Abstract:

To explore the effects of tobacco-rape rotation and balanced fertilization on soil organic carbon (SOC) content, a two-factor split plot design, which included tobacco rotation with three rape varieties (‘Chongrongyou 1’, ‘Deyouzao 1’ and ‘GSX-1’) and balanced fertilization (nitrogen reduction and phosphorus increase), was adopted to analyze the content of soil total organic carbon (TOC) and dissolved organic carbon (DOC) in rape season and tobacco season. The results showed that from the initial stage of rape transplanting to harvest, the SOC content increased to varying degrees, ranging from 7.7% to 166.49%. The content of TOC and DOC of the rotation increased compared with those of the control, and the content of TOC and DOC of ‘Chongrongyou 1’during the harvest period (180 d) were the highest, which were 1.26 and 4.78 times that of the control, respectively. In the whole growth period of tobacco, except some individual treatments, the DOC content in soil showed a downward trend, while the TOC content increased. In addition, in terms of fertilization mode, nitrogen reduction treatment had the best effect. In the harvest period of tobacco, except ‘Deyouzao 1’, the TOC content of soil in nitrogen reduction treatments was the highest, which was 1.20, 1.44 and 1.02 times that of the control, respectively. In conclusion, the SOC content is relatively high under ‘Chongrongyou 1’ -tobacco rotation and nitrogen reduction, which is a good local planting system.

Key words: tobacco-rape rotation, balanced fertilization, total organic carbon, dissolved organic carbon, split plot experiment