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 tobaccotopsoil 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/TiON ratio was increased 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 Y J＞ 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-topso
[Objective] The present experiment was conducted to study the effects of bamboo vinegar on seed germination and seedling growth of different flue-cured to- bacco varieties, so as to provide some references for its application in tobacco pro- duction. [Method] By using indoor culture dish method and greenhouse seedling- raising plate culture,four different concentrations of bamboo vinegar dilution （50, 100, 200 and 400 times）were designed and clean water was used as the control （CK）. The germination indices of Yunyan 97, Guiyan 2, Jiucaiping 2 and Bina 1 were de- termined after seed germinating. The seedling growth indices of Yunyan 97 were investigated after 10 days of spaying bamboo vinegar on seedling leaves at the 3r~ time. [Result] Compared with CK, different bamboo vinegar dilutions could inhibit the seed germination and seedling growth of all flue-cured tobacco varieties. The seed germination rate and index, vigor index, whole length, root length, stem length and fresh weight of seedlings of all varieties presented decreasing trend to varying de- grees, moreover, most of them reached significant level. Compared with CK, spray- ing different concentrations of bamboo vinegar dilution at the seedling stage could improve the quality of seedlings. In all bamboo vinegar treatments, the plant height, the maximum leaf length and root volume under 100 times dilution treatment were the highest with 3.36 and 10.14 cm, and 0.92 ml, respectively. And the stem girth, dry weight and the maximum leaf width of seedlings under 400 times dilution treat- ment also showed the highest with 1.82 cm, 0.262 g and 5.74 cm, respectively. [Conclusion] Supplying different concentrations of bamboo vinegar solution on culture dish could inhibit the seed germination and seedling growth of flue-cured tobacco, while spraying 100-400 times bamboo vinegar solution to leaves could promote the seedling growth and improve the quality of Yunyan 97 to varying degrees.
