Field irrigation experiments were conducted in the Hetao Irrigation District of Inner Mongolia,China,to study the effects of irrigation regimes on salt leaching in the soil profile.The data were used to calibrate and ...Field irrigation experiments were conducted in the Hetao Irrigation District of Inner Mongolia,China,to study the effects of irrigation regimes on salt leaching in the soil profile.The data were used to calibrate and validate the HYDRUS-1D model.The results demonstrated that the model can accurately simulate the water and salt dynamics in the soil profile.The HYDRUS-1D model was then used to simulate 15 distinct irrigation scenarios.The results of the simulation indicated that irrigation amount did not have a significant effect on soil water storage but that increases in irrigation amount could accelerate salt leaching.However,when the irrigation amount was larger than 20 cm,the acceleration was not obvious.Compared with irrigating only once,intermittent irrigation had a better effect on increasing soil water storage and salt leaching,but excessive irrigation times and intervals did not improve salt leaching.In addition,we found that the irrigation regime of 20 cm,irrigated twice at 1-d intervals,might significantly increase salt leaching in the plough layer and decrease the risks of deep seepage and groundwater contamination.展开更多
连续3年对滨海盐土进行咸水结冰灌溉和地膜覆盖基础上的土壤水盐动态监测，并在以上基础上，针对不同地膜覆盖时间，设置了结冰灌溉条件下融冰入渗后覆膜（MI）、播种覆膜（SI）和无覆膜（NI），以及灌前秋季覆膜（无结冰灌溉，AN）和...连续3年对滨海盐土进行咸水结冰灌溉和地膜覆盖基础上的土壤水盐动态监测，并在以上基础上，针对不同地膜覆盖时间，设置了结冰灌溉条件下融冰入渗后覆膜（MI）、播种覆膜（SI）和无覆膜（NI），以及灌前秋季覆膜（无结冰灌溉，AN）和对照（无结冰灌溉无覆膜，CK）5个处理，以研究咸水结冰灌溉条件下土壤水盐动态规律，以及覆膜时期对土壤水盐动态和棉花生长的影响。结果表明：咸水结冰灌溉后，随着咸水冰层的融化，地表冰层含盐量和钠吸附比（SAR）均逐渐降低。相同土壤深度土壤含盐量随灌溉年限的延长而逐年降低，如2006—2008年冬灌前土壤表层（0～20 cm）盐分含量分别为19.8、15.4和12.4 g kg-1。结冰灌溉融水入渗完成后，0～40cm土层的土壤含盐量均被淋洗至4kg-1以下。融水入渗后9 d内进行地膜覆盖效果较好。咸水结冰灌溉结合地膜覆盖（MI）土壤脱盐效果最好，其棉花出苗率和籽棉产量也最高，分别为63.78%和3 200 kg hm-2，其次为AN、SI、NI和CK处理。经过长期（3年）结冰灌溉后，秋季进行覆膜依然可获得较高产量，其棉花出苗率和产量分别为59.63%和2 600 kg hm-2。但如果没有覆膜措施或覆膜较晚，依然不能获得理想的产量。展开更多
基金supported by the National"Twelfth Five-Year"Plan for Science & Technology Support Program(2011BAD25B07)the State Natural Science Fund(51279142)the Fundamental Research Fund for the Central Universities of the Ministry of Science and Technology,China.(2012206020206)
文摘Field irrigation experiments were conducted in the Hetao Irrigation District of Inner Mongolia,China,to study the effects of irrigation regimes on salt leaching in the soil profile.The data were used to calibrate and validate the HYDRUS-1D model.The results demonstrated that the model can accurately simulate the water and salt dynamics in the soil profile.The HYDRUS-1D model was then used to simulate 15 distinct irrigation scenarios.The results of the simulation indicated that irrigation amount did not have a significant effect on soil water storage but that increases in irrigation amount could accelerate salt leaching.However,when the irrigation amount was larger than 20 cm,the acceleration was not obvious.Compared with irrigating only once,intermittent irrigation had a better effect on increasing soil water storage and salt leaching,but excessive irrigation times and intervals did not improve salt leaching.In addition,we found that the irrigation regime of 20 cm,irrigated twice at 1-d intervals,might significantly increase salt leaching in the plough layer and decrease the risks of deep seepage and groundwater contamination.
文摘连续3年对滨海盐土进行咸水结冰灌溉和地膜覆盖基础上的土壤水盐动态监测，并在以上基础上，针对不同地膜覆盖时间，设置了结冰灌溉条件下融冰入渗后覆膜（MI）、播种覆膜（SI）和无覆膜（NI），以及灌前秋季覆膜（无结冰灌溉，AN）和对照（无结冰灌溉无覆膜，CK）5个处理，以研究咸水结冰灌溉条件下土壤水盐动态规律，以及覆膜时期对土壤水盐动态和棉花生长的影响。结果表明：咸水结冰灌溉后，随着咸水冰层的融化，地表冰层含盐量和钠吸附比（SAR）均逐渐降低。相同土壤深度土壤含盐量随灌溉年限的延长而逐年降低，如2006—2008年冬灌前土壤表层（0～20 cm）盐分含量分别为19.8、15.4和12.4 g kg-1。结冰灌溉融水入渗完成后，0～40cm土层的土壤含盐量均被淋洗至4kg-1以下。融水入渗后9 d内进行地膜覆盖效果较好。咸水结冰灌溉结合地膜覆盖（MI）土壤脱盐效果最好，其棉花出苗率和籽棉产量也最高，分别为63.78%和3 200 kg hm-2，其次为AN、SI、NI和CK处理。经过长期（3年）结冰灌溉后，秋季进行覆膜依然可获得较高产量，其棉花出苗率和产量分别为59.63%和2 600 kg hm-2。但如果没有覆膜措施或覆膜较晚，依然不能获得理想的产量。
