Small Acreage Irrigation Audit - Furrow _Gated Pipe

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					SMALL ACREAGE IRRIGATION AUDIT                         v4.0                              NOTE: For best result test furrows during seco
Gated Pipe and Cement Ditch - 2010

               Table                                                                             Manual
Land           Audit area acres                 15.0       653400 sq-ft

               Crop                  Pasture/Turf                 24 in. root depth     - OR -
               Soil Type               Silt Loam                   2 WHC (in)           - OR -
               Root Zone WHC                    4 in
               PreIrrig Moisture               20 %                               3.2
               MAD                             50 %                                 2   - OR -
               Root Zone MAD                       2 in

Measurement
               System Type            gated pipe                                  1.5
               Input                mag-flow/flume        tube h (in):              4
               Output                   flume

Application
                             400 gpm                   to field
                             350 gpm                   from field
                               24 hrs of set
                                  8 hrs to advance                                               Back off
                               30 in. centers
                       alternate furrow(s) irrigated
                             100 %"subbing" (horizontal wetting)
                              60 furrows irrigated
                             670 ft. Avg furrow length (ft)

Results
                           4.98    gross inches per set
                           2.68    field inches per set                  Normal
                        100.0%     Field Eff                  34.0% DU
                         53.8%     Irrig Eff
               Min IrrigQ                     1.2 field inches per set
               Max IrrigQ                     3.2 field inches per set
               Unused IrrigQ             936,215 gal per irrig
For best result test furrows during second half of set (after water has advanced to tail ditch)



                                                                     Calc unit
             ac               source>> table                             653400.0 sq-ft

             in. root depth   source>> table                                      2.0 ft
             in/ft            source>> table                                      2.0 in/ft


             %                source>> table                                     50.0 %


                                                                                                       Disclaimer: All Results are
                                                                                 400 IN gpm            based on generalized crop
                                                                                 350 OUT gpm           water data sources. Check
                                                                                  50 gpm Discrepancy   equipment regularly!




                          20 % after advance

                         0.5 furrow density




                                                                                                       Contact:
                                          #REF!
                                        GVIC

                                        GVWUA            $0.33
                                        OMID
                                        Redlands
                                        Ute
                                        Well Water
                                        Private Well

                                        Siphon Tube Discharge (gpm)
                                         head in>         2

Disclaimer: All Results are estimates
based on generalized crop, soil, and           0.75      3
water data sources. Check your                    1      5
equipment regularly!                           1.25      7
                                                1.5     11.5
                                                  2      20
                                                2.5      31
                                                  3      45
                                        pipe dia (in)




                                        Root Zone Depths and Management Allow
                                        http://www.usbr.gov/pn/agrimet/irrigation.
                                        The plant root zone determines the soil depth
                                                        Root
                                                        Zone*
                                           Crop          (ft)
                                        Alfalfa           4
          Denis Reich                   Pasture/T         2
          Water Resources Specialist    Small             3
          970-242-8683                  Beans            2.5
          970-201-8467                  Corn              3
          Denis.Reich@Colostate.edu     Orchard           6
                                        Grapes            3




                                        *Root zones can be limited by shallow soils, c

                                        Soil Water Storage Capacities

                                        The texture of soil to be irrigated is very impo
       Soil
 General  Texture
         Coarse
Light,   Fine Sand
Sandy    Sandy
         Fine
Medium, S-C Loam
Loam     Loam
         Silt Loam
Heavy,   Clay Loam
Clay     Clays;

*Values are for deep, uniform soil profiles. Layerin
                          man/auto?                 Qunits?                  system?                    furrows
                          manual                    gpm                      gated pipe                 flume
                          table                     cfs                      cement ditch               none

                          RD                        mag-flow/flume           every                  1
                          None                      gates/tubes              alternate              2

                                     0


be Discharge (gpm)                  7.5                                                  5
                   4            6           8           10           12


                  5            6           7            8           8.5                  2
                 7.5           9           11           12           13                  3
                  10           13          16           18           20                  4
                  16           20         22.5          25          27.5                 5
                 28.5         24.5         40          44.5         48.5                 6
                  44           53          61           68           73                  7
                  62           76          88           99          107                  8




 Depths and Management Allowable Depletion for Selected Crops
w.usbr.gov/pn/agrimet/irrigation.html#Root
oot zone determines the soil depth from which the crop can draw moisture. This table shows the root zones that mature crops depend on for
               Time to
               Reach       Allowable hay crop? yes
               Mature      Depletion
                  0            55
                  0            50
               heading         55
               50 days         40
               10 days         50
                  0            50    * Orchard listed as "50-65" MAD
                  0            65




s can be limited by shallow soils, compaction layers and dry soil.

