greenley Memorial Center is one of the north region sites for corn, grain sorghum, and
soybean variety testing. In 2009, 144 corn hybrids are entered into the non-irrigated corn test
here at Novelty, there are 11 grain sorghum hybrids tested here, and 100 group III glyphosate
resistant soybean lines, 36 group IV glyphosate resistant soybean lines, and 30 non-glyphosate
resistant soybean lines evaluated here.

For additional information:
Call 573-882-2307.
Email us at: www.varietytesting@missouri.edu.
View our web site at: www.varietytesting.missouri.edu.
NORTH MISSOURI SOYBEAN BREEDING
David Sleper                                                                       Kerry Clark
Professor                                                                     Research Associate


The University of Missouri-Columbia has a northern soybean breeding and variety development
program that works with non-GMO soybeans in the mid 3 to mid 4 maturity range. The main
emphasis of variety development at MU is and increasing protein levels in elite soybean varieties
and improving soybean cyst nematode (SCN) resistance by diversifying the genetic basis for
resistance. The program also breeds for food type soybeans such as natto, tofu and edamame, and
works in fatty acid modification, including lower linolenic acid levels. Varieties released by MU
may be available through Missouri Crop Improvement Association (MCIA) members or as
branded lines. MCIA and MU both have several lines entered into the state variety trials this
year. Each of these is being grown in a strip plot at the Greenley Research Center in 2009. The
public is welcome to observe these varieties.

MPG 415CN is a conventional early-mid group IV indeterminate variety (relative maturity 4.3)
that averages 39” in height. It has white flowers, tawny pubescence and black hila seed. MPG
415CN is resistant to races 3and 14 of soybean cyst nematode (SCN) and is moderately
susceptible to sudden death syndrome (SDS). MPG 415CN has demonstrated significant yield
advantages over the variety Maverick in both SCN infested and non-infested environments. This
line was entered into the 2008 State Variety Trials.
        Quality Assurance Class
        Davis Seed Farms, Inc. Vandalia, MO (573) 594-3222
        Vandiver Seed Company Orrick, MO (816) 519-3341

MAVERICK is a late group III indeterminate variety (relative maturity 3.8) that averages 41” in
height. It has purple flowers, grey pubescence, brown pods and buff hila seed. Maverick is
resistant to race 3 and moderately resistant to race 14 of soybean cyst nematode. It also possesses
the Rps1k gene for resistance to Phytophthora Root Rot.
        Foundation Class
        Missouri Foundation Seeds Columbia, MO (573) 884-7333
        Certified Class
        Davis Seed Farms, Inc. Vandalia, MO (573) 594-3222

WOOSTER is available through the Missouri Crop Improvement Association and was
developed by the USDA in Ohio. It is a non-GMO line with 3.9 relative maturity. It has good
SCN tolerance and yields well in both infested and non-infested locations and has some
phytophthora resistance. It has purple flowers, light tawny pubescence, tan pods and black hila.

MAGELLAN is an older variety that has continued to do well in yield trials. It is a conventional
line with a relative maturity of 4.3. Magellan has purple flowers, grey pubescence, tan pods and
buff hila. It averages 42” in height and 40.5% protein. Although it does not have genetic disease
or SCN resistance, it is a hardy line that stands well and yields well. This line is currently
undergoing a seed increase and will be entered into the 2010 State Variety Trials.
MUSTANG is an older variety that has also continued to do well in yield trials. It is a
conventional line with a relative maturity of 4.2. Mustang has white flowers, grey pubescence,
tan pods and buff hila. It averages 43” in height and 39% protein. It is resistant to SCN race 3
and moderately resistant to races 1 and 14. This line is currently undergoing a seed increase and
will be entered into the 2010 State Variety Trials.

MUEXP3901 is high-yielding conventional indeterminate variety with relative maturity 3.9. It is
resistant to SCN race 3 and is tolerant to phytophthora root rot. In several tests, it has been found
to be resistant to sudden death syndrome. It has white flowers, tawny pubescence, tan pod walls
and buff hila. It averages 37” in height and 40% protein. This line has not yet been released but
is entered into the 2009 State Variety Trials.

