Effects of Nitrogen Application on Plant Growth and Soil Inorganic Nitrogen Content in Alpine Grasslands

摘要

In order to further determine the nitrogen demand of plants in alpine grassland ecosystem,different nitrogen levels(0,1,2,4,8,16,24,32 g/m^2)were designed through field control to study the responses of different plant functional groups(grass,sedge and weed)to different nitrogen application levels in the aboveground biomass and soil inorganic nitrogen(nitrate nitrogen and ammonium nitrogen).The results showed that with the increase of nitrogen application rate,the aboveground biomass of different functional groups increased linearly,and the soil inorganic nitrogen content increased with the increase of nitrogen application rate,among which treatments N16,N24 and N32 increased significantly in soil nitrate nitrogen content(P<0.05).The results showed that the optimal nitrogen content in alpine grasslands was 8 g/m^2,which could not only promote plant growth,but also effectively control soil nitrate nitrogen content.