RICE CULTURE Effects of Water-Saving Rice Cultivation Methods on Yield, Water Use, and Water-Use Efficiency

Water available for irrigation is declining in many rice-growing regions around the world. Global populations continue to rise increasing crop production demand. Rice production systems must face the dilemma of maintaining or increasing yields with less water available to irrigate. Alternate wetting and drying (AWD) has shown to be an effective tool for water conservation in irrigated rice systems. Research on AWD practices is lacking and more information is needed to verify the success of AWD across varying soil types. More work is needed to develop clear recommendations for AWD irrigation practices in Arkansas. In this study we compared the effects of three different AWD regimes and a continuous flood management on rice yields and wateruse efficiency (WUE) from a conventional variety (RoyJ) and a hybrid (XL753). The study was located in the northeast corner of the Mississippi delta rice-growing region in Arkansas and results were complicated by a high rainfall pattern in 2014; even with this complication, results indicated that AWD is a feasible water management practice for rice in Arkansas. For both varieties, all AWD regimes tested in this experiment were associated with a loss in yield, the hybrid cultivar had a higher yield than the conventional variety in all treatments. Water-use efficiency for the wettest AWD treatment was higher than the conventional flood treatments and the dryer AWD treatments. Differences in WUE between varieties approached significance differences, and suggests that the hybrid may have a higher WUE than the conventional cultivar.