Saline water irrigation management for spring wheat in theYellow River Irrigation District of Ningxia

In order to investigate the best irrigation management mode with saline water for spring wheat in the Yellow River irrigation district of Ningxia, the SWAP model was calibrated and validated with the experimental data carried out in 2007, then the model was applied to evaluate the saline water irrigation scheduling for the experimental year and different hydrological years. Calibration and validation results indicated that the simulated soil water content, salt concentration and crop growth indices were in good consistent with the measured data. Results implied that the model had been well calibrated and validated, and the model could be used as a management tool to evaluate the effects of various irrigation management practices on water and solute dynamics and crop yield. The simulated results indicated that the optimal irrigation management practice of spring wheat was to irrigate the field with four times of mixed irrigation (1:1 saline and fresh water) at total amount of 2 400 m3/hm2 for the experimental year. The optimal irrigation practices of spring wheat for the hydrologic years of 75% and 50% were four times of mixed irrigation each for pre-sowing, jointing, heading and filling stages with total irrigation amount of 3 000 m3/hm2 and 2 300 m3/hm2, respectively. And for the hydrologic year of 25%, application of two times of mixed irrigation each for jointing and heading stages with total amount of 2 000 m3/hm2 was the optimal saline water irrigation practice of spring wheat. The optimal irrigation mode has guiding significance to effective irrigation of saline water in Yellow River Irrigation District.