 Storage Capacities

e of soil to be irrigated is very important in determining when and how much to irrigate. This table lists the abilities of different soil types to sto
              Available
               Moisture
               per foot
              0.7 inches
                      0.9
                      1.2
                      1.5
                      1.7
                      1.8
                        2
                      2.2
                      2.4

for deep, uniform soil profiles. Layering or changes in soil texture within the profile may increase or decrease effective available water.
 s that mature crops depend on for 90% of their water needs, and the percent of total available moisture that crops can withdraw without suffe




abilities of different soil types to store and make water available to plants.
e available water.
at crops can withdraw without suffering stress or yield loss. This percent is also referred to as "Management Allowed Depletion", or MAD.
nt Allowed Depletion", or MAD.
          Top Measure? bucket
             1. Raw Furrow Flows (gpm)                          3. Subset (low quart of surviving values)
             Top-Flume    Top      Bottom     perc                 Top      Bottom
          1      1.0      10.0      8.0       2.0          1
          2      2.0       8.6      7.5       1.1          2
          3      3.0       7.5      6.5       1.0          3
          4      4.0       5.5      5.0       0.5          4       5.5        5.0
          5      5.0       7.5      6.0       1.5          5                  6.0
          6      6.0       5.0      4.0       1.0          6       5.0        4.0
          7      7.0       6.7      5.5       1.2          7       6.7        5.5
          8      8.0       8.1      7.2       0.9          8
          9      9.0       7.1      6.0       1.1          9                  6.0
         10     10.0       6.8      7.1       0.3         10
         11     11.0       9.1      7.6       1.5         11
         12     12.0       7.3      8.3       1.0         12
         13                7.1      8.2       1.1         13
         14                7.3      6.2       1.1         14
         15                                               15
         16                                               16
         17                                               17
         18                                               18
         19                                               19
         20                                               20
        AVG     6.50      7.40     6.65       1.08
                                                       Addits
Low BotQuart    2.89      6.10     5.37       0.66          a      6.75
Upp BotQuart    4.70      6.75     6.01       0.87          b
Upp TopQuart    10.11     8.71     7.93       1.50          c
       Count      12       14       14         14           d
      TOTAL      78.0    103.6     93.1       15.2          e
       Loss%             78.6%     64.3%     85.7%      AVG        5.97       5.30
   Discarded               11        9         12        DU       80.6%      79.7%

     Median             7.317073    6.8     1.064286
   CountMed                 2        0          0
       addits               1        0          0

                                               214.5
           Top           Bottom        ET=perc
             #REF!         #REF!         #REF!
             #REF!         #REF!         #REF!
       1     #REF!         #REF!         #REF!
       2     #REF!         #REF!         #REF!
       3     #REF!         #REF!         #REF!
       4     #REF!         #REF!         #REF!
       5     #REF!         #REF!         #REF!
       6     #REF!         #REF!         #REF!
       7     #REF!         #REF!         #REF!
       8     #REF!         #REF!         #REF!
       9             0             0             0
      10
AVG            100%          100%          100%
low quart of surviving values)
              perc




              0.5




              0.3




                                 DU type:   Normal
                                     DU:    33.97%




              0.37
             34.0%
bucket
flumes
     1. Gated Pipe Bucket Test (secs)           Bucket Vol:
      sec to fill unit/min   gpm        gpm                   5 gal
 1      30        2.00      10.00       10.00   conversion1           1
 2      35        1.71       8.57        8.57   conversion2           1
 3      40        1.50       7.50        7.50
 4      55        1.09       5.45        5.45
 5      40        1.50       7.50       7.50
 6      60        1.00       5.00       5.00
 7      45        1.33       6.67       6.67
 8      37        1.62       8.11       8.11
 9      42        1.43       7.14       7.14
10      44        1.36       6.82       6.82
11      33        1.82       9.09       9.09
12      41        1.46       7.32       7.32
13      42        1.43       7.14       7.14
14      41        1.46       7.32       7.32
15
16
17
18
19
20
oz
gal
L

