Abstract:

The paper aims to study the effects of different kinds of tobacco-rape rotation and balanced fertilization on soil potassium supply capacity. A two-factor split plot experiment was designed, including main factors (winter fallow, ‘Chongrongyou 1’, ‘Deyouzao 1’and ‘GSX-1’) and by-factors (conventional fertilization, nitrogen reduction and phosphorus increase), to analyze the content of soil available potassium and potassium in tobacco leaves. The results showed that tobacco-rape rotation could improve soil available potassium content to different degrees, and the effect was the most significant in the early stage of rape transplanting (30 days), which was 1.43-2.05 times that of winter fallow treatment. With the advance of rape growth period, the effect of rotation on soil available potassium content decreased sharply, and the effect of different rape varieties on soil available potassium was as follows: ‘Chongrongyou 1’> ‘GSX-1’> ‘Deyouzao 1’> winter fallow. From the early stage of transplanting to harvest of tobacco, the content of soil available potassium decreased by 15.71%-117.80%. Except individual treatments, the content of soil available potassium and tobacco leaf potassium in tobacco-rape rotation were higher than those in winter fallow treatment, and the effect of phosphorus increase on potassium increase was the best. In conclusion, the content of soil available potassium and tobacco leaf potassium are relatively high under ‘Chongrongyou 1’- tobacco rotation and phosphorus increase, which is a good local cropping system.

Key words: tobacco-rape rotation, rape variety, balanced fertilization, soil potassium content, tobacco leaf potassium content