Effects of Nitrogen Combined Application on the Vegetation and Soil of Degraded Alpine Meadow in the Three-River Headwaters Region [氮素配施对三江源区退化高寒草甸植被和土壤的影响]

作者：Chang T.; Zhang Q.; Qin R.-M.; Su H.-Y.; Wei J.-J.; Cheng H.-J.; Zhao T.-Y.; Shao X.-Q.; Zhou H.-K.^*

来源：草地学报, 2020, 28(4): 860-867.

DOI：10.11733/j.issn.1007-0435.2020.04.028

• Alpine meadow
• Biomass
• Nitrogen combined application
• Restoration effect
• Soil nutrients

The degradation of grassland in Thrcc-Rivcr Headwaters Region is a serious threat to our ecological security, so it is of great significance to study the effects of grassland restoration measures on grassland. In this study, a slightly degraded alpine meadow in Guoluo Tibetan Autonomous Prefecture of Qinghai Province was selected as the research sample. To explore the effect of different nitrogen combined application on the restoration of degraded alpine meadow,wc analyzed the community characteristics and soil nutrient changes of degraded alpine meadow after the applications of nine nitrogen combinations from three different types of nitrogen (urea CHi N2 O? ammonium sulfate (NH,i)2SO,i and potassium nitrate KNOs). The results showed that compared with the control, nitrogen combined application significantly increased community primary productivity (P<CO. 05), but had no significant effect on plant community diversity. The available nitrogen and nitrate nitrogen in the meadow soil showed a decreasing trend (P<0. 05), but the contents of organic carbon,total nitrogen?total phosphorus and ammonium nitrogen had no significant changes. Based on the principal component analysis,the optimal combining rate of nitrogen application rate for the restoration of alpine meadows was selected as 47. 2 g ? m -2 ammonium sulfate 十 72. 2 g ? m-2 potassium nitrate 十21. 6 g ? urea?which provided a theoretical basis for of the nitrogen application for the restoration of degraded alpine meadow.

• 单位
  中国科学院大学; 中国农业大学