oz
      128
        1
gal       L
      1        60
      1   15.85205
Soils     http://websoilsurvey.nrcs.usda.gov/app/HomePage.htm                 Definition
          Soil Type                            Silt Loam                      IR = Infiltration Rate or velocity at which water percolates into the
                                                                              is in good condition or has good soil health, it has stable structure
        2 Slope                                     0-4%
                                                                              pores to the surface. This allows water from rainfall or irrigation to
          Standard IR                                  0.5 in/hr       0.45   Soil can be a excellent temporary storage medium for water, depe
                                                                       0.55   and condition of the soil. Proper management of the soil can help
                                                                              and capture as much water as allowed by a specific soil type.
          Best Avg furrow perc                        65 gph
          Irrigated Area                           15.00 ac
          Best estimated IR (perc)                  0.01 in/hr


Field     Crop                                      grass                     A hardpan layer is a layer of impermeable bedrock or clay that pre
          Depth of hardpan?                            >4 ft                  percolating deeper. A hardpan layer can limit the rooting depth of
                                                                              as alfalfa. It also limits the water storage capacity of soils and can
          Optimal mature root depth                      2 ft                 groundwater flows into neighboring fields.


          Field grade                      reasonably level                   Field topography, furrow pattern, and furrow maintenance are the
                                                                              factors that influence irrigation uniformity and efficiency the most.
          Furrows marked per pass?                      4                     (consistent grade) with a consistent furrow pattern that is remarke
          Last time furrows marked?             this year                     best "canvas" for an irrigator to "paint" on.




Water     Furrow DU                                34.0%                      DU = Distribution Uniformity and is a measure of how consistent ir
                                                                              the irrigation zone. The amount of water absorbed per furrow is the
          Set time                                    24                      DU in this calculation. DU can be measured many ways with furro
          Time to advance?                              8                     should be a guide only. Typically below 50% is seen as problemat
                                                                              and above 60% is good.
          Reduce flows post-advance?                   no          1
          Separate Irrig for wheel rows?               no          1


Eff seas Irrigation frequency?                >bi weekly                      Even with optimum field conditions, astute irrigation scheudling is
                                                                              maximizing returns on your investment. Scheduling should be bas
          Season Length?                            232       days            moisture the root zone soil can hold and how rapidly it is being dep
          Number of irrigations                      11       /seas           consumption, evaporation and percolation. Monitoring soil moistur
                                                                              maximizing water use by the crop - known as EvapoTranspiration
          Approx Water Applied                    55.02       in.             Consumptive UIse (CU) - and optimizing yield. Crop water use info
          Healthy ET                              27.45       in.             online at www.coagmet.com (daily) and from the Colorado Irriga
          Seasonal Efficiency                    49.89%                 0.9   (seasonal averages). Furrow irrigation typically has a seasonal eff
                                                                                                    www.coagmet.com
                                                                              less than 50% of water applied is used by the crop. A seasonal eff
                                                                        1.1   25% is considered poor.
          Evidence of crop stress?                     no
                                                                Analysis and Recommendations
 ity at which water percolates into the soil. When the soil     Sub-optimum infiltration: means there is a risk that the majority of water is running off
ood soil health, it has stable structure and continuous         the field and minimal water is contributing to crop growth. Symptoms of sub-optimal
ows water from rainfall or irrigation to enter unimpeded.       infiltration are ponding and localized flooding problems, mosquito outbreaks, soil
orary storage medium for water, depending on the type           erosion, fertilizer loss, and reduced yields. Recomendations: 1. reduce compaction by
 per management of the soil can help maximize infiltration      following the same wheel ruts; 2. maintain plant matter or use cover crops; 3. add
as allowed by a specific soil type.                             organic matter which can be done by reducing tillage operations (which also reduces
                                                                trips accross the field). Important: clay soils will crack as they dry. When water
                                                                contacts with a cracked clay soil infiltation will be rapid, decreasing as the soil swells.
                                                                The IR number calculated here does not account for this phenomenon.




 impermeable bedrock or clay that prevents irrigation           No Hardpan or deep hardpan layer: the available root zone is sufficient to support
an layer can limit the rooting depth of certain crops such      your planted crop.
ater storage capacity of soils and can influence
 boring fields.

 ern, and furrow maintenance are the three physical             Even grade field: is a good foundation for effective irrigation. It's important that this is
on uniformity and efficiency the most. A level field            matched with a consistent, well marked furrow pattern.
nsistent furrow pattern that is remarked every year is the
 to "paint" on.                                                 Well designed and maintained furrows: compliments an evenly graded field as the
                                                                basis for maximizing the returns on your irrigation management.



