irrigation management practices

IrrigationManagement Practices

Lyndon KelleyMSU Extension / Purdue University Irrigation Management Agent

WWW.msue.msu.edu - find St. Joseph Co. - then hit the Irrigation button

Thanks to Dr. Ted Loudon - MSU Ag Engineering Dr. Ron Goldy - MSU Extension

Dr. Jeff Andreasen – MSU Geography Dr. Steve Miller - MSU Ag Engineering

http://www.msue.msu.edu/

Tools for Irrigation Stewardship

1. Irrigation System Uniformity

2. Preventing Irrigation Runoff (comparing irrigation application rate to soil infiltration rate)

3. Irrigation Scheduling

4. Backflow protection

5. Avoiding water use conflicts

6. Record keeping

Irrigation power cost vary on: - power source - power cost - system pressure

Average fuel cost for pumping NE. USA: 2006 Cost per acre inch of irrigation waterEnergy source

PressureElectric Diesel / propane

Low <35 psi $1.76 $2.56 / 2.30Med. 35 to 95 psi $2.48 $3.76 / 3.27High >100psi $ 3.56 $ 4.87 / 3.90

Day to Day

Power Operation

Costs

Table 2. Comparative Costs of Various

Energy Sources to Obtain Equal Work Output per Dollar

SpentSource: AE-111 Comparable

Costs of Various Energy Sources for Irrigation

Pumping

Gasoline ($/gallon) Diesel ($/gallon) Propane ($/gallon) Electricity (kw-hr)

.90 1.18 .71 9.4

1.00 1.31 .79 10.4

1.10 1.44 .87 11.4

1.20 1.57 .95 12.5

1.30 1.70 1.03 13.5

1.40 1.83 1.11 14.6

1.50 1.97 1.19 15.6

1.60 2.10 1.26 16.7

1.70 2.23 1.34 17.7

1.80 2.36 1.42 18.7

1.90 2.49 1.50 19.8

2.00 2.62 1.58 20.8

2.10 2.75 1.66 21.8

2.20 2.88 1.74 22.8

2.30 3.01 1.82 23.9

2.40 3.14 1.90 25.0

2.50 3.27 1.98 26.0

2.60 3.40 2.06 27.0

2.70 3.53 2.13 28.1

2.80 3.67 2.22 29.2

2.90 3.80 2.29 30.1

3.00 3.93 2.37 31.2

Scientific Investigations Report 2005–5284U.S. Department of the InteriorU.S. Geological Survey

Estimated rainfall recharge

0

1

2

3

4

5

6

7

Jan Feb Mar Apr May June July Aug Sept Oct Nov Dec

Inch

es o

f Wat

er

Corn Water UseNormal Rainfall

Crop need15.6” total

Normal rainfall34.6

Needed Irrigation5.5”

0

10000

20000

30000

40000

50000

60000

70000

80000

90000

100000

1969 1974 1978 1982 1987 1992 19970

10

20

30

40

50

60

70

St. Joseph Co.Kalamazoo CoSturgis wellSchoolcraft well

Thirty years of Increasing Irrigation have not Impacted Municipal Water Well Depths

Have you seen yield map patterns that match the irrigation system

configuration?

• Irrigator trainings (Extension, SCD, NRCS )• Private consultants• SCD

Irrigation System Uniformity -Options

Irrigation System Uniformity

An 1” application should be 1” everywhere in the irrigated field

•10% or less deviation from the average is ideal.•Over applied area will likely be over applied each application•Under applied areas will likely be under applied each application

A 30% deviation on a field in an 8” irrigation application year will have areas receiving as little as 5.6” and as great as 10.4”

Repair all visible system leaks and problems first.

Evaluating Irrigation System Uniformity

Standards and Methods for Evaluation of Irrigation System Uniformity

• Two commonly accepted standards or methods are available as guidelines for performing evaluations of Irrigation System Uniformity.

• ASAE Standards (436.1) — Available at: http://www.kbs.msu.edu/mgsp/resources.htm

• NRCS Handbook — Available at your local Natural Resource Conservation Service office or http://www.wcc.nrcs.usda.gov/nrcsirrig/irrig-handbooks-part652-chapter15.html

http://www.kbs.msu.edu/mgsp/resources.htm


Basic system evaluation

Collect enough uniform container to to place every 10 feet the length of the system or across the application pattern.

