一二代马尾松林土壤养分特点及其对幼苗生长的影响

Nutrient Characteristics of Soil from the First and Second Generation of Pinus massoniana Forests and the Effects on Seedling Growth

利用一二代马尾松林下土壤,在相同环境条件下进行马尾松育苗试验,研究一二代马尾松林下土壤中主要养分含量及其对幼苗生长的影响。结果表明:连栽后土壤pH值有所降低,广西幼龄林、中龄林土壤有机质、全氮、全磷和全钾含量一代高于二代,而贵州一代中龄林土壤有机质、全氮、全磷含量一代低于二代,全钾含量则与广西土壤表现一致;3组样地土壤水解性氮、有效磷、速效钾含量均表现为一代低于二代;3组样地中,除广西幼龄林土壤水解性氮含量一二代之间差异显著外,其余样地土壤水解性氮含量差异均达到极显著水平。马尾松林土壤栽种的幼苗苗高、地上与根系生物量的积累、根系形态、根系活力均表现为一代略优于二代,一二代土壤养分含量能够满足马尾松幼苗的生长需要,不会对幼苗生长造成不利影响。

Using the soil from the first and second generation of P.massoniana forests,the potting experiment was carried out to research the effects of soil nutrients on seedling growth of P.massoniana in the same environmental conditions.The results showed that the pH decreased after continuous planting,while the content of organic matter,total N,total P,total K in the soil from young growth and half-mature forest of Guangxi and total K in the soil from half-mature forest of Guizhou of the first generation were higher than that of the second generation,but the organic matter,total N,total P contents from Guizhou were opposite.Hydrolysable N,available P and available K contents from the three couples of sample plot of the first generation were less than that of the second generation.The soil nutrients all above had extremely significant difference between the first and second generation and significant difference in hydrolysable N was found in soil from young growth of Guangxi.The seedling height,the biomass of above-ground and root,the root morphology and root activity of the first generation were higher than that of the second,respectively.In conclusion,the soil nutrients from the successive planting of P.massoniana forests could meet the demands of seedling growth and had no adversely impact on seedling growth.