MUEXP4010 is a conventional line with relative maturity 4.2. It is resistant to race 3 of SCN,
susceptible to SDS and tolerant to phytophthora root rot. It averages 41% protein and 39” in
height. It has white flowers, tawny pubescence and black hila. This line has not yet been released
but is entered into the 2009 State Variety Trials.

 MUEXP1013 is an indeterminate, conventional line with relative maturity of 3.6. The fatty
acids of this line have been modified through non-GMO methods so that the linolenic level is
2.4%. It is highly SDS resistant but not resistant to SCN. It has purple flowers, grey pubescence,
tan pod walls and brown hila. It averages 42” in height and 39% protein. This line is for
producers who have contracts to grow low-linolenic soybeans. Contact MU Soybean Breeding if
you would like more information about this variety. It is not entered in the State Variety Trials.

For any questions about varieties or where to obtain seeds contact:
MU Northern Soybean Breeding or
Missouri Crop Improvement Association
3211 Lemone Industrial Blvd.
Columbia, MO 65201-7600
Phone (573) 449-0586
Fax (573) 874-3193
E-mail: moseed@aol.com
Internet: www.moseed.org
MU EXTENSION SCOUTING MISSOURI FOR SOYBEAN RUST IN 2009
Allen Wrather
Professor

University of Missouri Extension staff will scout select Missouri soybean fields for rust in 2009.
The objective of this project is to detect soybean rust when it first starts to develop in Missouri
soybean fields. Once the disease is detected, an all-out alert will be issued to farmers using radio
and other media. Farmers can then take action to protect their crop against this disease. Contact
Allen Wrather, wratherj@missouri.edu, for more information about this project. Individuals
interested in more information about soybean rust spread in the U. S. can go to www.sbrusa.net.
This web site shows a map of the U. S. indicating areas scouted for rust and areas were rust has
developed.

This University of Missouri Extension project is supported by the soybean farmer checkoff
through the North Central Soybean Research Program. This group and the USDA supported the
rust survey in Missouri from 2005 through 2008, but the USDA has severely reduced their
financial support for this project during 2009. To adjust to this reduced budget, MU Extension
will examine eight sentinel fields in Missouri for rust (four in southeast and four in southwest
Missouri) from mid-August to mid-October rather than survey 20 sentinel fields around Missouri
from mid June to late-October as in 2005 to 2008. Extension staff will survey three additional
sentinel fields in central Missouri if rust develops near Missouri by early September.

Missouri farmers and crop consultants may have soybean leaves examined for rust and other
diseases at the University of Missouri Plant Diagnostic Clinic. Soybean leaves and a moist paper
towel should be sealed in a plastic bag, and these should be sent immediately by express mail to
the clinic along with a completed information form. The information form and more instructions
about collecting and mailing samples to the clinic are posted at
http://soilplantlab.missouri.edu/plant/index.htm. You may also call, 573-882-0623, or email the
clinic, plantclinic@missouri.edu, about this and other services they provide. The clinic can also
provide diagnosis and management information for other soybean problems including diseases,
insects, and weeds. There is a $15 fee for examination of samples submitted to the diagnostic
clinic.
EFFECTS OF BUFFER STRIP INSTALLATION ON RUNOFF,
DISSOLVED ORGANIC MATTER AND SOIL ORGANIC MATTER
Kristen Veum                                                                        Keith Goyne
Graduate Student                                                                Assistant Professor
Peter Motavalli                                                              Ranjith Udawatta
Associate Professor                                                   Research Assistant Professor
                                                                             Harold E. Garrett
                                                                                          Professor
Introduction:
Organic matter plays several important roles in the biogeochemistry of soil and impacts the
sustainability and profitability of agroecosystems (Doran et al., 1994). Retention and
transformation of soil organic matter (SOM) is affected by agronomic and conservation
management practices (Bertol et al., 2007; Christopher et al., 2009) including the installation of
vegetated buffer strips (Liu et al., 2008; Tate et al., 2004). The primary objectives of this study
are to evaluate the effect of grass and agroforestry buffer strips on 1) dissolved organic carbon
(DOC) in runoff and 2) SOM quantity and quality.

