锡林郭勒草原不同植被类型的土壤水分特性

Soil Moisture Characteristics of Different Types of Vegetation in Xilingol Grassland

根据压力膜仪测得土壤水分特征曲线，分析了锡林郭勒草原4种植被类型下0-50cm土层的土壤水分特性。结果表明：在中、低吸力段（〈1.5MPa）土壤水吸力与土壤含水量之间存在显著相关关系，且各植被类型不同土层的曲线形状和变化趋势基本相同。4种植被类型下，土壤有效水含量、土壤持水能力和土壤供水能力呈现出多伦克氏针茅草原〉锡林浩特羊草草原〉东乌珠穆沁大针茅草原〉多伦农田。在多伦克氏针茅草原、锡林浩特羊草草原和多伦农田，随着土层深度的加深，土壤质地逐渐变粗，土壤有效水含量、土壤持水能力和土壤供水能力逐渐减小；在东乌珠穆沁大针茅草原，随着土层深度的加深，土壤机械组成先变粗后变细，在20-30m质地最粗，土壤有效水含量、土壤持水能力和土壤供水能力先减小后增大。

An experiment was conducted to study the soil water characteristics of four different types of vegetation in 0-50 cm soil layer according to soil-water characteristic curve measured by pressure membrane apparatus in Inner Mongolia. Results showed that there was a significant correlation between soil moisture content and soil suction under low and medium soil suction（ 〈 1.5 MPa）, and the shapes and changing tendencies of correlation curve for different vegetation types were basically the same. For the four vegetations types, soil available water content, soil water retention and soil water supply showed Duolun grassland 〉 Xilinhot grassland 〉 Dongwuzhumuqin grassland 〉 Duolun farmland. In Duolun grassland, Xilinhot grassland and Duolun farmland, soil particle size became bigger with the increase of soil depth, so soil available water content, soil water retention and soil water supply gradually decreased. While in Dongwuzhumuqin grassland, soil particle size first became bigger and then became smaller, with a largest soil particle size at the depth of 20-30 cm, so soil available water content, soil water retention and soil water supply first became smaller and then became bigger.