秸秆还田对烤烟根系活力和碳氮代谢生理特性的影响

为解决长期连作及施用化肥带来的植烟土壤环境恶化问题，在粤北烟区开展了秸秆还田对烤烟根系活力和碳氮代谢生理特性影响的研究。结果表明：水稻、花生秸秆还田处理的烤烟根系活力均显著提高，且成熟期根系衰老速度延缓，施用2500 kg/hm2花生秸秆的烤烟根系活力最强。打顶前（移栽后55天）秸秆还田处理叶片中淀粉酶、硝酸还原酶活性显著高于对照，且淀粉酶活性高峰提早10天；成熟期淀粉酶、硝酸还原酶、酸性蔗糖转化酶活性则显著降低，Inv/NR比值升高。水稻秸秆还田处理的硝酸还原酶活性高于花生秸秆还田处理，且打顶前秸秆还田量高的处理高于秸秆还田量低的处理。

Effects of Straw-returning on Root Activity and Physiological Characteristics of Carbon-nitrogen Metabolism of Flue-cured Tobacco

In order to solve the problem caused by continuous cropping and chemical lertlhzer appllcation, mls 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 2500 kg/hm2 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 the 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.