Methods and Materials:
The Greenley Memorial Research Center is located in the central claypan region of Missouri,
USA (Figure 1). The study site consists of three watersheds no-till planted to a corn-soybean
rotation. Grass and agroforestry contour buffer strips were installed in 1997 in the west and
center watersheds, respectively. The east watershed serves as a control watershed without buffer
strips. Flumes and autosamplers are located at the outflow of each watershed for collection of
runoff samples. Runoff samples were collected from 1991 (pre-buffer installation in 1997)
through 2006. Soil samples were collected in 2007 from all three watersheds in four landscape
positions. Three subsamples were collected from each management (crop, grass and
agroforestry) and landscape position (summit, shoulder, backslope and toeslope) combination for
a total of 36 sample locations. At each location, soils were sampled at two depths, 0-2 inches and
2-5 inches.
                          West (Grass)   Center (AGF)    East (Control)




                                                                N




Figure 1. Location of the Greenley Memorial Research Center in Missouri, USA and layout of
the study watersheds. Location of flumes and autosamplers (triangles), elevation contour lines
(meters above sea level; black lines), grass waterways and buffer strips (grey lines).


Runoff Study:
Runoff was collected from all three watersheds for a six-year calibration period (1991 – 1997)
and for a nine-year treatment period (1997 – 2006) after the buffer strips were installed. Data
from these two periods were compared using a paired-watershed approach to evaluate the effects
of buffer installation on runoff and DOC loss. The grass buffers significantly reduced runoff by
8.4% (Figure 2a). No significant difference was found in DOC loss for either type of buffer
(grass and agroforestry), indicating that vegetative buffer strips do not contribute to DOC
contamination of surface waters (Figure 2b). These results were published in Agriculture,
Ecosystems and the Environment (Veum et al., 2009).
                 2000                                                                     10
                             West                                                                        West
                 1600        Center                                                       8
                                                                                                         Center
                             West Fit                                                                    West Fit




                                                                      DOC loss (kg ha )
                                                                                                         Center Fit




                                                                      -1
                             Center Fit
Runoff (m ha )
-1




                 1200                                                                     6
3




                 800                                                                      4


                 400                                                                      2

                                                              a                                                                         b
                   0                                                                      0
                        0   400      800    1200       1600   2000                             0     2          4     6        8            10
                                                   3    -1                                                                         -1
                            East (Control) Runoff (m ha )                                          East (Control) DOC loss (kg ha )

                  Figure 2. Paired watershed relationships between control and treated watersheds for (a) runoff
                  and (b) DOC loss for all years.

                  Current and Future Work:
                   Current and future work at the Greenley Memorial Research Center includes investigating the
                  effects of buffer strip installation on SOM and other soil quality indicators. Soil quality
                  indicators will be evaluated for each buffer treatment and a control: grass, agroforestry and row-
                  cropped soil. In addition, four landscape positions will be evaluated by comparing soils from
                  summit, shoulder, backslope and toeslope landscape positions. The soil quality indicators in this
                  study include bulk density, soil organic carbon (SOC), total nitrogen (TN), water-extractable
                  organic carbon (WEOC), particulate organic matter (POM), enzyme activity and aggregate
                  stability (AS). In addition, spectroscopic methods such as Fourier-transform Infrared (FTIR),
                  visible-near infrared (VNIR) and nuclear magnetic resonance (NMR) will be used to compare
                  the chemical structures of SOM under different management practices.

                  Preliminary results indicate significantly lower AS, SOC and TN in the row-cropped soil versus
                  the grass and agroforestry buffers, while no significant differences are observed between the
                  grass and agroforestry buffer systems. We hypothesize that WEOC, POM and enzyme activity
                  will follow the same pattern. Overall, this study has the potential to elucidate changes in both the
                  quantity and quality of SOM as the result of buffer-strip conservation management practices and
                  landscape position.


