不同钠吸附比的咸水结冰融水入渗对苏打碱土的水盐运移影响

Effect of the Water and Salt Transport on Soda Alkaline Soil after Infiltration with Melting Ice Saline Water of Different SAR

利用不同水质(矿化度=10 g/L和SAR=5,10,30)、相同水量(678.2 ml)的咸水,进行了咸水结冰融水和咸水(不结冰)入渗的土柱实验,以分析不同SAR的咸水结冰融水入渗后,苏打碱土的水盐分布情况。结果表明:咸水结冰融化初期,矿化度和SAR均很高,后逐渐降低;与淡水结冰处理相比,咸水结冰融水处理在入渗土壤过程中,入渗速度快、深度深,并且SAR越小的咸水结冰处理,入渗速度越快、深度也越深,且差异极显著(P<0.01);这也使得表层(0-10 cm)土壤含水量SAR越小的咸水结冰处理含水量越低,而下层(深于10 cm)则越高,上层脱盐层含盐量越低,下层积盐层含盐量越高;与咸水直接入渗相比,咸水结冰处理的脱盐深度(含盐量<1.23%)为20-25 cm,浅于咸水直接入渗处理的25-30 cm,而在15 cm以上的土层平均含盐量显著小于咸水直接入渗处理,对于表层土壤的脱盐效果,咸水结冰处理要好于咸水直接入渗处理。

A soil column experiment was carried out to investigate the water and salt distribution of soda alkaline soil with infiltration of melting frozen saltwater in laboratory.The saltwater of one salinity levels（10 g/L）,three levels of SAR（5,10 and 30） and one water volume（678.2 ml） were used,and the CK was the frozen freshwater treatment.The results indicated that at the beginning of saline ice water melting,both the salinity and SAR of melted saline water were very high,and then declined extremely,fresh water was melted in the end.At the same melting time,the saline ice water treatments of high level of SAR gained a high value of SAR.In the course of infiltrating to soil,the infiltrating speed and depth of frozen saltwater treatments were faster and deeper than freshwater treatment significantly.the soil water content of 0-10 cm surface layer soil of frozen saltwater treatments were lower than freshwater,while it was higher in the layer of under 10 cm soil of frozen saltwater treatments.The depth of soil desalinization was deeper in frozen saltwater treatments than in freshwater.In the lower level of SAR frozen saltwater treatment,the water infiltrating speed and depth were faster and deeper.The difference of infiltrating characteristic among the treatments,led to the differences of water and salt transportation in soda alkaline soil.The soil water content of 0-10 cm surface soil layer was higher in lower SAR level frozen saltwater treatments than that in higher one,while it revealed reverse results in the 10-40 cm layer of soil.And in the salt leaching layer of soil,the soil salt content was lower in low SAR frozen saltwater treatments than that in high SAR levels,while it was reversed in layer of salt accumulation.The same salt water（S=10 g/L,SAR=10 and V=678.2 ml） was used to compare the effect of soda alkaline soil desalinization with infiltration of melting saline ice water and saltwater.The soil salt leaching depth of the treatment infiltrated with saltwater was 25-30 cm,deeper than 20-25 cm of the melting ice water infiltration treatment.While the average salt content of 0-15 cm layer soil was 0.47% in melting ice water infiltration treatment,lower than the 0.59% of saltwater infiltration in the same layer of soil.As to the surface layer of soil,the effect of soda alkaline soil desalinization was better with infiltration of melting saline ice water than that with salt water in above water quality.