Spread the container every ten feet from the center point to the outside edge of the application area.

Run the machine at standard setting over the container.

Measure and record the water volume caught by each container

Note sample point varying greater than 50% of the average.

Evaluating Irrigation Uniformity Catch can

stands

A simple , inexpensive catch can stand can be built using:1. 32 oz. Deposable soda cup (Taco Bell cup)2. 3” plastic drain pipe cut to 5” in length3. 2”x3” stud cut to length to wedge into plastic drain pipe 4. Drill hole 1.5” into cut 2”x3” stud chucks, drill hole should

snuggly fit electric fence post 5. Steel ( step in ) electric fence post

Electric fence post and cups can be stored and transported in separate stacks. The 2”x3” stud chucks wedge into the base of the cut plastic drain pipe sections and make the transition between the cup and post. Screw maybe pace through the side of the plastic drain pipe into the 2”x3” stud chucks.

Total cost per unit is less than a dollar and require only a saw, drill and screw driver. It will allow data collection

Evaluating Irrigation System Uniformity

Pivot Extensions (cornering arm or Z-arm)• Some center pivot irrigation systems are designed to

expand the wetted area to allow coverage of corner or odd-shaped fields, often referred to as cornering arms or Z-arm. These systems require two separate evaluations if the extension accounts for 30 percent or more of the irrigated portion of the field. One evaluation will evaluate the system while extended, and a second when the arm is not deployed.

Overview of Evaluation of Irrigation System Uniformity Guidelines (center pivot)

1. Have the producer walk the system length and note any application problems while the system is applying water. All known application problems need to be corrected before doing an evaluation of Irrigation System Uniformity.

2. Have the producer start the system and establish a setting for his normal application (avoid weather extremes).

3. Run the system for 10 minutes or more without changes to water supply system.1. Place catch cans in a line from the center pivot point past the outer edge of the wetted

area. 2. Catch cans should be placed to form a straight line from the pivot point to a point on the

outer edge of the wetted area.3. Space catch cans 20 feet apart for system overhead impact sprinklers, and 10 feet apart

for all other center pivot application systems. 4. Place catch cans with opening at a height above the crop, or in a field opening width four

times greater than the height difference between the crop and catch can opening.5. A drop of mineral oil may be added to each catch can to minimize evaporation if a

reading cannot be taken immediately and conditions favoring evaporation are prevalent.6. If the catch can placement falls into the wheel tracks, it may be moved one to two feet to

avoid damage. 4. Record the number of catch cans placed, the producer’s intended application,

catch can opening diameter and other pertinent information. A sample record sheet to use for data collection follows.

5. Record volume collected from each catch can (ml.).6. Record the locations of pivot wheel lanes

Evaluation of DataCleaning the Data1. Catch can data from the first 10 percent of the system length closest to the

center pivot point should be ignored. The “average catch can (ml)” data replaces the first catch can data points. The actual “distance from center point” is entered for the first data point (remaining after deletion of other points closer to the center pivot point). Coverage near the center point of the system represents such a small amount of the total system coverage deviation from the average, that it yields little effect on the machine’s overall uniformity.

2. Catch can data from the outer edge of the wetted area is deleted from the data set when the volume is less than 70 percent of the average. Removing the data that tails off at the outer edge of the system designates the effective irrigated area, and avoids dilution of the data points representing the actual targeted irrigated area.

3. Up to three percent of the data points should be removed if it is an extreme deviation from the average. This is done after the outer edge data has been removed to define the effective irrigated area and up to 20 percent of the inner area data has been removed. A few catch cans could collect extreme data that is not representative of the system area, like water running from a trust rod or brace rod directly to the cup.

System Uniformity Coefficient

1. System Uniformity Coefficient is a numeric judgment of the overall performance of an irrigation system’s ability to evenly apply water to the field.

2. A System Uniformity Coefficient of 85 percent or greater, is considered not to need major adjustments to the sprinkler package, although individual sections of the irrigator may benefit from corrections (green or black in the spreadsheet).

3. System Uniformity Coefficient of 80 to 85 percent may need further analysis of the sprinkler package, and individual sections of the irrigator would benefit from corrections (yellow in the spreadsheet).

