It’s been an odd year. Dry, then lots of rain in later June, then dry again, then another extended rainy period, and now going dry again. Keeping irrigation systems going is time consuming, and costs you money for energy and repairs. But without the water, the crop yields can fall. So, when do you apply that final dose of water to your soybeans and corn?
First, I want to explain the term evapotranspiration, or ET for short. ET refers to the amount of water that both evaporates from the soil and passes through the crop into the air. Soybean plants showing their first yellow pod will have ET of one-tenth of an inch per day for a day that reaches into the mid 80-degree temperatures. Corn at dent stage will have an ET of 0.14 inch per day for a day that reaches into the mid 80-degree temperatures.