覆沙与漫灌对盐渍土盐分累积和运移规律的影响

Effects of sand covering and flood irrigation on salt accumulation and transport rule in saline soil

以陕西省榆林市定边县典型盐渍土为研究对象,采用覆沙和漫灌的方式,对0~30cm表层土壤的全盐量、电导率、pH值、水溶性离子含量等进行研究,探索其盐分累积和运移变化规律。结果表明:FS10、FS20和MG+FS10均可以显著降低表层土壤中的盐分含量,与对照相比,分别降低了73.9%、64.1%和56.5%,其中,覆沙10cm处理下的压盐效果最好。从土壤中水溶性阳离子组成来看,Na^+含量最高,其次是K^+,两者总和约占11.16%~34.33%;从土壤中水溶性阴离子组成来看,强碱性离子HCO_3^-含量最高,约占21.53%~53.86%。覆沙10cm处理下,Na^+、K^+、Cl^-和SO_4^(2-)的含量显著低于对照,表明覆沙可以显著抑制Na^+、K^+、Cl^-和SO_4^(2-)的表聚作用。漫灌也可以降低表层盐渍土中的全盐量,但是在地下水位较高的区域并不适用。

This paper takes the typical saline soil in Dingbian County,Yulin City,Shaanxi Province as the research object,and adopts the method of sand covering and flood irrigation to measure the total salt content,conductivity,pH value and water-soluble ion content of 030cm surface soil,studying the salt accumulation and transport rule.The results showed that FS10,FS20and MG+FS10could significantly reduce the salt content in topsoil,which was 73.9%,64.1%and 56.5%lower than that of the control,respectively.The effect of FS10was best.From the composition of water-soluble ions in soil,the Na+content was the highest,followed by K+,and the sum of the two accounting for 11.16%34.33%.From aspect of water-soluble ions composition in soil,the strong alkaline ion HCO3-content was the highest,accounting for21.53%53.86%.The content of Na+,K+,Cl-and SO42-was significantly lower than that of the control under the treatment of sand covering 10cm.This indicated that the sand covering could significantly inhibit the aggregation of Na+,K+,Cl-and SO42-.Flood irrigation could also reduce the total salt content in the surface saline soil,but it was not applicable in areas with high groundwater levels.