咸水灌溉对塔里木沙漠公路防护林外缘土壤水盐环境的影响

Impacts of Saline Water Irrigation on Soil Water-salt Environment of Outer Edge of Tarim Desert Highway

为了更好地维持塔里木沙漠公路防护林的可持续性,监测了在现有灌水制度一个完整灌水周期内防护林外缘土壤水盐环境的变化。研究结果表明:(1)林带外缘的土壤含水量在灌水结束后开始减少,在灌水周期的第6d林带外缘90cm范围内的土壤水分逐渐的减小,大于90cm的范围达到基本平衡;(2)在咸水灌水淋洗和蒸散等因素的综合影响下,防护林带外缘土壤盐分表现出向林带外120cm土壤层和表层聚积,根系层土壤有所减少;(3)防护林外缘地下水盐分相对变化表现出"V"型变化,在距林带90cm处变化最弱,地下水各参数距离林带越近变化越大。

In order to maintain the sustainability of Tarim Desert Highway shelterbelts,the change of soil water-salt environment of the outer edge of the shelterbelts in a complete irrigation cycle was monitored.Results showed that（1）soil water content on the outer edge of the shelterbelts began to decline when irrigation finished.After the sixth day in the irrigation cycle,it gradually decreased within 90 cm outside of the outer edge and reached a basic balance beyond 90 cm outside of the edge.（2）Because of a comprehensive influence of saline water irrigation and evapotranspiration,soil salt outside of the edge was accumulated in soil surface and 120 cm soil layer and the accumulation decreased in root layer.（3）The relative change of slat content in groundwater on the outer edge presented a V-type change and the change was the weakest 90 cm outside of the edge.Groundwater parameters had a greater change with decreased distance to shelterbelts.