• 研究报告 •

氮磷添加对亚热带常绿阔叶林土壤氮素矿化的影响

1. （安徽农业大学林学与园林学院， 合肥 230036）
• 出版日期:2013-07-10 发布日期:2013-07-10

Effects of N and P addition on soil nitrogen mineralization in a subtropical evergreen broadleaved forest.

ZHAO Yang, ZHANG Chi, ZHAO Hong-fei, XU Xiao-niu**

1. (College of Forestry and Landscape Architecture, Anhui Agricultural University, Hefei 230036, China)
• Online:2013-07-10 Published:2013-07-10

Abstract: Three treatments (no nutrient addition, CK; N addition, 100 kg N·hm-2·a-1; and N+P addition, 100 kg N·hm-2·a-1 + 50 kg P·hm-2·a-1) were installed in an evergreen broadleaved forest in  northern subtropics to study the effects of nutrient addition on the soil nitrogen dynamics and mineralization in the forest. The annual mean inorganic N concentrations (NH4+-N + NO3--N) in 0-10 cm and 10-20 cm soil layers for the treatments CK, N addition, and N+P addition were 7.27 and 6.80 mg·kg-1, 13.94 and 8.92 mg·kg-1, and 11.20 and 7.13 mg·kg-1, respectively, among which, the percentages of NH4+-N to total inorganic N were 90.66% and 91.15%, 65.78% and 72.85%, and 84.64% and 85.08%, respectively. The net ammonification, nitrification, and N mineralization rates in the 0-10 cm and 10-20 cm soil layers of the three treatments showed the similar seasonal patterns, with the maximum in summer and the minimum in winter. There were no significant differences for the net rates of N transformation in spring and autumn. Nutrient addition (N and N+P) decreased the annual average net rates of nitrogen mineralization. N addition decreased the net nitrification rate but increased the net ammonification rate, whereas N+P addition increased the net nitrification rate but decreased the net ammonification rate. Due to the long-term dynamic processes of forest ecosystems in response to nutrient addition, it would be necessary to conduct a long-term observation on the nitrogen dynamics in forest ecosystems under scenario of increasing N deposition.