湖南永顺烟区土壤养分状况的综合评价

对湖南省永顺县烟区的239个土壤样品、19项土壤养分指标进行了测定,确定了各指标所属的隶属度函数类型及其阈值,采用主成分分析法求得各指标的权重,用加乘法算出各土样的土壤肥力综合指标值(IFI),进而对永顺县植烟土壤适宜性进行了综合评价。结果表明:永顺县烟区土壤肥力存在较大的差异,其IFI值平均为0.541,变幅为0.341～0.730,变异系数5.14%。采用聚类分析法将土壤肥力分为高、较高、中等、较低4类,各类土样所占比例依次为15.86%、21.61%、44.17%、18.36%。

Comprehensive Evaluation of Soil Fertility in Yongshun Tobacco-growing Areas of Hunan Province

Nineteen soil nutrient indexes of 239 soil samples from Yongshun tobacco-growing areas of Hunan province were ana-lyzed. Types of membership function and threshold values for each fertility index were determined. The method of principal component analysis was used to calculate the weight of each fertility index, and the additive and multiplicative theorem was used to estimate the integrated fertility index (IFI) of each soil sample. The results of comprehensive evaluation indicated that there was significant varia-tion in soil fertility among different soil samples from Yongshun tobacco-growing areas, IFI values of the whole soil samples ranged from 0. 341 to 0. 730, with the mean of 0.541, and the variation coefficient of IFI was 5. 14% . The soil fertility of various soil samples could be classified into four grading, namely higher, high, medium and low grade by cluster analysis, which took up 15. 86% , 21.61% , 44. 17% and 18.36% of the total soil samples respectively.