土壤盐分对土壤水分扩散率的影响

土壤水分扩散率是土壤水盐运动的重要参数之一。利用水平土柱吸渗法对不同含盐量土壤的水分扩散率与含水量之间的关系进行了测定,并建立了土壤水分扩散率、土壤含水量与Boltzmann参数间的定量关系。结果表明,不同含盐量土壤之间的水分扩散率存在明显差异,表现在相同土壤含水量情况下,土壤水分扩散率随土壤含盐量的增大而增大;土壤水分扩散率随土壤含水量增大而单调增大,且当含水量接近饱和时,土壤水分扩散率接近无穷,通过建立含水量与土壤水分扩散率的经验函数关系能较好地反映了土壤含水率与土壤水分扩散率间的关系。

Influence of Soil Salt Content on Soil Water Diffusivity

Soil water diffusivity is a significant parameter for water and salt transport in saline soil.Horizontal soil column method is used to study the relationship between soil water diffusivity and soil water content in different saline soils.The relationships among soil water diffusivity,soil water content,and Boltzmann parameter are determined.Soils with different salt contents are found to have different soil water diffusivities.Soil water diffusivity increases with increased salt content under the same condition of soil water content.Soil water diffusivity increases with increasing soil water content as well.When soil tends to be saturated,soil water diffusivity approaches infinity.The empirical relationship presented in the paper may better reflect the relationship between unsaturated soil water diffusivity and soil water content.