Impacts of water management strategies on soil water-salt movement

Based on the data obtained from field observation and experiment laboratory in the Yonglian plot of Yichang Irrigated District in Hetao Irrigation Area,Inner Mongolia,China,statistical models,MODFLOW-SURFACT,MODFLOW,MT3DMS and Reservoir Leaching Model were used to simulate the variable saturated soil water-salt dynamics.The impacts of water management strategies on water-salt dynamics were evaluated.The results show that when irrigation application decreased to 87% of the original water due to channel leak prevention,the salt accumulation in the plot was about the same with the original case.Meanwhile,the salt accumulation in upper layer soil decreased to 89%,groundwater mineralization was much higher than before,and the average water table of arable land was too deep to support crop growth.When irrigation application decreased to 76% of the original water due to autumnal irrigation quota reduced to 1 500m3/hm2,the salt accumulation in the plot was about 88% of the original case.Meanwhile,the salt accumulation in upper layer soil decreased to 94%.The average water table of arable land was suitable for crop growth.Thus,the mitigation of salt accumulation and great efficiency of water resource application attributed to appropriate water management,while,blindly reducing of water resource brought on excessive salt accumulation and reduction of output.