 and is a measure of how consistent irrigation is across        Poor DU (<50%) could be a result of too much flow. Recommendation: try cutting
 unt of water absorbed per furrow is the metric used for        back water after advancing.
  n be measured many ways with furrow systems so
 cally below 50% is seen as problematic, 50-60% is fair,
                                                                Additional DU recommendations: explore irrigating wheel rows with a separate regime
                                                                to non-wheel rows.




 ditions, astute irrigation scheudling is paramount to          Seasonal Irrigation Efficiency is good. Continue to monitor soil moisture and local ET
 nvestment. Scheduling should be based on what                  values to enhance your irrigation management.
 an hold and how rapidly it is being depleted by crop
nd percolation. Monitoring soil moisture is key to
  crop - known as EvapoTranspiration (ET) or
 d optimizing yield. Crop water use information is available
m (daily) and from the Colorado Irrigation Guide, 1988
  irrigation typically has a seasonal efficiency of <50%; i.e
 ed is used by the crop. A seasonal efficiency of less than
               Soil Texture, Type

               Coarse Sand
               Fine Sand
               Sandy Loam
               Fine Sandy Loam
               S-C Loam
               Loam
               Silt Loam
               Clay Loam
               Clays; Peats/Mucks
               ref: USDA




               CIG Fruita
Pasture/Turf   grass
Alfalfa        alfalfa
Corn           corn (grain)
               corn (silage)
Small Grains   winter grain
               spring grain
Beans          dry beans
Orchard        orchard (cover)
               orchard (no cover)
               vegetables
Grapes         Grapes
IR Infil rate (in/hr)                1 none      laser levelled             3 <weekly       3.5
0-4%         5-8%                    2         1 reasonably level           4 weekly          7
       1.25            1             3       1.5 somehwat uneven            5 1-2 weekly   10.5
       0.94         0.75             4         2 uneven IR                  6 biweekly      14
       0.75          0.6             5       2.5 highly vairable slope      7 >bi weekly    21
       0.63          0.5             6         3                            8
       0.32         0.26             7       3.5                     variable
       0.54         0.43             8         4
        0.5          0.4             9 >4                    this year
       0.25          0.2           10 .                      last year
       0.13          0.1           11                        before last year
                                   12
                                   13                        yes              grain
                                   14                        no               silage
                                   15
                                   16                                         winter
                                   17                                         spring
                                   18
                                                                              cover
Days          Weeks        Precip Eff CU         Irrig                        no cover
       232         33.1          3.99      31.44       27.45
       217         31.0          3.98      36.22       32.24
       158         22.6          2.87      25.12       22.25           Corn? grain
       133         19.0          2.42      22.67       20.25
       112         16.0          2.56      18.95       16.39 Small Grains? winter
       122         17.4          1.84      19.61       17.77
       107         15.3          2.07      19.93       17.86
       192         27.4          3.62         35       31.38        Orchard? cover
       172         24.6          3.01      25.71        22.7
       139         19.9          2.13      18.06       15.93
       153         21.9            2.8        10         7.2
Soils   Sub-optimum infiltration: means there is a risk that the majority of water is running off the field and minimal water
        Optimum or above optimum infiltration: soils are well maintained. Check measurements for above optimum flows

Field   Shallow hardpan layer: the available root zone is less than the planted crop needs for healthy growth. Recommen
        No Hardpan or deep hardpan layer: the available root zone is sufficient to support your planted crop.

        Uneven fields: with uneven fields consistently successful irrigation requires a large labor input. Recommendations
        Even grade field: is a good foundation for effective irrigation. It's important that this is matched with a consistent,
        Poor furrow pattern / maintenance: limits irrigation uniformity. Recommendations: 1. even numbered furrow pat
        Well designed and maintained furrows: compliments an evenly graded field as the basis for maximizing the return

        Poor DU (<50%) could be a result of trying to irrigate too many furrows. Recommendation: try sharing water with
        Poor DU (<50%) could be a result of too much flow. Recommendation: try cutting back water after advancing.
        Poor DU (<50%) could be a result of irrigating wheel and non-wheel rows the same. Recommendation: Irrigate sep
        Poor DU (<50%). It is unclear why DU is low. Consult with auditor.
        DU Okay (>50%) - to improve DU, pay attention to advance time, flows after advance and furrow types.

