Pivot irrigation system. Photo courtesy USDA NRCS.
Irrigation water management primarily aims to control the volume and frequency of irrigation water applied to crops, so as to meet crop needs while conserving water resources. Competition for water resources for agricultural and other uses is increasing—even in states like Minnesota that have abundant water. This makes it all the more essential to use irrigation water as efficiently as possible.
While Minnesota has less irrigated cropland than dryer states to its west, irrigation is not uncommon in areas of the state with sandy soils or lower total rainfall. Generally, average annual precipitation decreases from east to west across Minnesota, making irrigation more common in the western part of the state.
Irrigation water management involves an array of methods to reduce water use. In Minnesota, where sprinkler irrigation is common, a key method of reducing water use is to retrofit or replace center-pivot or other sprinkler systems with low-pressure sprinkler equipment. Reducing irrigation water use entails more than a change in equipment, however. Irrigating crops only when and where needed requires measuring or estimating how much water crops need at different stages of growth and how long it takes the soil to absorb the right amount of water. Farmers and crop consultants must also be able to detect changes in water intake rates and decide when and how to compensate by adjusting the irrigation volume or schedule.
Another objective of irrigation management is to prevent irrigation-induced soil and water quality problems such as salinity, soil erosion or leaching of nutrients or pesticides into groundwater. Crop managers must understand the potential for these problems to occur and address them as needed.
Irrigation management also presents opportunities for energy savings associated with low-pressure sprinkler equipment and modern energy-efficient pumps. In short, it takes energy to supply irrigation water and, generally, the less water used, the more energy saved.
Guidance from USDA's Natural Resources Conservation Service
University of Minnesota Extension resources
National Center for Appropriate Technology resources
University of Illinois
See contacts for specific programs that fund this practice in the side-by-side payment comparison or contact your local Soil and Water Conservation District