咸淡水交替淋溶下土壤盐分运移试验

Experimental study on salt movement in soil under saline and fresh water alternate leaching

为确定咸淡水交替灌溉后土壤盐分的运移规律,采用2 g/L,4 g/L两种矿化度的咸水分别与淡水连续、交替淋溶室内土柱,初步研究了咸淡水交替淋溶下土壤盐分的变化规律。研究结果表明:咸淡水交替淋溶下土壤表层盐分逐渐下移,两个试验处理的土柱都出现积盐情况,且4g/L时的积盐量大于2 g/L时的积盐量,土壤溶液中Na+,Ca2+的分布与EC值的变化规律基本一致,在此条件下盐分的增加没有引起土壤的碱化,灌水结束后,两个试验处理的土壤溶液EC值都小于4 dS/m,在作物耐盐的范围内,可推广应用到大田咸淡水交替灌溉中。

Laboratory tests were performed on alternate leaching of soil columns with fresh water and saline water at degree of mineralization of 2 g/L and 4 g/L respectively for preliminary research of the movement laws of salt in soil after saline and fresh water alternate irrigation. The result shows that the salt in soil gradually moves from the surface down toward the bottom under alternate leaching of saline and fresh water, and the salt accumulates in soil columns under the two test conditions, with more salt accumulated if saline water at degree of mineralization of 4g/L is adopted, and that the distributions of Na^＋ and Ca^2＋ as well as the variation of EC value in soft solution are almost the same under two test conditions. Under such test conditions, the increase of salt content in soil does not cause soil alkalinization, and the EC values of soil solution under the two irrigation conditions are both less than 4 dS/m after irrigation, which are within the range of salt tolerance of crops. Thus, the saline and fresh water alternate irrigation could be applied to fields for crop planting.