Study On The Course Of Soil Nitrogen Mineralization And Influence Factors In Larix Gmelinii Forests

About 240 soil samples are collected to study the course of the soil nitrogen mineralization in Larix Gmelinii Forests in situ field experiments .It mainly researched as follows: the dynamic changes of soil nitrogen mineralization in different soil layers ,different forests and different incubate times. Also we study the soil physical and Chemical characters having influence on the nitrogen mineralization, the conclusions are follows:(1)In the study area the change of soil organic matter is from -6.43 to 35.4mg/kg,the change of total nitrogen is from 2.89 to 17.86g/kg, the change of the available P is from 6.99 to 165.1mg/kg,The change of the available K is from 159.65 to 736.25mg/kg , the PH is from 3.98 to 5.51,the change of soil bulk density is from 0.08 to 0.96 g/cm³. The variations of soil physical and chemical is very large.(2)In the study area the change of soil nitrification is from -6.43 to 35.4mg/kg, the change of soil ammonium is from -3.76 to 66.67 mg/kg, the change of soil nitrogen mineralization rate is from -0.16 to 3.40mg. kg^-1.d^-1, and the humus layer of nitrogen mineralization rates were greater than the illuvium layer. The maximum mineralization rates appear on the July 17th to August 16th in the chaihua forest.(3)From the physical and chemical factors, the impacts of nitrogen mineralization rates of humus layer are soil organic matter, total nitrogen and PH. The impacts of nitrogen mineralization rates of layer are main soil organic matter, total nitrogen, PH, C / N and available phosphorus. Judging from the meteorological factors, soil nitrogen mineralization rate and soil temperature and a positive correlation between temperature and soil moisture, which with precipitation increased showing first increasing then decreasing . Considering physical and chemical factors and meteorological factors, through the principal component analysis: the order on the impact of humus layer and illuvium layer of mineralization rate is C / N, temperature, available phosphorus, soil organic matter, total nitrogen, potassium, rainfall and soil temperature.