Authors

Abstract

To determine the optimal water-saving irrigation quota for summer maize in the salinized farmland of the Lupotan area (near Shaanxi Province, Northwest China), the parameters of the SWAP (Soil-Water-Atmosphere-Plant) model were calibrated and validated using field experimental data from 2018 to 2019. The results showed that the simulated values of soil water content, soil salt content, and summer maize yield were in good agreement with the measured values. Under different irrigation scenarios, soil water flux, cumulative soil water flux, soil salt flux, and cumulative soil salt flux at the lower boundary of the crop root zone and storage zone decreased with decreasing irrigation quota. When the irrigation quota was reduced to 70% IQ and 60% IQ, the changes in cumulative soil water flux and cumulative soil salt flux were small. Soil water could be stably stored in the 0–100 cm soil layer to meet the growth requirements of summer maize. When the irrigation quota was 3500 m3·ha-1 (70% IQ), the yield reduction of summer maize was less than 10%. Therefore, 3500 m3·ha-1 was identified as the optimal irrigation quota for summer maize from the perspective of soil water-salt flux and crop yield. The SWAP model can effectively simulate and predict soil water-salt transport and water-saving irrigation quotas for summer maize in salinized farmland. This study provides technical support for the efficient utilization of water resources and guidance for agricultural production practices in Northwest China.

Abstract in Chinese

为了寻求中国西北陕西省卤泊滩地区盐渍化农田夏玉米最优的节水灌溉定额，本研究基于2018年和2019年的田间野外试验资料，对SWAP (土壤-水-大气-植物)模型的参数进行了率定和验证。结果表明，土壤含水量、土壤含盐量和夏玉米产量的模型模拟值与实测值吻合较好。不同灌溉模拟情景下，作物根区和储水区下边界的土壤水分通量、土壤水分累计通量、土壤盐分通量和土壤盐分累计通量均随灌溉定额的减小而减小。当灌溉定额降低至70 % IQ和60 % IQ时，土壤水分累计通量和土壤盐分累计通量变化较小。土壤水分能够稳定储存在0~100 cm土层，以满足夏玉米生长的需求。当夏玉米灌溉定额为3500 m3·ha-1(70 % IQ)时，夏玉米减产幅度小于10 %。综合考虑土壤水盐通量和作物产量的变化，3500 m3·ha-1 为夏玉米最优的灌溉定额。SWAP模型能够较好地模拟和预测盐渍化农田夏玉米土壤水盐运移和节水灌溉定额。本研究旨在为中国西北地区水资源高效利用提供技术支撑，同时为中国西北地区农业生产实践提供指导。