Teaching: Taking the E Out of ET.

Water is one of the major issues in Nebraska agriculture. It may even be our most important issue especially since we are now number one in irrigated farmland acres, having replaced California in 2007. We have water issues with Colorado and Kansas on the Republican River as well as declining groundwater levels in several areas. Cropping practices which can reduce ET (Evapotranspiration) in crop production will benefit Nebraska’s water situation. Research has shown that with 6,700 kg/ha of winter wheat residue, growing season evaporation for corn can be reduced from 35% on bare soil to 19% where the crop is irrigated twice weekly and from 32% to 15% if the crop is irrigated once a week (N.L. Klocke, 2004). Similar reductions are available with corn stover. These benefits along with how to manage crop residues are important issues which need to be conveyed to crop producers and others. “Clickers” have been used in presenting the message to the various audiences about how reducing the E in ET can benefit both rainfed and irrigated crop production in Nebraska. The presentation also includes the effect of long term no-till on water intake rates and the effect of controlled traffic. Reducing the E in ET can help us on the path to developing sustainable crop water use in Nebraska.