中文摘要：

干旱农业区采用覆膜滴灌技术，在无覆膜的膜间裸露区内设置排盐浅沟，探讨不同灌水定额和不同排盐梯度条件下，覆膜滴灌土壤盐分定向运移和盐分上移地表排盐效果。研究结果表明，膜下滴灌定向排盐效果明显，滴头附近形成盐分淡化区域，排盐沟周边形成盐分集中区域。地表以下O-60cm平均土壤盐分普遍呈现膜下的盐分低于膜外，而膜外裸露区积盐作用显著的特点。灌溉用水量愈大，排盐作用愈强烈，相应的积盐数量也愈大。通过农田排盐沟灌水冲洗后的地表排水矿化度随时间呈减小趋势，排盐梯度最小的试验小区冲洗排盐量最大。总体来说，在排盐沟冲洗定额1515m^3／hm^3条件下，各小区总排盐量达到4521—635 lkg／hm^2，表明盐分上移地表排的脱盐效果显著。

英文摘要：

The effect of directional soil salt transport and surface salt-removing were studied under differ-ent irrigation quota and salt draining gradient in arid agricultural areas where the mulched drip irrigation was adopted and shallow salt draining ditch was arranged within uncovered area. The results show that the effect of directional salt transport under mulched drip irrigation is obvious. There are the desahed zone near-by the emitter and salt accumulation zone nearby salt draining ditch. The average soil salt in 0-60cm soil layer is characterized by lower soil salt below plastic film mulch and salt accumulation out of plastic film mulch. The more irrigation water amount is, the stronger salt-removing effect will be and the greater salt accumulation amount will be. The surface drainage salinity shows a decrease trend over time after the irriga- tion flushing of salt draining ditch, and salt-removing amount was the biggest at the test plot with the smallest salt draining gradient. In general, under 1 515m^3/hm^2 of salt draining ditch leaching quota, total salt-removing amount reached 4 521-6 351kg/hm^2, indicating that the salt up and surface salt-removing ef- fect was remarkable.