Simulation of soil water-salt transport and crop growth in cotton fields under subsurface drainage conditions
To investigate the effects of subsurface drainage on mitigating secondary soil salinization and promoting crop growth in the downstream irrigation area of the Kizilsu River,a field experiment was conducted in Jiashi County,Xinjiang,from 2023 to 2024.Based on local conditions,12 orthogonal treatments were designed with drain depths of 1.2,1.4,1.6,and 1.8 m,and spacings of 40,30,and 20 m.The soil water and salt transport module and crop growth module of the SWAP model were calibrated and validated using observational data.Numerical simulations were then conducted on soil moisture and salinity distribution,crop LAI,and above-ground dry matter accumulation for the 12 subsurface drainage treatments.The results showed that the SWAP model effectively simulated water and salt transport dynamics under different treatments,with average RRMSE of 16.67%and 23.99%.The model had high accuracy in simulating moisture and salinity dynamics in the 0-60 cm surface layer,with average RRMSE of 14.46%and 22.28%,but lower accuracy in the 60-100 cm deeper layer,with average RRMSE of 18.71%and 29.04%.The model showed good consistency and accuracy in simulating cotton LAI and above-ground dry matter accumulation.Drain depth and spacing had significant effects(P<0.01)on the desalinization rate of the 0-100 cm soil layer,with a positive correlation to depth and a negative correlation to spacing.The study recommends a drain depth of 1.8 m and a spacing of 20 m as the optimal configuration for the region.
subsurface pipe drainagedrip irrigationSWAP modelwater and salt migrationcotton growth
万方数据
维普