4. System Uniformity Coefficient of less than 80 percent requires an adjustment to the sprinkler package design and correction of individual sections of the sprinkler package (red in the spreadsheet).

2640’

Field #9

Field #9

Creating a Take-home Message for the ProducerThe System Uniformity Coefficient provides the producer with a

report of the overall performance of the system. Almost all systems will benefit from some corrections.

Correction of areas of the system with greater than 20 percent deviation from average (red in the spreadsheet) will improve performance.

Entering a second data set, replacing the red (high deviation) data with the “average catch can (ml)” data, will create a before/after scenario that will identify the benefits of repairs or corrections to the system.

Graph of performance The Excel spreadsheet can produce a line graph of systems

uniformity. The data will not be weighted for coverage area represented by each cup.

Entering pivot wheel tracks into the graph using Microsoft standard AutoShape will make the graph more usable to irrigators.

Catch Can Volume (ml)

0

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180

0 200 400 600 800 1000 1200 1400 1600Distance from Pivot (ft)

Can

Volu

me

(ml)


Tower 1

Tower 3

Tower 5

Tower 7 Tower

8

Sprinkler overlap with end gun

http://web1.msue.msu.edu/stjoseph/anr/anr.htm


•Most system are designed to have 90% or better uniformity

•Changes in volume and pressure from design parameters will cause reduction in uniformity

•Some sprinklers can perform well over a large change in pressure over others

•Multiple overlaps tends to reduce potential problems

Greatest improvement needed• End gun stop adjustment

• Water supply over or under design

• End gun orifice, too little or too much

• Wrong sprinkler or tip

• Leaks, plugs and no turn sprinklers

Water supply over or under designsupply over design yield tail up, supply under design yield tail down

Example of Water supply under volume for sprinkler design


Tower 1 Tower 2 Tower 3


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0 100 200 300 400 500 600 700Distance from Pivot (ft)

Can

Volu

me

(ml)

Catch CanVolume (ml)

Poly. (CatchCan Volume(ml))

tower 3tower 1 tower 2

tower 4


0

50

100

150

200

250


Can

Volu

me

(ml)

Catch CanVolume (ml)

Poly. (CatchCan Volume(ml))

tower 5tower 1 tower 3 tower 7

165’

825’

1320’1155’

8 acres6 acres330’

495’

660’

990’

2 acres

18 acres31 acres

49 acres

71 acres

96 acres126acres

10 acres

13 acres

18 acres

22 acres

25 acres

30 acres

Total Acres

Feet from center

4145’3109’

2072’

5181’6217’

7253’8290’

circumference

Over and under

application issue affect the majority

of the application

area

Most system apply within 85% of the expected application

Application is 4 %

under expectation

Measure flow at desired pressure prior to ordering sprinkler package

Poor performance:

Ask dealer to measure flow at peak water use season and compare to design parameters.

Preventing Irrigation Runoff (comparing irrigation application rate to soil

infiltration rate)


infiltration rate)

Sprinkler package or nozzle selection along with pressure dictates water application rate .

Factors that increase runoff :•Small Wetted area or throw of sprinkler•Low Pressure •Larger applications volumes•Soil compaction•Heavy soils•Slope•Row hilling

Instructions for completing the Evaluating Potential Irrigation Runoff form :

1. Identify the areas of the irrigated field that has the lowest

infiltration rates. (heavy soils, slopes, surface compaction).

2. Select a transit line in the wetted area just behind the machine that covers the identified lowest infiltration rates of the field identified above.

Instructions for completing the Evaluating Potential Irrigation Runoff form – continued

3. Pace or measure 50 feet between observations starting at

the pivot point and progressing to the furthest reaches of the machine.

4. Record observations for each location; look at several (4-5 areas) representing the row contour and differences in row traffic of the location. Record any specific concerns that may affect the application (drips or leaks) or affect the soils ability to take in water (compaction, row contours)

Key for Observation column A- no observed puddling, ponding or sheen between rows B- puddling, ponding or sheen between rows identified, but no observed runoff or flow of water C-observed runoff or flow of water

Calculating Instantaneous Application Rate

• Flag the leading edge of the wetted area just inside of the last tower of the pivot.

• Running the pivot at common speed with a measured and known application rate.

