Abstract:

In order to identify the response of soil nitrogen to different grazing systems in Stipa breviflora desert steppe, continuous grazing (CG), banning grazing (BG), deferred grazing for 40 days (DG1), deferred grazing for 50 days (DG2), deferred grazing for 60 days (DG3) were chosen as different treatments, and the distribution of soil total nitrogen and available nitrogen content in different treatments and vertical distribution in each treatment were analyzed. The results were as follows: the soil total nitrogen content was lowest in CG treatment, the layers of content mean 0.76 g/kg. While available nitrogen content was higher in 0-10 cm and 10-20 cm soil layer compared with the other treatments, its contents were 87.41 mg/kg and 131 mg/kg. The available nitrogen in BG area was lower in 20-30 cm and 30-40 cm soil layer, the content 56.82 mg/kg and 51.59 mg/kg. As the vertical distribution, the soil total nitrogen was higher in 0-10 cm and 30-40 cm soil layers, average content were 1.33 g/kg and 1.09 g/kg. The available nitrogen was higher in 10-20 cm layer, each treatment area average 91.86 mg/kg. Deferred grazing was more prone to keep grassland soil nitrogen stable compared to continuous grazing.