Study on accumulation and distribution of different sources of nitrogen in flue-cured tobacco plant by 15. tracer

chinois. 了解水稻土植烟土壤供氮特征及对烤烟氮素累积分配和烟叶品质的影响。【方法】在云南省玉溪市红塔区赵桅村6组烟田和赵桅实验基地设置了田间原位矿化培养试验和大田15N示踪试验,研究在不施氮和施氮90kg・ha. 1条件下,烟株不同生育期水稻土氮素矿化特征,烤烟体内不同来源氮素的累积和分配及烟叶的产量和品质状况。【结果】6组烟田和实验基地土壤供氮能力均较强,在施氮90kg・ha. 1条件下,烟株整个生育期吸收的氮素主要来自于土壤氮,且吸收的土壤氮量及其占总吸氮量的比例随生育期延长和烟叶着生部位升高明显增加。在本试验中,尽管施氮的增产作用不显著,但显著提高了烟叶总氮和烟碱含量,改善了烟叶品质,但由于烟株生育后期土壤供氮过多,上部烟叶存在烟碱含量偏高的问题。【结论】控制烟株生育后期水稻土土壤供氮量,对提高烟叶尤其上部烟叶质量至关重要。

anglais. [Objective] This study attempted to investigate the characteristics of nitrogen supply on paddy soil and its effects on nitrogen accumulation and distribution and quality of flue-cured tobacco. [Method] In situ incubation experiment and 15. -labelled field trials were conducted to study the characteristics of soil nitrogen mineralization, the accumulation and distribution of different sources of nitrogen in flue-cured tobacco plants and the yield and quality of tobacco leaves at nitrogen rates of 0 and 90 kg・ha. 1 on paddy soil at Zhaowei Village Group 6 and Zhaowei Experiment Base in Hongta District, Yuxi City, Yunnan Province, China. [Result] The abilities of soil nitrogen mineralization were great in the fields of Group 6 and Zhaowei Experiment Base. Under the condition of applying nitrogen 90 kg・ha. 1, most nitrogen of tobacco plants derived from soil, and with growth period extending and stalk position ascending, both soil nitrogen content and the ratio to total nitrogen evidently increased. The experiments also indicated that using nitrogen fertilizer had little effect on increasing yield, but remarkably increased nitrogen and nicotine content, and improved the quality of tobacco leaves. However, the nicotine concentrations of upper leaves were too high for the excessive supplement of soil nitrogen. [Conclusion] Results of study suggests that controlling the supplement amount of soil nitrogen on paddy soil in latter period of tobacco growth is important to improve the quality of tobacco leaves, especially to upper leaves.