Optimizing Irrigation Strategies to Improve Water Use Efficiency of Cotton in Northwest China Using RZWQM2

Irrigated cotton (Gossypium hirsutum L.) is produced mainly in Northwest China, where groundwater heavily used. To alleviate water scarcity and increase regional economic benefits, a four-year (2016–2019) field experiment was conducted Qira Oasis, Xingjiang Province, to evaluate irrigation use efficiency (IWUE) production using the Root Zone Water Quality Model (RZWQM2), that calibrated validated volumetric soil content (?), temperature (Tsoil°) plant transpiration (T), along with growth yield data collected from full deficit experimental plots managed newly developed Decision Support System for Irrigation Scheduling (DSSIS). In validation phase, RZWQM2 adequately simulated (S) topsoil ? Tsoil°, as well (average index of agreement (IOA) > 0.76). Relative root mean squared error (RRMSE) percent bias (PBIAS) seed were 8% 2.5%, respectively, during calibration, 20% ?10.3% validation. The crop’s (M) T S (?18% < PBIAS 14% IOA 0.95) both fields. model subsequently run seven scenarios 850 350 mm (Irr850, Irr750, Irr700, Irr650, Irr550, Irr450, Irr350) long-term (1990–2019) weather determine best IWUE. Simulation results showed Irr650 treatment generated greatest (4.09 Mg ha?1) net income (US $3165 ha?1), while Irr550 achieved IWUE (6.53 kg ha?1 mm?1) (0.94 $ m?3). These provided farmers guidelines adopt strategies.