        Seasonal Irrigation Efficiency is sub-optimum. More than 75% of the water applied to the field is not being absorb
        Seasonal Irrigation Efficiency could be improved. More than 65% of the water applied to the field is not being abs
        Seasonal Irrigation Efficiency is good. Continue to monitor soil moisture and local ET values to enhance your irriga
        Irrigation water applied is not even matching crop demand!
        Crop is also showing signs of stress           which might be due to lack of or surplus water to the crop, or salinit
                                                       which are probably due to over-irrigation which can lead to drownin
        Recommendation: Efficiency is function of many variables. Discuss irrigation scheduling and set programming with


        Evidence of crop stress?            explore cutting back on irrigation flows before/after water advances - one or bo
                                            explore irrigating wheel rows with a separate regime to non-wheel rows
ing off the field and minimal water is contributing to crop growth. Symptoms of sub-optimal infiltration are ponding and localized flooding prob
rements for above optimum flows and be careful that deep percolation and/or groundwater flows are not interferring with neighboring ir

ds for healthy growth. Recommendations: 1. plant a hardy shallow rooting crop like grass hay; 2 minimize trash removal to build organic m
 rt your planted crop.

ge labor input. Recommendations: contact NRCS for help levelling your field.
 this is matched with a consistent, well marked furrow pattern.
ons: 1. even numbered furrow pattern; 2. remark annually
he basis for maximizing the returns on your irrigation management.

mendation: try sharing water with neighbors or irrigating less rows.
ng back water after advancing.
me. Recommendation: Irrigate separately with different flows.

vance and furrow types.

ed to the field is not being absorbed by the crop.
pplied to the field is not being absorbed by the crop.
al ET values to enhance your irrigation management.

urplus water to the crop, or salinity issues
rigation which can lead to drowning the crop.
eduling and set programming with auditor.


e/after water advances - one or both may be too high.
 regime to non-wheel rows
ponding and localized flooding problems, mosquito outbreaks, soil erosion, fertilizer loss, and reduced yields. Recomendations: 1. reduce com
ot interferring with neighboring irrigation water management or river basin salinity problems.

e trash removal to build organic matter; 3 avoid deep rooting crops like alfalfa.
ds. Recomendations: 1. reduce compaction by following the same wheel ruts; 2. maintain plant matter or use cover crops; 3. add organic ma
se cover crops; 3. add organic matter which can be done by reducing tillage operations (which also reduces trips accross the field). Importa
es trips accross the field). Important: clay soils will crack as they dry. When water contacts with a cracked clay soil infiltation will be rapid, de
clay soil infiltation will be rapid, decreasing as the soil swells. The IR number calculated here does not account for this phenomenon.
count for this phenomenon.
SMALL ACREAGE AUDIT REPORT - FURROW
             RESULTS                              ANALYSIS
General           Date:     11/22/2011            General Comments
               Location:
                Auditor:


Field              Acres:     15.00               Specific Comments
               Soil Type:  Silt Loam              No Hardpan or deep hardpan layer: the available root zone is sufficient to support yo
                  Soil IR:     0.01    in/hr
                    Crop: Pasture/Turf


Audit            System     gated pipe            Even grade field: is a good foundation for effective irrigation. It's important that this
                    DU:       34.0%               consistent, well marked furrow pattern.
                Snap Eff:    100.0%               Well designed and maintained furrows: compliments an evenly graded field as the ba
                Seas Eff:     49.9%               the returns on your irrigation management.
                                                  Poor DU (<50%) could be a result of too much flow. Recommendation: try cutting b
                                                  advancing.
Irrigation    Set applic:      4.98      inches   Seasonal Irrigation Efficiency is good. Continue to monitor soil moisture and local E
              Set length        24       hours    your irrigation management.
                 Set CU:       2.68      inches
             Un-needed:      936,215     gal



                                                  CSU Extension Water Resources: Western Region: 970-242-8683.




                                                  Colorado State University, U.S. Department of Agriculture and Colorado counties cooperatin
                                                  Extension programs are available to all without discrimination.
t zone is sufficient to support your planted crop.




igation. It's important that this is matched with a

an evenly graded field as the basis for maximizing

Recommendation: try cutting back water after

onitor soil moisture and local ET values to enhance




gion: 970-242-8683.




 and Colorado counties cooperating.
  43560    sq-ft per acre
    7.48   gal per cu-ft
325851.4   gal per ac-ft
   448.8   gpm per cfs
27154.28   gal per ac-in

				
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