Study On Factors Affecting The Soil Productivity Of Taiyue Mountain Plantation

This study uses 8 types of forest(20-year-old Pinus tabuliformis Carr.,40-year-old Pinus tabuliformis Carr.,80-year-old Pinus tabuliformis Carr.,100-year-old Pinus tabuliformis Carr.,40-year-old Pinus tabuliformis Carr.thinning,clear cutting of Pinus tabaliformis Carr.forest after 40 years of growth,20-year-old Pinus tabaliformis Cdrr.Larix gmelinii(Rupr.)Kuzen.mixed forest and 20-year-old Larix gmelinii(Rupr.)Kuzen.forest were studied.The soil fertility status of different forest types was analyzed.The indicators included soil pH,maximum water holding capacity,total porosity,bulk density,capillary porosity,water content,and non-capillary tubes.Porosity,organic carbon,inorganic nitrogen,total nitrogen,total phosphorus,microbial biomass carbon,nitrogen,phosphorus,using soil fertility evaluation methods and ecological chemometrics analysis,aiming at the development of soil fertility maintenance measures for Taiyue Mountain plantation in Shanxi Scientific basis.The results are as follows:(1)The soil bulk density of Pinus Pinus tabuliformis Carr forest gradually decreased with the forest age,while the soil moisture content was opposite.The soil organic carbon,total nitrogen and microbial biomass showed an overall upward trend,showing a certain surface aggregation effect(2)The content of ammonium and total nitrogen in the three forest types was higher than that in the lower soil.The content of organic carbon and inorganic nitrogen in the lower layer of the mixed forest was the highest,and the microbial biomass was high in the topsoil.(3)Under human disturbance(clear cutting and thinning),soil total porosity,capillary porosity,and maximum field water holding capacity were higher than the control plots.The microbial biomass nitrogen and phosphorus were the highest,and the control oil pine forest was the lowest.(4)Soil fertility evaluation shows that soil bulk density,capillary porosity,non-capillary porosity and nitrate nitrogen have great influence on soil fertility and determine the soil fertility level.The top four soil composite indexes are:40 years old pinus Pinus tabuliformis Carr,40 years old pinus Pinus tabuliformis Carr,100 years old pinus Pinus tabuliformis Carr and 40 years old pinus Pinus tabuliformis Carr after clear-cutting.The soil fertility evaluation score of the 80-year-old oil-growing pine forest in the upper soil was the lowest.The 80-year-old oil-growing pine forest had a large accumulation and fine root biomass,indicating that it grew rapidly and consumed too much soil nutrients.Therefore,the soil fertility evaluation index was low.(5)According to the study of ecological stoichiometric characteristics,C:N and C:P are basically equivalent to the average level in China,and the supply of P element content is sufficient,but N:P is lower than the average level,indicating that the forest soil in this region is still restricted by nitrogen.