Effects Of Grazing Intensity And Grazing System On Soil Physical Properties And Soil Nutrients Of Alpine Meadow On The Northern Shore Of Qinghai Lake,china

Alpine meadow on the northern shore of Qinghai Lake is important grazing pasture land in China, which has a important role for the development of animal husbandry. Nevertheless, in recent years, human use of unreasonable grazing pastures occur severely degraded.How to realize resources sustainable in alpine meadow on the northern shore of Qinghai Lake and highest economic benefits has become the most concern problem. In this study, experimental animals is Tibetan sheep, set different grazing system and intensity to explore the grassland soil physical properties and soil nutrients of the dynamic changes, used to evaluate the impact of different grazing systems and intensitys on grassland health status. Provide a theoretical basis for the rational use of resources of alpine meadow on the northern shore of Qinghai Lake grassland plants, achieve the harmonization of economic and ecological benefits, and promote the sustainable development of animal husbandry.The main research results were as follows:1、The effects of grazing on soil moisture only occured at the end of growing season(September). Because the grazing time of winter pasture was at the non-growing season, the effects of grazing on soil moisture is unconspicuous. 2、 Annual pastures variation of surface soil compaction with grazing intensity increased. There was no change between the soil density of moderate grazing area(light, moderate) in autumn rotational grazing pasture and that in fencing area. 3、The effect of soil bulk density in annual pasture and autumn rotational grazing pasture was inconspicuous. 4、The content of soil organic matter in the moderate and heavy grazing area in annual pasture,moderate grazing area in summer pasture and all grazing area in winter pasture was decreasing with the increasing of soil depth. It is contrary in heavy grazing areas in summer pasture. The content of soil total nitrogen was increasing with the increasing of grazing intensity in annual pasture and summer pasture,it is contrary in winter pasture.The content of soil available phospfor were no significant trend in annual pasture and autumn rotational grazing pasture.