Abstract:
Cluster analysis was employed to classify tobacco soils in Ankang basing on the soil nutrient data from 74 villages, and the fertilizer rates were calculated for each group of soil in term of formulated fertilization. The results showed that tobacco soils in 74 villages could be clustered into 4 groups with definite diversity in contents of organic matter, available nitrogen, available phosphorus and available potassium. According to the evaluation standard of Li zhihong on nutritional status of tobacco soil in China, the four kinds of soil nutrition contents in the first cluster were low, while in the second cluster, the contents of soil organic matter was suitable, and the available nitrogen was high, others were low. In the third cluster, the content of soil organic matter was lower, and the contents of available potassium was higher, others were low. In the fourth cluster, four kinds of nutrient were higher. According to nutritional status of tobacco soil in different clusters, the expected dose rate of tobacco soil in different clusters was calculated. From the perspective of geographic distribution, the first and the third cluster were mainly in Xunyang and Baihe, the second was mainly in Pingli, the fourth was mainly in Xunyang and Pingli. Over 50 percent of villages belonged to the third cluster in Xunyang, Baihe and Shiquan, 58.33 percent of villages belonged to the second cluster in Pingli county. Basing on the different fertility characteristics in four clusters of tobacco soils, fertilizing schemes were designed.