Evaluation of Soil Fertility Characteristic for Panax notoginseng Planting Area

We investigated and evaluated soil fertility of the main Panax notoginseng planting area to provide scientific basis for the cultivation and fertilization of P. notoginseng and further improve the evaluation system for soil fertility of P. notoginseng. Eighteen soil nutrient indices of 57 soil samples from Yunnan and Guangxi province were examined. A comprehensive evaluation of the soil fertility was carried out by the methods of principal component analysis,fuzzy math and clustering analysis. The results showed that the average content of soil organic matter was relatively higher,but some were slightly lower. The contents of total nitrogen(N),available N,total phosphorus(P),available P,available potassium(K) were relatively higher than medium. The calcium( Ca),magnesium( Mg), sulphur(S) and the micronutrient elements were higher than medium,except the content of available B was lower than medium. The nutrient status in the soil varied widely and the coefficient of variationof various nutrients was from 12. 93% to 118. 05%. By the clustering analysis of integrated fertility index,the soil fertility of the area was classified into five different soil fertility grades,namely the highest,higher,medium,lower and lowest. The highest,higher and medium soil fertility grades accounted for 66. 67% of the samples. The research conclusion was that the soil fertility of the main P. notoginseng planting area was between high level and medium; the comprehensive evaluation methods could improve the evaluation of soil fertility quantitatively and scientifically,thereby reduce the influence of subjective factors.