放牧对黄土高原丘陵沟壑区林草地土壤理化性状的影响

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。草地和柠条林地土壤的有机C、全N和全P含量都随放牧强度的增加而减少,而速效K含量则都表现为中度放牧>重度放牧>轻度放牧;从畜牧羊种来看,绵羊相对于山羊来说对放牧地践踏较轻,其放牧地土壤容重较小,土壤含水量、有机C、全N、全P和速效K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 species of livestock on physical and chemical properties of surface(0~10 cm) soil of grazing grassland and Caragana korshinkii forest floor were studied at hilly and gully regions on the Loess Plateau-Pianguan,Shanxi Province.The results showed that grazing intensity directly influenced the soil physical structure of grazing grassland and C.korshinkii forest floor.The soil bulk density increased along with the increase of grazing intensity,while water content was decreased.The contents of organic matter,gross nitrogen and gross phosphorus in the soil of grazing grassland and grazing C.korshinkii forest floor all decreased with the increase of grazing intensity,while the contents of quick available potassium in the soil of grazing grassland and grazing C.korshinkii forest floor were medium grazed paddocks > heavy grazed paddocks > light grazed paddocks.Compared with goat selected as grazing livestock,sheep had less effect on trampling soil with smaller soil bulk density,and also water content and the contents of soil organic matter,gross nitrogen,gross phosphorus and quick available potassium of the grazing land under sheep were higher than those under goats.