The Difference in Water Use Efficiency Between Corn and Soybean

In the future, global population and temperature are predicted to increase, causing greater demand for water and increased competition between agriculture and other important sectors. One way to help meet this demand, is to identify strategies that increase water use efficiency (WUE) which is the ratio of crop production to water uptake. Improving WUE requires a baseline data in water dynamics. While there are lots of data comparing WUE for numerous crops and environments, research isolating evapotranspiration (ET) and WUE from all other environmental factors is limiting. To address this, we conducted a side-by-side evaluation of total ET and WUE of two major crops, maize (corn) and glycine max (soybeans), at a site in the U.S. Corn Belt. ET was determined using micrometeorological measurements, which were replicated for each crop and WUE was calculated using aboveground harvested biomass in the growing season of 2016. Average temperatures and precipitation were recorded slightly above climatological normal. Preliminary results suggest maize to be more productive and efficient in using water relative to glycine max.