Analysis on field water balance and water-saving irrigation modes in Chanzhi Reservior irrigation area

This paper establishes soil water movement model of typical farmland in Chanzhi Reservior irrigation area based on long-time field experiment. The results indicate that leakage of soil water is almost serious under conventional irrigation mode, precipitation and irrigation show positive correlation with water leakage and field evapotranspiration. Water-saving irrigation modes under the condition of different hydrographic years were simulated based on soil water adjustment criterion, in contrast with conventional irrigation, it could save water 240 mm in wet year, 140 mm in medium precipitation year, and 90 mm in draught year, respectively. Simultaneity, the amounts of water leakage under water-saving irrigation modes are significantly less than conventional irrigation, the leakage intensities of wet year, medium precipitation year, and draught year decrease by 0.66, 0.35 and 0.27 mm/d, respectively. Due to the reasonable control of irrigation in the key growth stages of crop, the amount of water leakage decreases while meeting water requirement for crop. So it can improve the utilization efficiency of irrigation water.