MANAGING Tough Times

Irrigation 101

Maximizing the value of Irrigation

Kris Kohl

ISU Extension

Ag Engineer

MANAGING Tough Times

Irrigation 101

Managing a Runoff Basin

Dictated by pond level Applied on wet soil Light as possible to reduce negative impact

MANAGING Tough Times

Irrigation 101

Managing pond level

• Dictated by crop need• Determining crop need• Evapotranspiration (water use)

• Temperature and Humidity• Growth stage of the crop

MANAGING Tough Times

Irrigation 101

How can we improve our skills

• Measure the nitrogen level in pond

• Apply water so that we don’t saturate soil

• Measure water use from crop

• Measure yield at end of year

MANAGING Tough Times

Irrigation 101

Water use CornInches per day

Month 50-59 60-69 70-79 80-89 90-99

May .07 .13 .19 .23 .27

June .09 .15 .21 .25 .29

July .09 .15 .22 .26 .30

August .08 .13 .18 .22 .26

September .07 .10 .13 .17 .20

MANAGING Tough Times

Irrigation 101

Check Book Method

Date Rainfall And Irrigation Inch

Crop use (ET)inch

Balance

May 4.18 5.89 10.00

June 5.11 7.20 7.91

July 4.64 8.06 4.49

Aug 3.49 7.5 0.48

MANAGING Tough Times

Irrigation 101

Check Book Method

Date Rainfall And Irrigation Inch

Crop use (ET)inch

Balance

May 4.18 5.89 10.00

June 5.11 7.20 7.91

July 4.64 + 2.51 8.06 7.00

Aug 3.49 + 4.01 7.5 7.00

MANAGING Tough Times

Irrigation 101

Check Book Method Goals

• Optimize crop yields

• Never allow the soil moisture balance to go below 6 inches

• Prevent runoff

MANAGING Tough Times

Irrigation 101

Gated pipe layout

MANAGING Tough Times

Irrigation 101

Offer

• Collect sample in June

• Determine water use from weather.com site every 2 weeks starting June 1

• 2 site visits during application

• Yield check

• Cost -$150