多元统计分析在退耕还林区土壤溶液肥力评价中的运用

[目的]评价各退耕还林模式的土壤肥力等级。[方法]以四川洪雅退耕还林区4种退耕还林模式和农耕地5个土壤溶液肥力因子为例,采用多元统计的主成分分析法对土壤溶液肥力等级进行综合评价。[结果]用SPSS统计软件得出土壤溶液肥力因子前2个主成分的累计贡献率为78.583%。4种退耕还林模式和农耕地土壤溶液养分的排序为:模式Ⅲ下层>农耕地下层>农耕地上层>模式Ⅱ下层>模式Ⅳ下层>模式Ⅰ下层>模式Ⅳ上层>模式Ⅲ上层>模式Ⅱ上层>模式Ⅰ上层。就各模式土壤上层比较,模式Ⅳ(杂交竹+牛鞭草)上层在综合得分中排名第一。就各模式土壤下层比较,模式Ⅲ(牛鞭草)下层在综合得分中排名第一。[结论]该研究为制定合理的退耕还林模式提供了一定的科学依据。

Application of Multivariate Statistical Analysis in the Fertility Evaluation of Soil Solution in the Area of Returning Land from Farming to Forestry in Sichuan

[Objective] The purpose was to evaluate the soil fertility grade of various modes of returning land from farming to forestry.[Method] With 4 modes of returning land from farming to forestry in the area of returning land from farming to forestry and 5 factors of soil solution fertility in farming land in Hongya county of Sichuan province as examples,the synthesized evaluation was conducted on the grade of soil solution fertility by principal component analysis with multivariate statistics.[Result] The accumulative contribution rate of the first 2 principle components of factors in soil solution fertility was obtained by SPSS statistical software,being 78.583%.The order of soil solution nutrients in 4 modes of returning land from farming to forestry and farming land was: lower layer of mode 3 > lower layer of farming land > upper layer of farming land > lower layer of mode 2 > lower layer of mode 4 > lower layer of mode 1 > upper layer of mode 4 > upper layer of mode 3 > upper layer of mode 2 > upper layer of mode 1.Compared upper layers in soil of different modes,the upper layer of mode 4(hybrid bamboo limpograss) take the 1st position in comprehensive score.Compared lower layers in soil of different modes,the lower layer of mode 3(limpograss) take the 1st position in comprehensive score.[Conclusion] The research provided some scientific basis for setting down reasonable mode of returning land from farming to forestry.