克拉玛依农业开发区土壤质量评价指标的筛选

根据主成分的相关结构分析理论 ,构建了一个对土壤主要质量指标进行筛选的数学模型。运用该模型对新疆克拉玛依农业开发区土壤质量主要指标进行了筛选 ,从 2 4项指标中筛选出 1 4项 ,并利用分层聚类的方法对筛选结果进行了检验。筛选前后的指标分别聚类 ,两次聚类过程相似 ,筛选后指标减少、特征根降低 ,相对增大了主成分对总方差的贡献率 ,使主成分结果更明显 ,并且可避免个别土样异常指标对聚类产生的影响。筛选后的聚类结果与室内按 1 996年土壤详查报告划分标准所作的分类更相近 ,说明所选指标基本上可反映开发区土壤的主要特性 ,筛选结果可信

Selection of the Main Evaluation Indexes of Soil Quality in the Karamay Agricultural Developing Area

The Karamay Agricultural Developing Area is characterized by the advanced farming technology, big investment and complete infrastructure. However, there are also some problems, such as the low soil fertility and secondary soil salinization. To monitor the change of soil quality in the developing area can provide the scientific bases for the synthetic agriculture development and the sustainable and rational utilization of land resources. There are many factors affecting the soil quality. In this paper, a mathematical model is developed for selecting the evaluation indexes of soil quality based on analyzing the theory of related structure of the main component. By using the developed model, 14 indexes are selected from the 24 indexes of the soil quality in the Karamay Agricultural Developing Area, and the selected indexes are tested by hierarchical cluster analysis. Although the two processes of cluster before and after the selection are similar, the indexes and the eigenvalues are reduced after selecting, the contribution of the main component to the total variance is greatly increased, and the result of the main component is made to be more obvious. Moreover, the influence of the abnormal indexes of very few soil samples to the cluster can be avoided, and the cluster results after selecting are closer to the classification standards of soil survey in 1996. These reveal that the selected indexes can basically reflect the main soil properties in the developing area, and the selected results are reliable.