基于主成分分析的豫中植烟土壤肥力综合评价OA

To investigate the nutrient characteristics and fertility of tobacco-planting soils in central Henan,a total of 231 typical surface soil samples(0-20 cm depth)were collected from tobacco fields in Xuchang City(Xiangcheng,Jian'an,Yuzhou),Pingdingshan City(Baofeng,Ruzhou,Yexian),and Luohe City(Linying,Wuyang,urban area)for testing.Principal component analysis and cluster analysis were employed to analyze the nutrient characteristics and comprehensive fertility of the soil samples.The results showed that the tobacco-planting soils in central Henan were weakly alkaline.Among the soil nutrients,the contents of organic matter,alkali-hydrolyzable nitrogen,and available phosphorus were at a medium level,the content of available potassium was relatively sufficient,while the content of water-soluble chloride ions was relatively high.Principal component analysis results indicated that the overall fertility of the tobacco-planting soils was at a medium-to-low level.The ranking of the Comprehensive Fertility Index(IFI)of soils in each city was as follows:Pingdingshan(0.24)>Luohe(0.21)>Xuchang(-0.31).Cluster analysis classified the aforementioned tobacco-planting soils into four categories:Category Ⅰ:Soil pH was near neutral,with relatively high contents of alkali-hydrolyzable nitrogen and available phosphorus,and slightly high content of water-soluble chloride ions;Category Ⅱ:Soil was weakly alkaline,with relatively high levels of both soil nutrients and chloride ions;Category Ⅲ:Soil had a relatively high pH value and a low content of alkali-hydrolyzable nitrogen;Category Ⅳ:Soil had low contents of both available potassium and water-soluble chloride ions.