                  References:
                  Bertol, I., Engel, F. L., Mafra, A. L., Bertol, O. J., and Ritter, S. R. (2007). Phosphorus,
                          potassium and organic carbon concentrations in runoff water and sediments under
                          different soil tillage systems during soybean growth. Soil and Tillage Research 94, 142-
                          150.
                  Christopher, S. F., Lal, R., and Mishra, U. (2009). Regional Study of No-Till Effects on Carbon
                          Sequestration in the Midwestern United States. Soil Sci Soc Am J 73, 207-216.
                  Doran, J. W., Coleman, D. C., Bezdicek, D. F., and Stewart, B. A. (1994). "Defining Soil Quality
                          for a Sustainable Environment. SSSA Spec. Publ. No. 35," Madison, WI.
Liu, X., Zhang, X., and Zhang, M. (2008). Major factors influencing the efficacy of vegetated
        buffers on sediment trapping: a review and analysis. Journal of Environmental Quality
        37, 1667-1674.
Tate, K. W., van Kessel, C., Atwill, E. R., and Dahlgren, R. A. (2004). "Evaluating the
        effectiveness of vegetated buffers to remove nutrients, pathogens, and sediment
        transported in runoff from grazed, irrigated pastures." University of California Water
        Resources Center.
Veum, K. S., Goyne, K. W., Motavalli, P. P., Udawatta, R. P., and Garrett, H. E. (2009). Runoff
        and dissolved organic carbon loss from a paired-watershed study of three adjacent
        agricultural watersheds. Agriculture, Ecosystems, and Environment 130, 115-122.
GREENLEY RESEARCH CENTER PUBLICATIONS

Nelson, K.A., P.P. Motavalli, and R.L. Smoot. 2009. Dried distillers grain as a fertilizer source
for corn. J. Agric. Sci. 1:3-12.

Nelson, KA., S.M. Paniagua, and P.P. Motavalli. 2009. Effect of polymer coated urea,
irrigation, and drainage on nitrogen utilization and yield of corn in a claypan soil. Agron. J.
101:681-687.

Nelson, K.A., and R.L. Smoot. 2009. Twin- and single-row corn production in Northeast
Missouri. Online. Crop Management doi:10.1094/CM-2009-0130-01-RS.

Noellsch, A.J., P.P. Motavalli, K.A. Nelson, and N.R. Kitchen. 2009. Corn nitrogen response
across a claypan landscape using polymer-coated urea and anhydrous ammonia. Agron. J.
101:607-614.

Udawatta, R.P., R.J. Kremer, HE. Garrett, and S.H. Anderson. 2009. Soil enzyme activities and
physical properties in a watershed managed under agroforestry and row-crop systems.
Agriculture, Ecosystems & Environment. 131:98-104.

Bradley, K.W. and L. Sweets. 2008. Influence of glyphosate and fungicide coapplications on
weed control, spray penetration, soybean response, and yield in glyphosate-resistant soybean.
Agron. J.100:1360-1365.

Motavalli, P.P. and K.A. Nelson. 2008. Use of enhanced-efficiency fertilizers for improved
agricultural nutrient management: Introduction to the symposium. Online. Crop Management
doi:10.1094/CM-2008-0730-01-PS.

Nelson, K.A., P.C. Scharf, L.G. Bundy, and P. Tracy. 2008. Agricultural management of
enhanced-efficiency fertilizers in the north-central United States. Online. Crop Management
doi:10.1094/CM-2008-0730-03-RV.

Bradley, K.W., N. H. Monnig, T. R. Legleiter, and J. D. Wait. 2007. Influence of glyphosate
tank-mix combinations and application timings on weed control and yield in glyphosate-resistant
soybean. Online. Crop Management doi:10.1094/CM-2007-0419-01-RS.

Fang, M., P.P. Motavalli, R.J. Kremer, and K.A. Nelson. 2007. Assessing changes in soil
microbial communities and carbon mineralization in Bt and non-Bt corn residue-amended soils.
Applied Soil Ecology 37:150-160.

Nelson, K.A. 2007. Glyphosate application timings in twin- and single-row corn (Zea mays L.)
and soybean (Glycine max L.). Weed Technol. 21:186-190.

Nelson, K.A., and P.P. Motavalli. 2007. Foliar potassium fertilizer sources affect weed control
in soybean with glyphosate. Online. Crop Management doi:10.1094/CM-2007-0724-01-RS.
Nelson, K.A., G.E. Rottinghaus, and T.E. Nelson. 2007. Effect of lactofen application timing on
yield and isoflavone concentration in soybean seed. Agron. J. 99:645-649.

Donald, W.W., and K.A. Nelson. 2006. Practical changes to single-boom sprayers for zone
herbicide application. Weed Technol. 20:502-510.

