Application of principal component analysis in evaluation of soil quality under different long-term fertilization
主成分分析方法在长期施肥土壤质量评价中的应用

Based on the experimental platform of Long-term Fertilization Test in the State Experimental Station for Agro-ecology in Fengqiu, Chinese Academy of Sciences, in this research the comprehensive soil quality was evaluated by the indicators of soil microbial activity and soil chemistry properties through principal component analysis. The results indicated that soil properties significantly differed with incomplete patterns among fertilization regimes. Soil quality could be revealed by two principal components through 15 soil properties which consisted of 10 soil properties with high factorial loads in the first component (PC1) including soil organic C, total N, alkali-hydrolyzable N, pH, microbial biomass C, microbial biomass N and activities of urease, invertase, FDA and dehydrogenase, and the rest with high factorial loads in the second one (PC2) including soil total P, total K, available N and P. The variation of soil quality was higher in PC1 than in PC2. Judging from the integrated scores of the both principal components, the highest soil quality displayed in OM, then followed the sequence of 1/2OM, NPK, NP, PK, NK and CK.