• Using a stop watch measure the time elapsed from the first drops hitting the flag till the last.

• Divide the measured and known application rate for the spot by the time elapsed.

• Convert to Minute to provide 1 inch application.

Instantaneous Application Rate

1.Time it from first drop of irrigation to last 2.Divide by know application rate3.Convert to minute to provide 1” of irrigation

Instantaneous Application Rate

John applied .75 inches in 21 minute

.75 inches = 1.00 inches 21 min. ? = 28

min./inch

The Goal

• Apply a consistent uniform amount of water over the whole field.

• Apply water at a rate (volume/time ) that can infiltrate into soil avoiding runoff.

• Avoid water loss to air or off target.

The larger the wetted area the slower the rate of application.Average 1’ rainfall comes over 4 hours.

An 1’ rainfall over an hour is considered a “Toad strangler”

Sprinkler packages are commonly available with instantaneous application rates from 1” per 12 minutes to 1” per 80 minutes

Height


infiltration rate)

Management factors that increase runoff:•Larger applications volumes•Soil compaction•Heavy soils•Slope•Row hilling


Sprinkler package or nozzle selection along with pressure dictates water application rate .

Factors that increase runoff:•Small wetted area or throw of sprinkler•Low Pressure

Instantaneous application

rate

165’

825’

1320’1155’


495’

660’

990’

2 acres

18 acres31 acres

49 acres

71 acres

96 acres126acres

10 acres

13 acres

18 acres

22 acres

25 acres

30 acres

Total Acres

Feet from center

4145’3109’

2072’

5181’6217’

7253’8290’

circumference

3 days / circle @ 1”3 days = 4320 min.

8290’ / 4320 min.= = 1.92’/minute

20’ ft. wetted area== 1” / 10.4 Minutes

40’ ft. wetted area== 1” / 20.8 Minutes

Irrigation Scheduling Checkbook Method

Think of your soil as a bank

Intake rate:Water applied faster than the soil intake rate is lost.

Deletion:Plants can pull out only 30 - 60% of the water

Water holding capacity:The soil (bank) can hold only a given volume of water before it allow it to pass lower down.

Rooting depth:The plant can only get water to the depth of it’s roots.

Soil type :Heavier soil can hold more water / foot of depth than light soils

Water lost from the bottom of the profile can wash out (leach) water soluble nutrients and pesticides.

Soil Name

DepthInches

Available water holding capacity

Average Available water holding capacity

Ave. Available water holding capacity ( 24 in.)


Oshtemo 0 - 1414 – 3535 - 60

0.10 – 0.150.12 – 0.190.06 – 0.10

0.1250.1550.08

14” x 0.125=1.7510” x 0.155=1.55----------------------- = 3.3

14” x 0.125= 1.7521” x 0.155= 3.26 1” x 0.08 = 0.08----------------------- = 5.09

Spinks 0 – 1010 – 2626 - 60

0.08 – 0.100.08 – 0.100.04 – 0.08

0.090.090.06

10” x 0.09= 0.914” x 0.09= 1.26----------------------- = 2.16

10” x 0.09= 0.916” x 0.09= 1.26 8” x 0.06= 0.48----------------------- = 2.64

Calculating Water Holding Capacity

Soil Name

DepthInches

Available water holding capacity

Average Available water holding capacity



Bronson 0 - 1011 – 2627 – 3435 - 60

0.13 – 0.150.12 – 0.180.06 – 0.080.02 – 0.04

0.140.150.070.03

10” x 0.14=1.414” x 0.15=2.7----------------------- = 4.1

10” x 0.14=1.416” x 0.15= 3.26 8” x 0.07 = 0.562” x 0.03 = 0.06----------------------- = 5.28

Spinks 0 – 1010 – 2626 - 60

0.08 – 0.100.08 – 0.100.04 – 0.08

0.090.090.06

10” x 0.09= 0.914” x 0.09= 1.26----------------------- = 2.16

10” x 0.09= 0.916” x 0.09= 1.26 8” x 0.06= 0.48----------------------- = 2.64

Calculating Water Holding Capacity

Available Water Holding Capacity

Soil Type/ depth

Bronson Capac Oshtemo Spinks

0”to 6”0”to 6”

.84” .84”

1.2”1.2”

.75”

.75”.54”.54”

