土壤因子对杂交鹅掌楸幼林生长的影响

Soil factors influencing juvenile growth of Liriodendron chinense × tulipifera

以3个试验点杂交鹅掌楸Liriodendron chinense×tulipifera试验林为材料,研究了土壤容重、p H值以及全氮、碱解氮、全磷、有效磷、全钾、速效钾及有机质质量分数等9个土壤因子对杂交鹅掌楸幼林生长量（1~8年生）的影响。结果表明：土壤因子在不同地点、坡位与土层间均存在显著差异（P〈0.05）;杂交鹅掌楸幼龄期生长量在不同地点间以及地点内区组间存在显著差异（P〈0.05）。相关分析表明：除1~2 a地径与速效钾质量分数相关不显著外,其余各年份的杂交鹅掌楸树高与胸径均与土壤碱解氮质量分数和速效钾质量分数呈显著正相关（P〈0.05）,说明碱解氮和速效钾是影响杂交鹅掌楸生长的2个关键土壤因子,提高土壤碱解氮及速效钾质量分数可促进杂交鹅掌楸幼林期生长。这对于杂交鹅掌楸造林立地选择及幼林期土壤养分管理有指导意义。

To determine the impacts of soil factors on juvenile growth in years 1 through 8 for Liriodendron chinense x tulipifera, thirty 8 m×8 m plots from 3 plantations having dozens of interspecies crosses were sampled for 9 soil characteristics including soil bulk density, pH, total and hydrolyzed N, total and available P, total and available K, and organic matter. Growth （height and DBH） of trees within a plot were also measured followed an random complete block （RCB） design with 3-4 replications. A correlation analysis and a （duncan＇s multiple range test） were conducted. Results revealed differences of soil factors existing among the sites, slope positions, and soil layers in a site. Juvenile growth differed significantly among the sites （P〈0.05） and blocks in a site （P〈O.05）. No significant correlation existed between ground diameter and available K （r =0.287- 0.323, P = 0.081-0.124） during the first and second year; but height and DBH were significantly （P〈0.05） and positively correlated （r = 0.369-0.711） with soil hydrolyzed N and available K for years 3 through 8 showing that hydrolyzed N and available K were the two critical soil indexes for growth. Thus, enhancing hydrolyzed N and available K could promote juvenile growth of Liriodendron chinense x tulipifera and could provide guidance for tree selection and soil nutrition management in the juvenile stage of large scale afforestation projects. [Ch, 6 tab. 20 ref.]