洛惠渠灌区水土化学特性分析

为了深入了解洛惠渠灌区土壤盐碱化程度,分别测试了2004年实地采集的63个土壤样品和71个地下水样品,测定项目分别为土壤含盐量、碱化度、阴阳离子含量和地下水化学成分,并分析了该灌区土壤盐碱化现状以及地下水水质状况.结果表明,洛惠渠灌区土壤盐碱化较明显,盐渍化土壤分成盐土和碱土两类,主体成分为钠(钾)、钙的硫酸盐和碳酸盐;而地下水化学类型基本属于氯化钠-硫化钠型.通过计算其钠吸附比和镁系数可以推知该灌区地下水大部分对灌溉作物有不利影响,并且对土壤有进一步碱化的威胁.因此,有效控制该灌区地下水位是治理土壤盐碱化的重要措施,还要考虑不同区域土壤易溶盐含量,作物耐盐碱性等因素.应当综合工程、生物、化学等方法来改良利用盐碱土地,方能起到事半功倍的治理效果.

Water and Soil Chemical Characteristics in the Luohui Trench Irrigation District

In order to understand the extent of soil salinization in the Luohui Trench Irrigation District,63 soil samples and 71 groundwater samples were collected in situ in 2004.Soil salt content,degree of alkalization,anion and cation content,and chemical composition of groundwater were measured respectively.The present situation of soil salinization and the status of groundwater quality were analyzed.Results show that soil salinization in the irrigation district is considerably serious.Saline soils may be classified as the two categories of saline soil and alkali soil.The main salinity composition is consisted of sulfate of sodium(potassium),calcium,and carbonate.The chemical characteristic of groundwater is in the category of sodium chloride-sodium sulfide,basically.It can be inferred that most of groundwater in the irrigation district has an adverse effect on irrigated crops according to its sodium adsorption ratio and magnesium coefficient calculated and has a threat of further alkalization to soil.Hence,an effective control of soil salinization is an important measure to control groundwater table in the irrigation district.Such factors as the concentrations of soluble salts of different districts and the salt-alkali tolerance of crops should be taken into account as well.It is suggested that the measures of engineering,biology,and chemistry should be combined to get twice the achievement with half the effort.