Tillage Effects on Corn Water Use and Water Use Efficiency in a Sandy Loam Soil Under Irrigated Conditions.

Crop production with no-tillage has been increasing worldwide for several decades as producers seek to reduce input costs of conventional tillage practices. Few studies have reported the effects of various tillage practices and crop rotations on corn water use and water use efficiency. We hypothesized that no-tillage has a positive impact on corn and water use efficiency (WUE) in a 2-yr rotation compared to conventional tillage. A field study was conducted to evaluate and compare the effect of no-tillage (NT) and conventional tillage (CT) practices on water use (WU) and WUE of corn in a corn (Zea mays L.)-soybean (Glycine max L.) rotation on a sandy loam soil under overhead sprinkler irrigation system in the northern Great Plains. Tillage treatments were replicated five times in a randomized block design. Seasonal WU and WUE for corn were determined for the 2014 growing season according to the water balance and WUE equations under NT and CT practices. Results showed that corn grain yield was significantly lower in NT (6740 kg ha^-1) than in CT (7578 kg ha^-1). Corn yield differences due to tillage may have been associated with variations in soil water content, soil temperature, and plant population between NT and CT practices. Results also showed no significant differences between NT and CT for both corn WU (442, 462 mm) and WUE (15.3, 16.4 kg ha^-1 mm^-1), respectively.