6”to 12”0”to 12”

.86”1.70”

1.2”2.4”

.75”1.50”

.54”1.08”

12’ to 18”0”to 18”

.90”2.60”

.99”3.39”

.87”2.37”

.54”1.62”

18’ to 24”0” to 24”

.90”3.50”

.99”4.38”

.93”3.30”

.54”2.16”

24’ to 30”0” to 30”

.58”4.80”

.99”5.37”

.93”4.23”

.42”2.58”

30” to 36” 0”to 36”

.34”5.14”

.93”6.30”

.86”5.06”

.36”2.94”

Rain Gauges

• Basic unit – 2 inch opening

• Cost less than $10• One rain gauge for

each 40 acres.• Recording rain gauge

cost $50 - $100

Water Quantity Needed• Irrigation water replaces the plant water use (removed

from soil)• Water use is directly correlated to light interception• 50% light interception results in about 50% of the

maximum water use• Maximum water use mid-July early August, full light

interception, highest temperatures brightest and longest days.

Evapotranspiration (ET) = fn (net radiation) +fn (temperature) +fn (wind speed) +fn (air humidity)

Weighing Lysimeter

Rain and Irrigation increase weightEvapotransporation decrease weight

Crop Water use curve

0

0.05

0.1

0.15

0.2

0.25

0.3

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

Weeks after emergence

Wat

er u

se (i

nche

s)

Series1

Series2

Series3

Series4

Series5

Field beans Soys

Corn

Alfalfa

Field beans

Corn

Soys

Potato

Alfalfa

From Minnesota Extension bulletin “Irrigation Scheduling”, assuming temperature 80-89

1. Irrigation Runoff (comparing irrigation application rate to soil infiltration rate) 0 -30 % loss

3. Evaporative loss to the air•Minimal loss in our humid area•0 – 6%•Estimated 4-6% loss in Nebraska


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Can

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(ml)



2. Lack of system uniformity• 5-35% loss in effectivenessThree factor

reducing effective water application

Average application efficiency

Inches of application

70% 80% 90%

0.5” .35 .40 .45

0.6” .42 .48 .54

0.7” .49 .56 .63

0.8” .56 .64 .72

0.9” .63 .72 .81

1.0” .70 .80 .90

1.1” .77 .88 .99

1.2” .84 .96 1.08

1.3” .91 1.04 1.17

Net application at various application rates

Necessary application rate to achieve effective evapo-transportation rates at various application efficiencies

Average application efficiency

Desired Inches of effective application 70% 75% 80% 85% 90% 95%

0.16 0.21 0.20 0.19 0.18 0.18 0.17

0.18 0.23 0.23 0.22 0.21 0.20 0.19

0.20 0.26 0.25 0.24 0.23 0.22 0.21

0.22 0.29 0.28 0.26 0.25 0.24 0.23

0.24 0.31 0.30 0.29 0.28 0.26 0.25

0.26 0.34 0.33 0.31 0.30 0.29 0.27

0.28 0.36 0.35 0.34 0.32 0.31 0.290.30 0.39 0.38 0.36 0.35 0.33 0.320.32 0.42 0.40 0.38 0.37 0.35 0.34

Quantity Needed

• Maximum water use for most crops is .27 - .32 in./day

• 3 gal/minute/acre pump capacity = 1”/week

• 5 gal/minute/acre pump capacity = .25 in./day

• 7 gal/minute/acre pump capacity =.33 in./day, 1”every 3 days

• 500 gal/minute pump can provide 1” every 4 days on 100 acres

Quantity NeededIn a hot 1st week of August John’s corn crop ET. was .30 in./dayJohn’s field has a AWC of 3.0 in. (Available water capacity)

He started irrigating when the AWC was 1.0 in. down

John’s irrigation system can apply .20 in./day.

By the end of the week how far behind is John? (.30 -.20)x7 =.70 in.

During 2nd week of August, ET. remains .30 in./day, John shuts down 2 days for repair. By week end how far behind is John?

(.5 +.6)= 1.1in. 2.80 in. total deficit 3rd. Week, no rain, John’s corn field is hurting.

Limited water supply irrigation management

• Diversify the crops sharing the water supply between high and low water use.

• Stager planting date to stager peak water need times.

• Plant part of irrigated area to a sacrifice crop to neglect during extended drought.

