关键词: 放牧强度, 草甸草原, 全氮, 全磷, 全钾

Abstract: The influence of grazing intensity including light grazing (0.38 cattle·hm^-2), moderate grazing (0.64 cattle·hm^-2) and heavy grazing (0.90 cattle·hm^-2) on soil total nitrogen, total phosphorus, total potassium and pH in Zhaosu Meadow Steppe was studied from 2010 to 2012 by plot grazing experiment. Result showed that the contents of soil total nitrogen, phosphorus and potassium in 0~10 cm, 10~20 cm, 20~30 cm soil layers were not significantly different among different grazing intensities at the same year during the short grazing period, and the same as soil pH. Compared with before grazing, the soil total nitrogen content and soil pH of 0~30 cm soil layer after grazing decreased 5.8%~29.7%, 0%~5.0%, respectively; and the contents of soil total phosphorus and potassium increased 4.5%~29.2%, 35.0%~100.8%, respectively. The contents of soil total nitrogen, total phosphorus, total potassium increased and soil pH first increased then decreased with increasing grazing intensity. There was no significant correlation between grazing intensities and soil total nitrogen, total phosphorus, total potassium, pH under short grazing period. Whether grazing or not, the contents of soil total nitrogen and total phosphorus decreased, pH increased with the increase of soil depth. In short, different grazing intensities under short grazing period did not have significant influence on soil total nitrogen, total phosphorus, total potassium contents and soil pH value.

Key words: Grazing intensity, Meadow Steppe, Total nitrogen, Total phosphorus, Total potassium