Study on Content of Organic Matter and Nitrogen in Wenshan Tobacco Growing Soils

To understand the tobacco-growing soil nutrient status and scientific guidance balanceable fertilize in Wenshan tobacco growing area,the nutrient contents of 134 soil samples from Wenshan tobacco-growing area were measured in 2011 and 2013,and the effects of different counties and altitude on soil organic matter(SOM, total nitrogen(TN) and available nitrogen(AN)content were analyzed. The results showed that:(1) the average content of SOM,TN and AN were 25.81g/kg, 0.12% and 130.18mg/kg, respectively in 2013;the average content of SOM, TN and AN were 7.22g/kg,0.13% and 136.75mg/kg, respectively,in 2011.(2) The average content of SOM and TN and AN were higher in the Xichou and Malipo Counties, those were lower in Guangnan and Yanshan Counties, but the average levels were still in the appropriate range.(3) The content of SOM and AN showed increases trend with altitude rising, while the TN in soil showed no significant.(4) Highly significant positive correlation were found between SOC and available N and available P and available K and available Cu and available Zn and available Fe and available B and Cl-(P0.01). These results suggested that the average content of soil organic matter and nitrogen are in the appropriate range in Wenshan tobacco growing area, but due to difference of regional and altitude, resulting in a greater coefficient of variation of soil organic matter and nitrogen content, therefore, in the cultivation of tobacco should be rational fertilization depending on local conditions.