关键词: 土壤因子, 群落特征, 放牧强度, 高寒草甸

Abstract: A 12-year field micro-plot trial with meadow brown soil planted with corn was conducted in Shenyang to study corn yield, nutrient uptake and soil nutrient budget under the longterm impact of different P fertilization methods (application rate and frequency). The results showed that P was not the most important factor affecting the corn yield in this area. Fertilization increased nutrient uptake, with the treatment order of NP>N>CK, and P application once per six years was better than annual P application. Compared with the background values of soil, fertilization increased the concentrations of total P, OlsenP, total N and alkali hydrolyzable N in soil plough layer (0-20 cm) with the treatment order of NP>N>CK, while the concentrations of total K and available K declined with the treatment order of NP>N>CK due to long-term lack of K application. Soil OlsenP concentration decreased in the treatment with no fertilization and increased in the treatment with only N fertilization, but they both did not change obviously. The soil OlsenP concentration was increased gradually under the annual P application treatment. In contrast, when under the once per six years P application treatment, the soil OlsenP concentration was the maximum in the first year after P application, and decreased thereafter, which implied that P application once per six years was better than annual P application for the establishment of soil “grand” available P pool. On the premise of adequate N application, the quantity of P application was equal to or slightly higher than that of corn uptake with a N/P ratio between 1:0.167 and 1:0.5 for the balance of soil nutrient budget.

Key words: community characteristics, soil factor., grazing intensity, alpine meadow