In stating the obvious, a group of Extension educators noted, “We’re in a changing environment – the Midwest and the Northeast are getting more precipitation in winter and spring but hotter and drier summers.”

That’s why irrigation management and efficiency especially are so important as the hot summer months settle in.

Presented by Lyndon Kelley of Purdue/Michigan State Extension at the most recent Great Lakes Expo, information on the topic was shared with growers that came from research from Younsuk Dong, Ph.D., irrigation specialist in the Department of Biosystems & Agricultural Engineering at Michigan State, and Angie Gradiz and Brenden Kelley, MSU Extension water use efficiency and irrigation educators.

For those using center pivot irrigation, you need uniform water application for peak efficiency – and that means 90% of the water is actually going to the plants. (Lyndon Kelley said that number varies slightly, as growers should aim for 90% to 94% efficiency.)

The importance of checking irrigation system uniformity is essential because poor water distribution can result in over- and under-irrigated areas. Under-irrigation can reduce crop yield and grain quality; over-irrigation can cause runoff and leaching of water and nutrients below the root zone. “You never want too much water,” Lyndon said.

The biggest reason to check irrigation efficiency, though, is because low uniformity can negatively impact a farm’s net return and environmental impacts.

Beyond your own system’s efficiency, there are some other options to consider when figuring out how much water your crops require.

First, find out what the water-holding capacity your acreage has by using soil sampling. Remember that the top eight inches of soil holds about 70% of available water.

You can visit websoilsurvey.sc.egov.usda.gov for a mapping tool that can also predict the water-holding capacity of your soil.

Also take into account the amount of potential evapotranspiration by visiting weather.gov/ict/evapotranspiration.

Lyndon Kelley then suggested growers also look at weather-based irrigation scheduling or sensor-based irrigation scheduling.

One sensor he mentioned specifically is a soil tension sensor. These measure actual soil water tension, which indicates the effort required by root systems to extract water from the soil. It’s nothing new – he noted this technology has been around since the 1970s. It’s a great example of “If it ain’t broke it, don’t fix it.”

“Whatever scale you’re at, creating efficiencies will always create rewards,” Lyndon concluded.

Want to check out some new tools? He mentioned MSU has an irrigation scheduler app (search for “IrrigMSU”).

For more resources form MSU Extension, you can also visit canr.msu.edu/irrigation.