宁夏低矿化度回归水灌溉对土壤盐碱化的影响

Effect of Irrigation with Low Degree of Mineralization Return Water on Soil Salinization in Ningxia, China.

通过利用低矿化度回归水的土柱模拟实验研究表明，在排水较好条件下，含盐１．３—１．６ｇ／Ｌ的低矿化度回归水灌溉可使中轻度盐渍化土壤脱盐。但随灌溉年限延长含盐量逐年增高，含盐量、ＳＳＰ、ＳＡＲ、Ｃｌ－的量与回归水中该值呈显著正相关。说明即使淡水也是土壤盐碱化的来源。采用混灌轮灌和良好的土壤改良管理措施，回归水可开发利用。

Under the good drainage condition, when degree of mineralization in the return water was less than soil salineness, irrigation with the return water can make soil desalinited evidently. Soil salineness increased gradually along with irrigation by the return water. SSP was more than 60%, K Mg was more than 50%,and SAR was more than 5 in the return water. Salineness, SSP, SAR and CDR in the soil have noticeable positive correlation to which in the return water. This fact indicated that even fresh water was also salt sources in the soil. Adopting appropriate irrigation system and soil management practices,the return water with low degree of mineralization can be reused.