膜下滴灌水盐运移影响因素研究

通过室内盐碱土入渗模拟试验 ,探求了膜下滴灌滴头流量、灌水量、土壤初始含水量、土壤初始含盐量等因素对土壤水盐运移的影响。研究结果表明 :滴头流量的增加 ,地表积水范围增大 ,湿润体垂直距离减小 ,滴头附近的含水量增加 ,不利于作物正常生长的淡化区的形成 ;灌水量的增加使得湿润体的范围增加 ,同时有利于作物正常生长的淡化区的形成 ;土壤初始含水量增加 ,湿润体范围增大 ,滴头附近的含水量增加 ,但不利于作物正常生长的淡化区的形成和超过作物耐盐度的淡化区的发展 ;土壤初始含盐量的增加使得达标脱盐系数减小。这对合理利用膜下滴灌技术体系开发盐碱地提供一定的指导 ,有利于为滴灌系统的设计提供更合理的技术参数和进行膜下滴灌条件下的盐分管理。

FACTORS AFFECTING SOIL WATER MOVEMENT AND SOLUTE TRANSPORT FOR FILM DRIP IRRIGATION

Film drip irrigation, which combines advanced dripping irrigation with film planting, is able to provide good environment for crop growth and a new concept for dealing with water crisis and exploitation of salinized land. Laboratory infiltration simulation was conducted to study water movement and solute transport in film drip irrigation as affected by dripping rate, accumulated infiltration, initial soil moisture content, initial soil salt content etc. The results showed that water content around dripper increased with increasing dripping rate which deterred the formation of desalinization zone where crops can grow. Increase in accumulated infiltration increased the volume of wetted soil and favored the formation of desalinization zone. As initial soil water content increased the volume of wetted soil and water content around dripper also increased which inhibited the formation of desalinization zone. The increase in initial soil salt content would decrease the desalinization coefficient. The present study provided useful data for the design of film drip irrigation system and practical measurement for the utilization of salinized land.