Irrigation

Cost share for irrigation system upgrades will be available starting early 2022 for irrigation systems located within Becker, Benton, Cass, Dakota, Douglas, East Otter Tail, Grant, Hubbard, Kandiyohi, Meeker, Morrison, Pope, Sherburne, Stearns, Stevens, Swift, Todd, Wadena, Washington and West Otter Tail Soil and Water Conservation Districts (SWCD).

The program provides financial and technical support to irrigators looking to adopt and integrate proven precision irrigation technology and nitrogen management practices to help optimize irrigation system operation. This will help address groundwater quality and quantity issues under irrigated cropland. In addition to providing cost share, a limited number of irrigators will receive a stipend to participate in the AgCentric Farm Business Management Program to provide an annual financial analysis of their operation.

The cost share is available through a $3.5 million agreement with the USDA-Natural Resource Conservation Service (NRCS). The Minnesota Department of Agriculture (MDA), NRCS, University of Minnesota, the SWCDs listed above, Central Lakes College, AgCentric, Mille Lacs Band of Ojibwe, state agencies, irrigator’s associations, and businesses have partnered to offer this program.

More information at https://www.agcentric.org/rcpp-precision-irrigation/

This project will promote responsible use of Minnesota’s limited groundwater resources through the expansion of the existing Irrigation Management Assistance tool into a statewide, mobile-compatible web app covering the agricultural areas of the state. This project will improve irrigation scheduling to both enhance farmer yields and reduce environmental impacts. It will do this by developing and deploying a suite of low-cost sensors coupled with process-guided machine learning techniques to predict crop water requirements.

We hypothesize that process-guided machine learning techniques will perform better than the current state-of-the-art irrigation scheduling approaches when evaluated against empirical measures. We also hypothesize that improved predictive accuracy will increase users’ trust in the Irrigation Management Assistant tool in order to support broader adoption and use across the state. The final results are anticipated to be both novel machine learning methods for improved irrigation management, a user study of how the machine learning methods impacted tool usefulness for farmers, and the release of the tool for statewide on-farm use, supported by extensive education and outreach activities.

At this time, the Irrigation management assistant  (IMA) is available for Benton, Otter Tail, Becker, Hubbard, Wadena and Todd Counties of Minnesota. Additional expansion information will be available soon. 

The  Minnesota Irrigator Program (MIP) is an educational program focused on providing advanced training on irrigation water management, irrigation system and equipment maintenance, energy conservation, water conservation and quality, and the economics of irrigated agriculture. MIP includes classroom training, peer-to-peer exchange of information between producers, and field demonstrations.

Learn more about the program

Benefits of an irrigation scheduling program

A sound irrigation scheduling program can help an operator:

• Prevent economic yield losses due to moisture stress.
• Maximize efficiency of production inputs.
• Minimize leaching potential of nitrates and other agrichemicals below the rooting zone.
• Conserve the water resource and maximize its beneficial use.

Follow these steps

To set up and operate an effective irrigation scheduling program these sequenced procedures need to be followed for each field:

1. Determine the crop's active rooting depth and the corresponding available water-holding capacity for each soil type in the field.
2. Select the predominant soil type(s) that should be used for irrigation water management purposes.
3. Define the management allowable soil water depletion (MAD) limits for the selected soil types and the crop(s) to be grown.
4. Establish a soil moisture monitoring system and regularly (at least twice a week) keep track of the soil water deficit or depletion.
5. Initiate an irrigation when the soil water deficit is expected to approach the selected management allowable soil water depletion limit by the time the irrigation cycle is completed.

What you'll find here

A brief discussion of basics and methods of irrigation scheduling is presented in this section. This procedure typically takes 5 to 20 minutes of the operator's time daily to keep updated after determining the initial soil water characteristics. If operator time is not available to regularly monitor and estimate the soil moisture, consider finding a crop consultant to assist in achieving the management objectives and adopting advanced cellular telemetry irrigation management options that are available in the market.

Basics of irrigation scheduling

Learn about the different components of the soil water reservoir and how soil texture affects water-holding capacity (AWC).  

Soil moisture sensors for irrigation scheduling

• Types of soil moisture sensors and how they work
• How to install and place sensors
• Example calculations

Evapotranspiration-based irrigation scheduling or water-balance method

The evapotranspiration-based or water balance method uses weather data to account for soil-water in the rooting depth.  Learn how to account for inputs and outputs: 

• Estimate initial soil moisture.
• Estimate crop water use.
• Use an ET gauge to estimate crop evapotranspiration.

Estimating soil moisture by feel method

Step-by step instructions for estimating soil water deficit based on soil feel and appearance.

Irrigation scheduling checkbook method 

The checkbook method of scheduling enables you to monitor a field's daily soil water balance (in terms of inches of soil water deficit), which can be used to plan the next irrigation. This method requires you to

• Monitor the growth of the crop.
• Observe the daily maximum air temperature.
• Select the daily evapotranspiration (ET) estimation from the crop water use table.
• Measure the rainfall or irrigation applied to the field.
• Calculate the new soil water deficit balance.

To calculate the new soil water deficit and keep a record of daily changes, enter the data into the soil water balance sheet. 

Irrigation management assistant  (IMA)

The Irrigation management assistant is automated software that works on the principles of water balance irrigation scheduling method as described in links above. At this time, the tool is available for Benton, Otter Tail, Becker, Hubbard, Wadena and Todd Counties of Minnesota.

Irrigation management strategies

Deciding when to irrigate is a daily decision that depends on many changing factors. Learn how to adjust irrigation

• By season/growth stage
• Predicting the last irrigation
• When you change the allowable soil water deficit
• Pumping capacity

Application uniformity testing for center pivot irrigation systems  explains how to:

• Conduct each of the steps in a uniformity test
• Use the Worksheet for uniformity testing (XLSX).
• Understand the uniformity coefficient (CU_H)
• Interpret the results and determine whether or not you need to take additional steps 

Watch the video to see a test being performed

Applying nitrogen with irrigation water

• Basics of fertigation
• Irrigation systems
• Nitrogen sources, timing and rates
• Calibration
• Management tips 

Chemigation safety measures

The greatest risk of chemigation is the potential for accidental backflow of all or part of the chemical into the irrigation water source if the system is not properly set up, operated and maintained.

Pollution prevention devices

Do I need secondary containment for my fertigation tank? 

Inspecting your chemigation system

NDAWN Center

The North Dakota Agricultural Weather Network includes several locations in central and northwestern Minnesota. Weather data includes air and soil temperatures, evapotranspiration, wind speed and more.

Agricultural and horticultural decision support tools for Minnesota

Resources from MDA include growing degree day (GDD) tools, temperature, freeze/frost dates, evapotranspiration, soil temperature, and weather data from the around Minnesota.

Observed precipitation (National Weather Service)

Select a time period and location for precipitation data.

Water resources from MN DNR

• Well permits
• Irrigation permits
• Groundwater management program