Effect of Different Fertilization Patterns on Carbon and Nitrogen Components of Tobacco Topsoil.

In order to explore the fertilizing ways and dynamic changes of soil carbon and nitrogen in the main producing areas of tobacco in Guizhou, research was conducted to study the variations of dissolved organic carbon and nitrogen, total organic carbon and nitrogen and their ratio of tobacco-topsoil in organic fertilization pattern and conventional cultivation pattern (No fertilizer as control) by pot experiment. The results were as follows: (1) The effects of different fertilization patterns on soil dissolved organic carbon and nitrogen and total organic carbon and nitrogen were significantly different. The content of DOC, DON, TOC and TON in tobacco-topsoil was decreased with the advancing of growth period in conventional fertilization pattern. In the conventional fertilization pattern, the accumulation of DOC and TOC was increased first and then decreased, and the accumulation of DON and TON was decreased first and then increased. (2) The TOC content at the different growing stage and DOC content at the middle and later stage of tobacco were significantly improved in organic fertilization patterns. The accumulation of DON and TON in the conventional fertilization pattern was significantly higher than those in the organic fertilizer pattern and control at the rosette stage and vigorous stage. In the harvest period, the content of DOC, DON, TOC and TON of tobacco-topsoil in the conventional fertilization and organic fertilization pattern was significantly higher than those in the control. (3)The DOC/DON ratio and the TOC/TON ratio was in- creased gradually with the advancing of growth period in conventional fertilization pattern, but they were increased first and then decreased in the organic fertilization pattern and CK. The DOC/DON and TOC/TON ratio of tobacco-topsoil in different fertilization patterns was showed as YJ> CK> CG at the different growing stage. The experiment results revealed that: The organic fertilization pattern may improve significantly the accumulation of DOC, DON, TOC and TON of tobacco-topsoil at the middle and later stage and the DOC/DON and TOC/TON ratio at the different growth stage. It contributed to the continuous and balanced supply of nutrients at the middle and later stage of tobacco and the soil fertility. [ABSTRACT FROM AUTHOR]