我国烤烟生产中的氮素管理及其与烟叶品质的关系

在诸多营养元素中,氮素既是土壤中最不稳定的元素,也是影响烟叶产量和品质最为重要的元素。为追求产量,在我国目前的烤烟生产中氮肥施用过量的现象较为普遍。施氮量过高往往造成烟叶品质下降。生产中普遍推荐的肥料施用技术所提供的氮素与烟株生长的需氮规律不吻合。生长后期土壤氮素矿化使得烟株生长过程中的氮素营养难以控制,并缺乏有效的检测手段。目前对于造成烟叶中烟碱含量升高的真正原因没有正确认识。结合我们的研究,本文就我国烤烟生产中存在的上述问题进行分析与讨论。旨在通过努力达到烤烟生产中的氮素营养平衡,烟叶的化学成分趋于协调,并达到提高氮肥利用率、减少环境污染的目的。

Nitrogen management and its relation to leaf quality in production of flue-cured tobacco in China

Among nutrients necessary for plant growth, nitrogen is both the most unstable in soil, and the most important for the yield and the quality of tobacco leaves. For obtaining high yield of tobacco leaves, over-fertilization of nitrogen in present tobacco production in China was very common, which often caused reduction of the quality of tobacco leaves. The dosage and the time of nitrogen supply according to the present recommendation for the application rate of chemical fertilizer nitrogen can not meet the demand of tobacco plant for nitrogen. Soil nitrogen mineralization at the late growth stage of plant makes it difficult to manage nitrogen during the plant growth, and the suitable method to control the nitrogen status in plant is also lack. The understanding of the reason for the increased nicotine concentration in tobacco leaves is not correct. Accordingly, in this paper, the topics of optimal application rate and time of fertilizer N, rapid plant nitrate test, soil nitrogen mineralization at the late growth stage of plant, and the relations between application rate N fertilizer and nicotine content in tobacco leaves are discussed.