镜泊湖全新世玄武岩台地土壤养分特征分析

Analysis of Soil Nutrient Characteristics of Holocene Basalt Mesa in Jingbo Lake

采用野外调查和室内分析的方法,测定镜泊湖全新世玄武岩台地土壤化学养分的含量。对土壤养分成分进行主成分分析和聚类分析。先将7个养分指标简化成两个主成分,主成分I代表土壤综合养分水平,主成分II主要反映土壤的速效K和速效P水平,再利用主成分得分进行聚类分析,将11个样地分为4类,探讨每类样地土壤养分的特征及差异产生的机理。结果表明:玄武岩台地上的土壤养分整体水平较高,其中土壤有机质、全N、碱解N和速效K的含量丰富,全P和速效P含量较少;不同的人为干扰方式显著影响研究区土壤养分变化的程度和方向,种植农作物后土壤各项养分指标均大幅度下降,放牧增加了土壤的各项养分指标;位于台地边缘裸露玄武岩缝隙中的薄层土壤,有明显养分富集现象。

A study was conducted to determine the contents of chemical nutrients in Holocene basalt mesa in Jingbo Lake by field investigation and indoor analysis. Principal component analysis and cluster analysis were used to analyze the soil nutrient components. Two main components were obtained from seven soil nutrient indices, and component I represented the synthetic level of soil nutrients and component II represented the level of soil K fertilizer and available P. Eleven sample plots were classified into four classes by cluster analysis in terms of principal component scores, and the soil nutrient characteris- tics and the mechanisms causing the difference in soil nutrients between different classes were discussed. Results show that the whole level of soil nutrients of Holocene basalt mesa in Jingbo Lake is relatively high, in which the contents of soil organic matter, total N, available N, and available K are higher, and the contents of total P and available P are lower. Various human disturbances have significant effects on soil nutrients in the research area. Soil nutrient indices obviously decreased after planting crops and increased after grazing. A distinct phenomenon associated with nutrient enrichment was observed in the thin soil in exposed basalt gap on the edge of the mesa.