Drip irrigation under plastic mulch has been widely applied in arid Northwest China as a water-saving irrigation technology. A comprehensive knowledge of the distribution and movement of soil water in root zone is ess...Drip irrigation under plastic mulch has been widely applied in arid Northwest China as a water-saving irrigation technology. A comprehensive knowledge of the distribution and movement of soil water in root zone is essential for the design and management of irrigation regimes. Simulation models have been proved to be efficient methods for this purpose. In this study, the numerical model Hydrus-2D was used to simulate the temporal variations of soil water content in a drip irrigated cotton field under mulching. A concept of partitioning coefficient, calibrated to be 0.07, was introduced to describe the effect of plastic mulch on prevention of evaporation. The soil hydraulic parameters were optimized by inverse solution using the field data. At the optimized conditions, the model was used to predict soil water content for four field treatments. The agreements between the predictions and observations were evaluated using coefficient of determination （R2） and root mean square error （RMSE）. The results suggested that the model fairly reproduced the variations in soil water content at all locations in four treatments, with R2 ranging from 0.582 to 0.826 and RMSE from 0.029 to 0.050 cm3 cm-3, indicating that the simulations agreed well with the observations.展开更多
基金Supported by the Special Fund of Industrial(Agriculture) Research for Public Welfare of China(No.200903001)the Special Fund of Industrial(Marine) Research for Public Welfare of China(Nos.201105020-3 and 201105020-4)+2 种基金the Jiangsu Provincial Science and Technology Support Program,China(No.BE2010313)the Knowledge Innovation Program of the Chinese Academy of Sciences(No.KZCX2-YW-359)the National Natural Science Foundation of China(No.41171181)
文摘Drip irrigation under plastic mulch has been widely applied in arid Northwest China as a water-saving irrigation technology. A comprehensive knowledge of the distribution and movement of soil water in root zone is essential for the design and management of irrigation regimes. Simulation models have been proved to be efficient methods for this purpose. In this study, the numerical model Hydrus-2D was used to simulate the temporal variations of soil water content in a drip irrigated cotton field under mulching. A concept of partitioning coefficient, calibrated to be 0.07, was introduced to describe the effect of plastic mulch on prevention of evaporation. The soil hydraulic parameters were optimized by inverse solution using the field data. At the optimized conditions, the model was used to predict soil water content for four field treatments. The agreements between the predictions and observations were evaluated using coefficient of determination （R2） and root mean square error （RMSE）. The results suggested that the model fairly reproduced the variations in soil water content at all locations in four treatments, with R2 ranging from 0.582 to 0.826 and RMSE from 0.029 to 0.050 cm3 cm-3, indicating that the simulations agreed well with the observations.
