宁夏扬黄灌溉对土壤环境的影响

Impacts of Irrigation on Soil Environment by Lifting up Water from the Yellow River in Ningxia

本文在对宁夏扬黄灌区的同心县河草沟村的调查取样基础上 ,通过对灌溉地土壤灌溉前后以及灌溉地土壤与非灌溉地土壤之间的比较 ,分析了扬黄灌溉后 ,灌区土壤在盐分含量、土壤颗粒组成、土壤养分和土壤微量元素含量等方面的变化 ,以及这些变化对土壤沙化、土壤盐渍化和土壤环境质量等的影响。结果表明 ,扬黄灌溉在一定程度上抑制了土壤沙化 ,改善了表层土壤的盐分状况 ,提高了土壤肥力 ,但并没有彻底消除土壤盐渍化的潜在危害 ,也部分造成了土壤环境质量的下降。

In this study, soil survey was conducted at Hecaogou village of Tongxin County, which is located at the area of Ningxia irrigated by lifting up water from the Yellow River. On the basis of soil survey, irrigation induced changes in soil salinity, soil texture, nutrient and trace element content and their impacts on soil sandification, salinization and soil environmental quality were analyzed and discussed. The results indicate that: (1) Irrigation can obviously reduce the salt content of surface soil, but there is a trend for salt to gather at the depth of 50~90 cm and soil salization is likely to emerge again if irrigation were ceased or irrigation water were reduced; (2) The sandification is mitigated, with a decreasing in sand fraction and an increasing in clay fraction; (3) Irrigation may slightly increase the nutrient content, with the organic matter content and the total P increased more than others, while increase of Copper, Chromium, Zinc, Nickel and Cadmium content will partly decrease the soil environment quality and the soil F leaching is a challenge for reducing F poisoning in this area.