桂北地区土地利用类型对土壤饱和导水率和持水能力的影响研究

Influence of Land Use Types on Soil Saturated Hydraulic Conductivity and Water Retention in Northern Guangxi

土壤饱和导水率和田间持水量是土壤重要的物理性质,也是表征土壤入渗性能和土壤持水性能的重要参数之一。通过测定桂北地区不同土地利用类型的土壤饱和导水率和田间持水量,探究土地利用类型对土壤饱和导水率和持水能力的影响。结果表明:不同的土地利用类型下,土壤饱和导水率存在明显的差异性,饱和导水率从大到小依次为农田、天然林、人工林、人工草地、桉树林,饱和导水率的误差范围从大到小依次为:农田、人工林、人工草地、桉树林、天然林;不同的土地利用类型对土壤田间持水量的影响也不同,土壤的田间持水量从大到小依次为:天然林、桉树林、人工林、人工草地、农田,天然林的持水性能相对最好;相对于土壤有机质含量,土壤孔隙度对土壤饱和导水率的正向影响更大,而在一定范围内,土壤有机质含量增加有利于提高土壤持水性能。

Soil saturated hydraulic conductivity and soil field capacity can be used to characterize physical prop- erties of soil, and are also the vital parameters describing soil water infiltration and soil water retention. In this study, the soil saturated hydraulic conductivity and soil field capacity of various land use types in the northern Guangxi areas were measured to investigate the effects of different land use types on soil saturated hydraulic conductivity and soil water retention. The results showed that the variations in soil saturated hy- draulic conductivity over different land use types displayed significant differences. The soil saturated hydrau lic conductivity declines sequentially in farmland, natural forestland, artificial forestland, artificial grassland and eucalyptus forestland and the error range of the soil saturated hydraulic conductivity dropped in the order of farmland, artificial forestland, artificial grassland, eucalyptus forestland and natural forestland. Further- more, the soil field capacity is also different under the distinct conditions of the land use types. The soil field capacity in diversified land use types aligned with the set in natural forestland, eucalyptus forestland, artifi- cial forestland, artificial grassland and farmland, of which the soil water retention of the natural forestland is even pronounced. Compared with the soil organic matter content, the soil porosity presents the more positive influence on the soil saturated hydraulic conductivity. However, the soil organic content facilitates the soil water retention under the limited conditions.