黄土高原刺槐林对土壤养分时空分布的影响

以不同树龄刺槐纯林林地和撂荒地作对比,研究了黄土高原刺槐人工林对土壤养分时空分布特征的影响。结果表明,刺槐林地土壤有机质、pH值、全氮、有效氮、有效磷、速效钾、交换性钙和交换性盐基总量随刺槐树龄增加无明确变化规律,土壤全磷和交换性镁含量则呈现波动性变化;刺槐林地土壤有机质、全氮、有效氮含量随土壤深度增加按幂函数衰减,有效磷含量有递减趋势,土壤全磷、速效钾、交换性钙、交换性镁和交换性盐基总量随土壤深度增加无明显变化规律,而土壤pH随深度呈波动性变化;与撂荒地相比,刺槐林地土壤有机质、全氮、有效氮、有效磷、速效钾、交换性钙、交换性镁含量及交换性盐基总量分别增加21.6%~96.8%,34.3%~160.1%,191.5%~238.4%,2.1%~24.1%,19.82%~92.71%,64.2%~80.0%,25.0%~46.5%和67.2%~89.5%,表明刺槐林对改善土壤养分状况具有重要作用。

Time-space Distributive Feature of Soil Nutrient and Chemical Characteristics of Robinia Pseudoacia L.Plantation Forestland in Loess Plateau

Time-space effect of soil nutrient and chemical characteristics of Robinia pseudoacia L.plantation forestland in Loess Plateau has been studied.The results shows that: soil organic matter,pH,total N,available N,available P and available K,exchangeable Ca and exchangeable base capacity changes irregularly with tree age,total P and exchangeable Mg changes fluctuantly;Soil organic matter,total N,available N decreases by power function with soil depth,available P tends to decreases,total P,available K,exchangeable Ca,exchangeable Mg and exchangeable base capacity varies irregularly with soil depth,but pH-value changes fluctuantly;Compared with wasteland,soil organic matter,total N,available N,total P,available P,exchangeable Ca,exchangeable Mg and exchangeable base capacity raises respectively by 21.56%~96.8%,34.3%~160.1%,191.5%~238.4%,2.1%~24.1%,19.82%~92.71%,64.21%~80.02%,25%~46.5%,67.2%~89.5%.These showed that Robinia pseudoacia L.plantation can improve the condition of soil nutrient effectively.