基于主成分分析的海南橡胶园土壤化学肥力的评价

为了掌握海南岛橡胶园土壤肥力状况，科学管理胶园，以海南省主要植胶市县144份土壤样品的数据为基础数据，采用主成分分析方法，以5项因子（土壤pH值、有机质、全氮、速效磷和速效钾）为评价指标，对胶园土壤化学肥力进行了评价与分析。结果表明:（1）主要植胶市县土壤化学肥力综合得分（IFI）为?9.08～16.79，依据综合得分结合ward聚类法可将海南岛橡胶园土壤肥力划分为高（IFI:3.29～16.79）、中（IFI:?1.8～2.74）、低（IFI:?9.08～?2.0）3个肥力水平；（2）各市县橡胶园土壤化学肥力存在较大差异，琼中县和琼海市肥力较高，屯昌县和儋州市胶园土壤肥力处于中等水平，临高县和澄迈县土壤化学肥力较低，而白沙县胶园土壤肥力出现两级分化；（3）土壤有机质和全氮是海南省橡胶园土壤化学肥力的主要限制因子，其次为速效钾。

Evaluation of soil chemical fertility in Hainan rubber plantations based on principal component analysis

A good understanding of soil fertility in the rubber plantations in Hainan Province is very important to well manage the rubber plantations for higher rubber yield through fertilizer application. In this study 144 soil samples were collected from rubber plantations in major rubber producing cities and counties of Hainan Province, and their soil pH, and contents of organic matter, total nitrogen, available phosphorus and available potassium were determined to evaluate and analyze the soil chemical fertility of rubber plantations by using the principal component analysis (PCA). The results showed that the values of the integrated fertility index (IFI) of the soil chemical fertility in the main rubber producing areas ranged from ?9.08 to 16.79. According to the IFI values and the Ward’s method, the soil fertility of rubber plantations in Hainan Island can be divided into three levels: high (IFI: 3.29～16.79), medium (IFI: ?1.8～2.74) and low (IFI: ?9.08～2.0). The soil chemical fertility varied greatly in the rubber plantations in different major rubber producing cities and counties, higher in Qiongzhong and Qionghai, moderate in Tunchang and Danzhou and lower in Lingao and Chengmai, and the soil chemical fertility in the rubber plantations in Baisha was highly different. Soil organic matter and total nitrogen are the main limiting factors for soil chemical fertility in the rubber plantations in Hainan Province, followed by available potassium. It is suggested that organic fertilizer and potassium fertilizer should be applied to improve the soil chemical fertility in the rubber plantations of different cities/counties of Hainan Province.