Nelson, K.A., W.G. Johnson, J.D. Wait, and R.L. Smoot. 2006. Winter annual weed
management in corn (Zea mays) and soybean (Glycine max) and the impact on soybean cyst
nematode (Heterodera glycines) egg population densities. Weed Technol. 20:965-970.

Scursoni, J., F. Forcella, J. Gunsolus, M. Owen, R. Oliver, R. Smeda, and R. Vidrine. 2006.
Weed diversity and soybean yield with glyphosate management along a north-south transect in
the United States. Weed Sci. 54:713-719.

Mungai, N.W., P.P. Motavalli, R.J. Kremer, and K.A. Nelson. 2005. Differences in yields,
residue composition, and N mineralization dynamics of Bt and non-Bt maize. Nutrient Cycling
in Agroecosystems. 73:101-109.

Mungai, N.W., P.P. Motavalli, R.J. Kremer, and K.A. Nelson. 2005. Spatial variation of soil
enzyme activities and microbial functional diversity in temperate alley cropping systems. Biol.
Fertil. Soils. 42:129-136.

Nelson, K.A., P.P. Motavalli, and M. Nathan. 2005. Response of no-till soybean to timing of
pre-plant and foliar potassium applications in a claypan soil. Agron. J. 97:832-838.

Schmidt, A.A., W.G. Johnson, D.A. Mortensen, A.R. Martin, A. Dille, D.E. Peterson, C. Guza,
J.J. Kells, R.D. Lins, C.M. Boerboom, C.L. Sprague, S.Z. Knezevic, F.W. Roeth, C.R. Medlin,
and T.T. Bauman. 2005. Evaluation of corn (Zea mays L.) yield-loss estimations by WeedSoft®
in the north central region. Weed Technol. 19:1056-1064.

Seobi, T., S.H. Anderson, R.P. Udawatta, and C.J. Gantzer. 2005. Influence of grass and
agroforestry buffer strips on soil hydraulic properties for an albaqualf. Soil Sci. Soc. Am. J.
69:893-901.

Udawatta, R.P., P. Nygren, and H.E. Garrett. 2005. Growth of three oak species during
establishment of an agroforesty practice for watershed protection. Can. J. for Res. 35:602-609

Conley, S., D. Bordovsky, C. Rife, and W. Wiebold. 2004. Winter Canola Survival and Yield
Response to Nitrogen and Fall Phosphorus. Crop Management doi:10.1094/CM-2004-0901-01-
RS.

Cordes, J.C., W.G. Johnson, P. Scharf, and R.J. Smeda. 2004. Late-emerging common
waterhemp (Amaranthus rudis) interference in conventional tillage corn. Weed Technol. 18:999-
1005.
Donald, W.W., W.G. Johnson, and K.A. Nelson. 2004. Zone herbicide application controls
annual weeds and reduces residual herbicide use in corn. Weed Sci. 52:821-833.

Donald, W.W., W.G. Johnson, and K.A. Nelson. 2004. In-row and between-row interference by
corn (Zea mays) modifies annual weed control by postemergence residual herbicides. Weed
Technol. 18:497-504.

Li, J., R.J. Smeda, K.A. Nelson, and F.E. Dayan. 2004. Physiological basis for resistance to
diphenyl ether herbicides in common waterhemp (Amaranthus rudis). Weed. Sci. 52:333-338.

Udawatta, R.P., P.P. Motavalli, and H.E. Garrett. 2004 Phosphorus loss and runoff
characteristics in three adjacent agricultural watersheds with claypan soils. J. Environ. Qual.
31:1214-1225.

Dewell, R.A., W.G. Johnson, K.A. Nelson, J. Li, and J.D. Wait. 2003. Weed management in
no-till, double-crop, glyphosate-resistant soybean grown on claypan soils. Plant Management
Network News. Online. Crop Management doi:10.1094/CM-2003-1205-01-RS.

Donald, W.W. and W.G. Johnson. 2003. Interference effects of weed-infested bands in or
between crop rows on field corn (Zea mays) yield. Weed Technol. 17:755-763.

Hellwig, K.B., W.G. Johnson, and R.E. Massey. 2003. Weed management and economic returns
in no-tillage herbicide-resistant corn (Zea Mays). Weed Technol. 17:239-248.

