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Field Day Report 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: firstname.lastname@example.org. 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: email@example.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, firstname.lastname@example.org, 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, email@example.com, 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
"Greenley Memorial Research Center"