Effects Of Nitrogen And Phosphorus Addition On Soil Organic Carbon In Sub-alpine Meadows Of The Qinghai-Tibetan Plateau

Recent years, nitrogen deposition showed a rapid increase owing to the increase of the artificial emissions to the atmospheric of reactive nitrogen compounds which caused by the burning of fossil fuels, the production and use of chemical nitrogen fertilizer as well as the rapid development of animal husbandry. Nitrogen deposition under artificial interference has become an important part of the global nitrogen-biochemistry cycle. A sharp increase in the number of nitrogen deposition will seriously affect the productivity and stability of terrestrial and aquatic ecosystems. Nitrogen deposition has influenced on soil fertility and soil microbial diversity.To study the effects of nitrogen and phosphorus addition on organic carbon in sub-alpine meadows of the Qinghai-Tibetan Plateau, we carried out a nitrogen and phosphorus addition experiment in the field. The experiment included10treatments:N5, N10, N15; P5, P10, P15; N5P5, N10P10, N15P15, and blank control. The results showed that:1. Low concentrations of N addition increased the soil nitrogen accumulation, high concentrations of P addition increased to the soil total phosphorus accumulation.2. Soil microbial biomass increased under low concentrations of N, P addition, but it decreased under high concentrations of N, P addition.3. N, P addition enhanced the soil organic carbon mineralization. However, only low concentrations of N, P addition enhanced the soil organic carbon mineralization significantly.4. Low concentrations of N, P addition increased soil organic carbon.