Analysis of Long-Term Crop Water Use Efficiency Under Different Management Practices in the Upper Midwest.

Improving water use efficiency (WUE) is critical for food production under increasing food demand and water scarcity. Extensive studies have been carried out to understand the factors affecting it. However, long-term crop WUEs under different management scenarios remain limited. We synthetized field data collected at the Kellogg Biological Station, Long Term Ecological Research site and coupled the analysis with the SALUS model to evaluate maize, wheat and soybean WUEs under conventional, no-tillage and reduced agronomic input systems in 1989-2014. The results showed that the WUE under the no-tillage system was higher than that under the other two systems. Our results showed that management factors that increased crop yield and/or decreased soil evaporation increased crop WUE.