放牧对黄土高原丘陵沟壑区林草地土壤特性的影响

在黄土高原丘陵沟壑区——山西偏关县通过放牧试验研究了草地和柠条林地在不同放牧强度、不同放牧畜种条件下表层土(0~10 cm)的物理和化学性质。结果表明,放牧强度直接影响着草地和柠条林地土壤的物理结构。随放牧强度的增加,牲畜对土壤的践踏加剧,导致土壤紧实度增加,容重上升,含水量下降。草地和柠条林地的水解氮含量都随放牧强度的增加而增加,速效钾含量则都表现为中度放牧>重度放牧>轻度放牧;速效磷的含量草地随放牧强度的增加而减少,柠条林地的速效磷含量则随放牧强度的增加而增加。从畜牧羊种选择来看,绵羊相对于山羊来说对放牧地践踏较轻,土壤容重较小,土壤含水量、水解氮、速效磷和速效钾含量则较高。

Effects of Grazing on Soil Physical and Chemical Properties of Grassland and Forest Floor in Hilly and Gully Regions on the Loess Plateau

The effects of different grazing intensity and different types of livestock on physical and chemical characteristics of surface(0~10 cm) soil for grazing grassland and Caragana korshinkii korn were studied at hilly-gully regions on the loess plateau of pianguan, Shanxi province.The results showed that grazing intensity directly influenced the physical structure of soil for grazing grassland and Caragana korshinkii korn.The soil bulk density increased along with the increase of grazing intensity,while water content was decreased.The contents of hydrolyzable nitrogen in the soil for grazing grassland and grazing Caragana korshinkii korn increased with the increase of grazing intensity,while the contents of quick available potassium in the soil for grazing grassland and grazing Caragana korshinkii kom were medium grazed paddocks>heavy grazed paddocks>light grazed paddocks.The contents of quick available phosphorus in the soil for grazing grassl and decreased with the increase of grazing intensity, while the contents of quick available phosphorus in the soil of grazing Caragana korshinkii komincreased with the increase of grazing intensity.Compared with goat selected as grazing livestock, sheep had less light of effect on trampling and had less small soil bulk density, also water content, the contents of hydrolyzable nitrogen, quick available phosphorus and quick available potassium of the grazing land under sheep is higher than under goat.