• Start irrigating early to bank water ahead.• Stager forage crop cutting dates to avoid

simultaneous peak use.

1109’

1320’

Field #10

20 acres

20 acres

30 acres

30 acres

Crop Water use curve

0

0.05

0.1

0.15

0.2

0.25

0.3

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

Weeks after emergence

Wat

er u

se (i

nche

s)

Series1

Series2

Series3

Series4

Series5

Field beans Soys

Corn

Alfalfa

Field beans

Corn

Soys

Potato

Alfalfa

From Minnesota Extension bulletin “Irrigation Scheduling”, assuming temperature 80-89

Irrigation Scheduling Checkbook Method –University of Minnesota

• Items to Conduct Checkbook Irrigation Scheduling

o Two or more rain gauges o Max-Min thermometer or access to local

temperature reports o Soil probe or in field moisture sensors o Daily crop water use table or local ET hotline or

website report o Soil water balance worksheets o Estimate of soil moisture holding capacity

Jun 21Jun 22Jun 23Jun 24Jun 25Jun 26

757585757575

.17

.17

.20

.20

.17

.17

501.5

3.0

-0--0--0--0--0--0-

2.232.061.891.691.492.071.90

0.75

Frasier 60”SW 1/4

30”


757585757575

.17

.17

.20

.20

.17

.17

501.5

3.0

-0--0--0--0--0--0-

2.232.061.891.691.492.071.90

0.75

Frasier 60”SW 1/4

30”

0.770.941.111.311.510.931.10


757585857575

.15

.15

.18

.18

.15

.15

501.5

3.0

-0--0--0--0--0--0-

2.001.851.701.521.341.941.79

0.75

corn 6-1-08SW 1/4

36”

Available

Table 9. Average water use for any other crops when at full canopy at different times of the season

Daily highTemp

May1

2 3 4 Jun5

6 7 8 Jul9

10 11 12 Aug13

14 15 16 Sep17

50-59 .06 .07 .07 .08 .08 .08 09 .09 09 09 09 .08 .08 .08 07 .07 06

60-69 .09 .10 .11 .11 .12 .12 .13 .13 .13 .13 .13 .12 .12 .12 .11 .10 .09

70-79 .12 .14 .14 .15 .15 .15 .17 .17 .17 .17 .17 .16 .16 .16 .14 .13 .12

80-89 .15 .17 .18 .18 .19 .19 .20 .20 .21 .21 .21 .20 .20 .20 .17 .16 .15

90-99 .18 .20 .21 .22 .22 .22 .24 .24 .25 .25 .25 .24 .24 .23 .21 .19 .18

Source: Data estimates full potential of daily ET per week by Killen, and was placed in the above table by Wright in January 2002.

www.agry.purdue.edu/irrigation/IrrDown.htm

MichIana Irrigation Scheduler: Purdue Agronomy web site –Est. From High / Low temp. & date

Date- July 1Stage/

ET.Estimate

July 2Stage/

ET.Estimate

July 3Stage/

ET.Estimate

July 4Stage/

ET.Estimate

July 5Stage/

ET.Estimate

July 6Stage/

ET.Estimate

CornEmerged

May 1.19

1st. Tassel.20 .20 .20 .20

full tassel.22

CornEmerged

May 7.17

10 leaf.17 .19 .19 .19

1st. Tassel.20

CornEmerged

May 14.15

8 leaf.15 .15 .16

.16

10 leaf.17

SoybeanEmerged

May 7

6th. Trifolliate.18

.18 .18 .20 .20

First flower.21

SoybeanEmerged

May 14

4th. Trifolliate.15

.16 .16 .16 .18

6th. Trifolliate

.18

Grass -reference

crop

4” standard.17

4” standard .20

4” standard .17

4” standard .20

4” standard .20

4” standard .20

Mendon Estimated Evapotranspiration (ET) for July 4, 2008Irrigation scheduling links:•Historical E.T. for this site•MSU Scheduler IS 4•MichIana Irrigation Scheduler•MSU Scheduler Excel•MSU Paper check book system

Explanation of estimated E.T..Corn – 105 day maturity emerging on the listed date in 30” rows.Soybean – for grow 3.0 emerging on the listed date.E.T. have been estimate for two days in the future based on future weather forecast.

