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Successive simulations of soil water-heat-salt transport in one whole year of agriculture after different mulching treatments and autumn irrigation
- Lu, Xinghang, Li, Ruiping, Shi, Haibin, Liang, Jiancai, Miao, Qingfeng, Fan, Leilei
- Geoderma 2019 v.344 pp. 99-107
- autumn, freeze-thaw cycles, irrigation, mulching, simulation models, soil depth, soil salinity, soil temperature, soil water content, straw mulches, water conservation, China
- In this study, the variation of the soil water-heat-salt transport for one whole year of agriculture under different mulching treatments and autumn irrigation in the Hetao Irrigation District of Inner Mongolia has been investigated and the best mulching treatment with the optimal mulching amount for this district have been determined. Based on field tests conducted between October 2013 and October 2015, the field test data of October 2013~October 2014 have been used to calibrate the SHAW model. After the calibration, the model has been used to simulate the soil water-heat-salt transport in the freezing-thawing and growth periods for one whole year of agriculture from October 2014 to October 2015. The accuracy of the model simulations were validated by comparing the simulated results with the field test data. Further, the calibrated SHAW model was used to simulate the process of soil water- salt transport for one whole year of agriculture from October 2015 to October 2016 to assess different mulching treatments. According to the results: ① the simulated soil temperature by the SHAW model is highly accurate, with increasing soil depth, RMSE decreases and NS approaches 1. For the simulated soil moisture content, the variations of the simulated and measured soil moisture contents are close to each other. For the simulated soil salinity, the analyses of the simulated and observed soil salinities show that the mean RMSE for the F0.9 treatment is 0.358 g/kg, and the mean NS is 0.813. Thus, the soil salinity simulation for the straw mulching F0.9 treatment is slightly better than that other treatment. ② Based on a comprehensive analysis on the simulated soil water-salt movement, the best mulching treatment for the Shahao Canal Test Station in the Hetao Irrigation District of Inner Mongolia is the straw mulching with 0.9kg/m2 mulching amount. The results of this study can be used as a theoretical basis and technical reference for the applications of water-saving autumn irrigation techniques in the Hetao Irrigation District of Inner Mongolia.