Physical and Chemical Properties of Pinus yunnanensis Forest Soil in Jianshan, Yiliang, Kunming

In order to understand soil physical and chemical properties of Pinus yunnanensis forest, the 28 soil samples which were from 7 sampling plots (each sample included 2 sampling points, and each point sampled 2 soil samples from the soil layers of 0~20 and 20~40 cm) sampled to determinate parameters of soil physical and chemical properties located Jianshan, Yiliang County, Kunming in the mid of February of the dry season. The results showed that soil physical and chemical parameters of the 0~20 and 20~40 cm layers were as following:(1) The soil water content and bulk density were 8.2%~10.2%, 1.19~1.46 g/cm3 and 8.9%~13.6%, 1.45~1.68 g/cm3; (2)The pH value and organic matter were 4.0~4.5, 28.0~44.6 g/kg and 4.1~4.9, 5.9~19.6 g/kg; (3) The total N, P, K ranged as 1.0~1.8, 0.15~0.39, 5.0~23.7 and 0.3~1.1, 0.15~0.36, 5.2~24.8 g/kg, (4) Available N, P and K were only 80.0~1.25, 0.57~3.18, 67.5~130.5 and 23.0~69.0, 0.00~0.54, 67.0~128.5 mg/kg, respectively. The soil physical and chemical properties presented diverse variation with the changes of soil sampling niches and soil layers. Available N, P and K had significantly positive correlation to organic matter content (P0.05 or 0.01).It oriented that the dry, acidic, clay, insufficient phosphorus and low nitrogen were the soil properties of P. yunnanensis forest in Jianshan; the dry and insufficient P may constitute important causes of appearing grass stage and growing slowly during the seedlings and sampling stages which originated natural regeneration of P. yunnanensis.