Irrigation Scheduling Checkbook Challenges

Errors will accumulate over time - Weekly ground truthing needed

Rainfall variability is more than often considered

Only "effective” rainfall and irrigation should be considered - Only water entering root zone uniformly is "effective”

Corn crop mature in program by calendar, not heat

?? Soil Moisture ??


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Catch Can Volume (ml)Tower

1Tower

3Tower

5Tower

7 Tower 8


WWW.msue.msu.edu/St Joe /Irrigation

http://www.msue.msu.edu/St%20Joe%20/

Water supply over or under designsupply over design yield tail up, supply under design yield tail down

Example of water supply under volume for sprinkler design

165’

825’

1320’1155’


495’

660’

990’

2 acres

18 acres31 acres

49 acres

71 acres

96 acres126acres

10 acres

13 acres

18 acres

22 acres

25 acres

30 acres

Total Acres

Feet from center

4145’3109’

2072’

5181’6217’

7253’8290’

circumference

Over and under

application issue affect the majority

of the application

area

Most system apply within 85% of the expected application

Application is 4 %

under expectation

Measure flow at desired pressure prior to ordering sprinkler package

Poor performance:

Ask dealer to measure flow at peak water use season and compare to design parameters.

Assure the best plant stand

possible

• Irrigate, if necessary, to make sure to get maximum germination and uniform emergence.

• Wet down 2.5” within five days of planting, ½” in most irrigated soil

• Maintain a moist surface,0.10” to 0.20” applications, till spike.

• Are you ready to irrigate the day you plant?

Using irrigation to get the most from pesticides and nutrients

Timely application of irrigation water:• Improves incorporation of herbicides. • Improves activation of herbicides. • Improves activation/reactivation of

insecticides.

• Reduces nitrogen volatilization.• Maximizes yield to utilize the resources.

• Do not apply this product through any type of irrigation system.

• If available, sprinkler irrigate within 2 days after application. Apply ½” -1” of water. Use lower water volumes (½” ) on coarse-textured soils, higher volumes heavier soils (1”) on fine-textured soils.

Chemigation – Application of pesticide via irrigation water.

Fertigation – Application of fertilizer via irrigation water.

Chemigation Label

• Chemigation labels provide specific mixing application and safety precautions for irrigation applications.

• EPA requires products applied through irrigation systems to have a chemigation label.

Calibrating a Center Pivot for Chemigation

Chemigation Valve Requirements

Indiana and Michigan have specific chemigation valve requirements for public water supply connections but not for private water supplies.

Both States require adequate protection of water supply in law or well code.

Most chemigation valves consist of:

4 inch inspection port

injection port for introducing the chemicals

air and vacuum relief valve

spring-loaded check valve

a low pressure drainFlow direction

Chemigation / Fertigation Systems - Safety Interlock

Backflow protection (chemigation valve)

Positive displacement injection pump

Injection nozzle with back flow protection

Storage / mixing tank

High Pressure hose (injection hose, 160 psi)

Supply hose (sized to gravity flow needed volume to pump)

Backflow situation – What do I do?

Pump, Pump, Pump as soon as possible.

Nebraska study showed 990/1000 gallon recovery in the first hour when pumping started immediately.

• 999/1000 gallon after the first day of pumping.• 99.9% one day pumping recovery is reduced 10-

20% if you start 24 hour later.

Equip Groundwater Conservation Program

An NRCS Program to support Irrigation System Evaluations and

System Corrections

Equip Groundwater Conservation Program - Michigan

• Qualifications– System must have been in place for at least 2 years– Must use irrigation scheduling (Computerized or

Paper System)– System uniformity coefficient must be below 85% to

enter, and above 85% to qualify for payments.– Need to have an irrigation conservation plan

• Write up that describes system, water source, how the irrigation is applied,

2009 EQIP Groundwater Conservation Program - Michigan

• Compensation:– A one time payment of $31/acre. (down from $50)– ( was a maximum of 160 acres per producer )– Scheduling is required annual payment of $11.40/acre

(up from $5)

– See you local NRCS office.

irrigation management practices

Documents

irrigation buttonthanks

irrigation uniformity

irrigation application

irrigation application

inch of irrigation waterday

years of increasing

visible system leaks

application area