Abstract:

In order to solve the problem caused by continuous cropping and chemical fertilizer application,this research studied the effects of rice and peanut straw-returning on the activities of root and some physiological characters of carbon-nitrogen metabolism of flue-cured tobacco in northern Guangdong tobacco-planting area. The results showed that: rice and peanut straw-returning effectively improved the activities of root of flue-cured tobacco, made root aging speed slower in mature stage, the maximum activity of root happened at 2500kg/ha peanut straw-returning. Rice and peanut straw-returning could obviously improve the activities of amylase and nitrate reductase of tobacco leaf before topping stage(55 days after transplanting), the activities of amylase reached their peaks 10 days earlier than that of control. The activities of amylase, nitrate reductase and invertase of tobacco leaf decreased, the Inv/NR increased during mature stage. In our experiment，the activities of nitrate reductase of rice straw-returning treatments were higher than that of peanut straw-returning treatments, and also higher when the amount of straw applied more before topping stage.