晋西黄土区典型植被类型的土壤水分特征

在晋西黄土区,研究了荒草地、锦鸡儿灌木林地和刺槐乔木林地3种典型植被不同土层的土壤密度、含水量、贮水能力和入渗性能的差异及其相关性,结果显示:3种植被类型都能有效减小表层(0 20 cm)土壤密度;3种植被类型表层(0 20 cm)的土壤滞留贮水量较大,锦鸡儿林地(198.80 t·m-3)刺槐林地(166.10 t·m-3)荒草地(87.37 t·m-3),20 40 cm土层的土壤滞留贮水量也是锦鸡儿林地(127.30 t·m-3)刺槐林地(55.60 t·m-3)荒草地(47.30 t·m-3),表明在3种植被类型中,锦鸡儿林地对晋西黄土丘陵区土壤水分的涵养作用最强;锦鸡儿林地的土壤稳渗速率最大,为1.80 mm·min-1,刺槐林地次之,为1.46 mm·min-1,荒草地依然最小,且锦鸡儿林地土壤的均渗速率最大,为4.81 mm·min-1,其次是刺槐林地,为4.51 mm·min-1,荒草地最小。土壤密度与滞留贮水量呈极显著负相关关系,与土壤初渗速率和均渗速率呈极显著负相关关系,与稳渗速率呈显著负相关关系,非毛管孔隙度与稳渗速率和均渗速率存在极显著相关关系。Kostiakov模型和Horton模型对晋西黄土区3种植被类型土壤入渗过程模拟的拟合系数高达0.97和0.95,明显优于Philip模型(0.43)。

Comparative Analysis of Soil Moisture Characteristics Under Typical Vegetation Types in Loess Area of West Shanxi

The soil bulk density, the soil moisture content, the water storage capacity and the infiltration of grassland, Caragana sinica land and Robinia pseudoacacia land on the loess hilly region in west Shanxi Province were analyzed to compare the differences and correlations. The result showed that all the three vegetation types were able to effectively reduce the soil density of the surface layer. In terms of storage capacity, the retention storage capacity of 0-20 cm layer of the three vegetation types were higher, which performed that the C. sinica land (198.80 t·m^-3)>R. pseudoacacia land (166.10 t·m^-3)>grassland (87.37 t·m^-3), and the retention storage capacity of 20-40 cm layer were C. sinica land (127.30 t·m^-3)>R. pseudoacacia land (55.60 t·m^-3)>grassland (47.30 t·m^-3). It showed that the role of water conservation of C. sinica land on loess hilly area was the highest; in terms of soil infiltration, the steady infiltration rate of C. sinica land was the highest, which was 1.80 mm·min^-1, followed by R. pseudoacacia land, which was 1.46 mm·min^-1, grassland was the lowest; And the average infiltration rate of C. sinica land was also the highest, which was 4.81mm·min^-1, and followed by R. pseudoacacia land, which was 4.51 mm·min^-1, and the grassland was the lowest. It indicated that C. sinica land was the optimal choice in loess hilly area; the soil density was extreme significantly and negatively correlated with the retention storage capacity, initial infiltration rate, steady infiltration rate, and average infiltration rate, and was extreme significantly and positively correlated with the non-capillary porosity and both the steady infiltration rate and average infiltration rate. The smaller the soil density, the greater the non-capillary porosity, and the stronger the water conservation capacity of soil.