退耕还林还草地区土壤有效水含量及蓄水性能研究--以陕西省吴旗县柴沟流域为例

对陕两省吴旗县黄土丘陵沟壑区退耕还林工程区的乔术（山杏和刺槐）、灌木（荆条、沙棘）及对照农田的土壤水分有效性和蓄水能力进行了比较研究。结果表明，不同植被类型的土壤有效水含量为1．92％～15．73％，林地比农田增加约75．3l％；0～40cm土层土壤蓄水量为228．30～251．07t／hm^2，林地比农田增加约8％；刺槐林地的蓄水性能好于山杏林地。结果对于科学地评价退耕还林工程的土壤改良效益、水源涵养效益具有重要的意义。

Study on Soil Water Availability and Water Storage Capacity in the Area of Upland Conversion Program--Case Study in Chaigou Watershed of Wuqi County, ShaanXi Province

Soil water availability and water storage capacity were comparatively studied under such vegeta- tion types as arbor (Prunus sibirica and Robinia pseudoacacia) and shrub (Vitex negundo var.heterophylla (Franch.) Reh and Hippohae rhamnoides L,with the farmland as the control.It was found that the soil water availability of different vegetations ranges from 1.92 percent to 15.73 percent,with 75.31 percent over farmland in the soil water availability for woodland.The total soil water storage within 40 cm depth ranges from 228.30 t/hm~2 to 251.07 t/hm~2,with the woodland about 8 percent over farmland in this re- gard.The soil water capacity of the woodland of Robinia pseudoacacia is larger than that of Prunus sibiri- ca.The findings are of importance to the effectiveness assessment of soil improvement and water conserva- tion in the regions of upland conversion program.