盐分对土壤水分特征曲线的影响

Effects of Salinity on Soil Water Characteristic Curve

为研究盐分对土壤水分特征曲线的影响,采用离心法测定不同5种含盐量下(0.1%、0.3%、0.5%、0.7%、1%)含NaCl、KCl、CaCl2、MgCl2、MgSO4土壤的土壤水分特征曲线,并设空白对照。结果表明,盐分使土壤水分特征曲线向右偏移,土壤持水性增大;随着含盐量的增加,土壤水分特征曲线偏移减少,持水性有所降低;而盐分种类对土壤水分特征曲线的影响无明显规律,各溶质间差异较小。VG模型参数θs、α、n与含盐量的相关性较高;修正VG模型能够较好预测含盐土壤的水分特征曲线。

To study the effects of salinity on soil water characteristic curve, centrifugation method was used to measure soil water characteristic curves of salty soils, such as NaCl, KCl, CaCl2, MgCl2, MgSO4 , whose soil salt contents were all 0%,0.1%, 0.3%, 0.5%, 0.3% and 1%, respectively. Results showed that salinity could make soil water characteristic curve shift to the right and improve soil water holding capacity. With the increase of soil salinity, the shifting of soil water characteristic curve and the water holding capacity decreased. The effects of salt types on soil water characteristic curve were not obvious, the differences between the solutes were smalh There were high correlations between the parameters of VG model and soil salt content. The modified VG model could well predict soil water characteristic curve of salty soil.