Sellers, B., R. Smeda, and W. Johnson. 2003. Atrazine May Overcome the Time-of-Day Effect
on Liberty Efficacy. Crop Management doi:10.1094/CM-2003-1111-01-RS.

Beyers, J.T., R.J. Smeda, and W.G. Johnson. 2002. Weed management programs in glufosinate-
resistant soybean (Glycine max). Weed Technol. 16:267-273.

Bradley, P.R., W.G. Johnson, S.E. Hart, M.L. Buesinger, and R.E. Massey. 2000. Economics of
weed management in glufosinate-resistant corn (Zea mays L.). Weed Technol. 14:495-501.

Dirks, J.T., W.G. Johnson, R.J. Smeda, W.J. Wiebold, and R.E. Massey. 2000. Reduced rates of
sulfentrazone plus chlorimuron and glyphosate in no-till, marrow-row, glyphosate-resistant
Glycine max. Weed Sci. 48:618-627.

Dirks, J.T., W.G. Johnson, R.J. Smeda, W.J. Wiebold, and R.E. Massey. 2000. Use of preplant
sulfentrazone in no-till, marrow-row, glyphosate-resistant Glycine max. Weed Sci. 48:628-639.

Johnson, W.G., P.R. Bradley, S.E. Hart, M.L. Buesinger, and R.E. Massey. 2000. Efficacy and
economics of weed management in glyphosate-resistant corn (Zea Mays). Weed Technol. 14:57-
65.
GREENELY ENDOWMENT FOR AGRICULTURAL RESEARCH
Harold Beach
Chairman, Greenley Research Center Advisory Board


We hope you have enjoyed the field day and report. We are striving to expand our efforts to
provide applied research to meet agriculture production needs in the region.

The members of the Greenley Research Center Advisory Board would like to invite your support
of a permanently endowed fund that has been established. The Greenley Endowment for
Agricultural Research (GEAR) will provide operational support for the Greenley Research
Center.

The Greenley Center was established when Hortense Greenley donated the 700-acre farm to the
University. The major objective of the center is to evaluate efficient, profitable crop production
in northern Missouri while emphasizing soil conservation, water quality and energy efficiency.
Researchers study the benefits of reduced tillage, alternative cropping practices, the effects of
new technology and products, variety testing, soil fertility and beef cattle backgrounding. Studies
on water quality and the environmental impact of crop production are being implemented

A form for the GEAR fund is located on the next page and additional forms are available from
the advisory board members or the Greenley Center office. This is an excellent opportunity for
you to support Missouri Agriculture by supporting the Greenley Endowment for Agricultural
Research with your tax deductible gift.
  Greenley Endowment for Agricultural Research




                                                    Members of the Greenley Research Center Advisory Board and
                                                 other friends of the Center have established a permanently endowed
                                                 fund at the University of Missouri. This fund will provide opera-
                                                 tional support for the Greenley Research Center, through the College
                                                 of Agriculture,
                                                 Food and Natural
                                                 Resources.
                                                     The Greenley
                                                 Research Center
was established when Hortense Greenley donated the 700-acre
farm to the University of Missouri. It became part of the
University’s comprehensive out-state research program in 1969
and was dedicated on October 6, 1974. The major objective of
the Center is to evaluate efficient, profitable crop production in
northern Missouri while emphasizing soil conservation, water
quality and energy efficiency. Support the Greenley legacy.
Support Missouri agriculture. Support the Greenley Endowment
for Agricultural Research.


   I wish to show my commitment to the Greenley Center with a gift of:
           $100            $500           $1,000          Other ______
   I wish to pledge $ ____________ payable over __________ year(s).

PAYMENT INFORMATION
  My check, payable to U of MO - Greenley Endowment, is enclosed.
  Please charge my credit card.
Card # ____________________________________ Expiration Date ____________________________
Name ____________________________________ Phone ____________________________________
Address _____________________________________________________________________________
Signature ____________________________________________________________________________

If your gift is securities or other property, please call Darcy Wells at 866-400-4483 (toll free) or 573-882-9003.
All gifts to the Greenley Endowment for Agricultural Research are tax-deductible in accordance with state
and federal income tax provisions. Please return this form to: Office of Advancement, College of Agricul-
ture, Food and Natural Resources, 2-4 Agriculture Building, Columbia, MO 65211

				
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