水质和体积质量对碱土饱和导水率和盐分淋洗的影响

以松嫩平原典型碱土为研宄对象,采用承压水、潜水及蒸馏水模拟的雨水3种水源,分别在6种体积质量(容重)下测定了土壤饱和导水率和淋洗液的电导率及pH,分析了水质和体积质量对碱土饱和导水率和盐分淋洗的影响以及饱和导水率与淋洗液电导率和pH值间的关系.结果表明:碱土饱和导水率随测定用水电导率的增加而升高;采用承压水和潜水测定时,碱土饱和导水率随土壤体积质量的增加而降低;采用蒸馏水测定时,饱和导水率在1.08～1.33 g/cm~3体积质量范围内均为0.11mm/d,而当体积质量>1.42g/cm~3时,饱和导水率均为0 mm/d;淋洗液的电导率和pH值随着测定用水电导率的逐渐增加而不断降低;采用潜水和承压水测定时,淋洗液的电导率和pH值随体积质量的增加而升高,用蒸馏水测定时,淋洗液的电导率和pH值不随体积质量的变化而改变;淋洗液电导率和pH均随饱和导水率增加而降低,且二者与饱和导水率均呈指数关系,碱土饱和导水率越高其盐分淋洗效果越好.

Effects of water quality and bulk density on saturated hydraulic conductivity and salt leaching of sodic soil

This paper was to study the effect of water quality and hulk density on saturated hydraulic conductivity (K_(s10)) and on salt leaching, and study the relationship between K_(s10) and ieachate EC, K_(s10) and leachate pH. Results showed: K_(s10) increased with the increment of irrigation water quality; K_(s10) decreased with the increase of bulk density of sodic soil when shallow and deep ground water were used; while when distilled water was used, K_(s10) value was 0.11 mm/d and 0 mm/d with hulk density of sodic soil ranging from 1.08 g/cm~3 to 1.33 g/cm~3 and from 1.42 g/cm~3 to 1.50 g/cm~3, respectively; the values of EC and pH of leachate decreased with the increase of irrigation water quality; when shallow and deep ground water were used, the values of EC and pH of leachate increased with the increment of hulk density of sodic soil; while the values of EC and pH of leachate didn't vary with the increment of bulk density of sodic soil; the values of EC and pH decreased with the increase of K_(s10), the relationships between EC and K_(s10), pH and K_(s10) follow the exponential function.