湖北省几种主要旱地土壤水分特性的研究

SOIL WATER CHARACTERISTICS OF SEVERAL MAIN DRYLAND SOILS IN HUBEI

研究了湖北省黄棕壤等10种主要旱地土壤的水分物理性质。结果表明:这10种土壤的脱水曲线适于用指数式、幂函数式和直线式三种模型表达。土壤的持水能力以红壤较强,而以质地偏砂的潮土和紫色土较弱。10种土壤的各种有效含水量,以质地偏砂的潮土最高,质地粘重的红壤最低。这些土壤的水分性质与土壤的质地、总表面积及阳离子交换量等有密切关系。

Soil water characteristics of 10 kinds of dryland soils (Yellow cinnbmon soil,Calcareous concretion block soil, Purple soil, Limestone soil, Red soil, Yellow brownearth and 4 kinds of Alluvial soils) in Hubei have been studied. The empiricalequations for soil water characteristic curves may be modeled as s=aθ~b; s=ae^(bθ),s=a+bθ, where the s is the soil suction (bar), θ is the soil water content (g/100gdry soil), a and b are empirical parameters, b is negative. In the range of higher soil suction, the walerholding capacity of red soil is thelargest,and that of alluvial soil l of loamy sand is the smallest. In the range of lowersoil suction, the water-holding capacity of alluvial soils 3 and 4 whose texture aresilt loam is the largest, and that of purple soil is the smallest. Alluvial soils l and2 have the largest values for the total capacity of available water capacity (0.33-15bars), available water for normal growth of plant (0.33-1 bars)and rapidly availablewater capacity (0.33-6 bars), whereas red soil is samllest in all those 3 paramelers.The unavailable water capacity of red soil is the largest and that of alluvial soil 1and 2 is the smallest. The water characteristics of these soils are highly correlated with soil texture, soiltotal surface and CEC.