Grain yield, milling quality, and irrigation water productivity of rice under reduced irrigation in the Chira Valley, Peru

Introduction Increasing water scarcity and climate change are driving the need for irrigation strategies that improve irrigation water productivity while maintaining rice ( Oryza sativa L.) productivity. This study evaluated whether reduced irrigation water inputs could improve irrigation water productivity without significantly affecting grain yield and quality under tropical arid conditions in the Chira Valley, Peru. Methods Field experiments were conducted in three site -season environments using a randomized complete block design comprising 48 experimental subplots, with six blocks at El Chira and three blocks at each of the Viviate and Ignacio Escudero sites. Four irrigation treatments were evaluated: 17 000 (T0), 15 000 (T1), 14 000 (T2), and 13 000 m 3 ha -1 (T3). Results Within the range of irrigation volumes evaluated, irrigation treatment did not significantly affect grain yield or most agronomic and milling-quality traits; however, a significant overall treatment effect was detected for grain width. Grain yield ranged from 11.19 to 11.81 t ha -1 , with no statistically significant differences among treatments. In contrast, irrigation water productivity increased as irrigation volume decreased, with T2 and T3 increasing irrigation water productivity by approximately 24% and 28%, respectively, compared with conventional irrigation. Crop performance also varied among site -season environments.