Strategies to Minimize Water Consumption while Maintaining Productivity in Uruguayan Rice Production

Abstract

Water is a limiting factor for the expansion of rice crop in Uruguay. During the seasons 2010-2011, 2011-2012 and 2012-2013 the effect of different irrigation management alternatives during the vegetative stage of rice on yield and water use were evaluated. The objective of this study was to improve water use efficiency and increase crop water productivity. Three continuous flooding treatments: flooding 15, 30 (control) and 45 days after emergence (CF15, CF30 and CF45), and two controlled irrigation treatments: intermittent irrigation (II) and alternate wetting and drying (AWD) were evaluated. Higher yields were obtained in treatments CF15, CF30 and II (10592, 10454 y 10189 kg ha^-1, respectively), followed by CF45 and AWD (9653 y 9287 kg ha^-1, respectively). AWD treatment had the lowest irrigation water use (6568 m3 ha^-1). Mean irrigation water productivity ranged from 1.18 (CF45) to 1.46 kg m^-3 (AWD). This study demonstrates that there are irrigation strategies that can significantly reduce irrigation water use while reaching high water productivity values. However, the yields obtained determine the need to deepen the studies in controlled irrigation alternatives, so that the water restrictions generated do not imply a decrease in crop productivity.