Comprehensive Evaluation of the Status of Soil Fertility in Tobacco-growing Demonstration Areas of Guizhou Eastern

Using the principal component analysis method,the weights of soil pH,organic matter,available nitrogen,available phosphorus and available potassium were determined for a comprehensive evaluation of the status of soil fertility in tobacco-growing demonstration areas of East Guizhou.The results showed that soil pH of most demonstration areas was neutral,a bit higher of available nitrogen content,rich organic matter content,overall low-level effective phosphorus and extremely uneven distribution,plentiful available potassium content and large-degree variation.Generally,soil fertility level of the demonstration areas was relatively a bit high,but the proportion of land above moderate soil fertility was 92.02 %,low fertility level of soil sample also had a large proportion(31.25 %) and no soil sample belonged to high fertility level.Corresponding measures should be taken to improve the soil fertility and to make it more suitable for growing tobacco.