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在广东南雄烟区以烤烟品种K326为材料,采用田间原位培养方法和15N同位素示踪技术,在大田条件下研究了土壤氮素矿化特征、烤烟氮素累积分配规律以及当季施入肥料氮的分配情况.结果表明:南雄烟区土壤氮素矿化量随着生育期推移呈上升趋势,在移栽后75 d达到高峰,此后下降;不施氮处理土壤氮素矿化量在各生育期均显著高于施氮处理;烟株不同器官氮素积累量表现为叶片>茎>根.烤烟在团棵期和打顶期以吸收肥料氮为主,成熟期则以吸收土壤氮为主,烟株整个生育期吸收的氮素主要来源于土壤氮,且吸收的土壤氮及其占总氮的比例随生育期推移和叶片着生部位的升高而增加.氮肥烟株利用率、土壤残留率和损失率分别为30.8%、32.3%和36.9%.南雄烟区土壤氮素矿化能力较强,土壤氮对上部叶片质量的影响较大,在施氮量为150 kg.hm-2条件下,肥料氮的残留量和损失量较高.
In the tobacco growing area of Nanxiong of Guangdong province, the flue-cured tobacco cultivar K326 was used as raw material to study the characteristics of nitrogen mineralization, nitrogen accumulation and distribution in flue-cured tobacco and field application of 15N isotope tracer The results showed that the nitrogen mineralization in Nanxiong tobacco growing area increased with the growth period and reached the peak at 75 days after transplanting, and then decreased. The nitrogen mineralization of soil without nitrogen application The nitrogen accumulation in different organs of tobacco plant showed leaf> stem> root at the whole growth period.Flue-cured tobacco mainly absorbed fertilizer nitrogen during the flowering and fruiting phases, while the absorption of soil Nitrogen was the main source of N uptake during the whole growth period of tobacco plants, which was mainly derived from soil N, and the uptake of soil N and its proportion in total N increased with the growth period and the location of the leaves. The rates of soil residual and loss were 30.8%, 32.3% and 36.9%, respectively.Nanxiong tobacco soil had a strong ability of mineralization of nitrogen and soil nitrogen had a significant impact on the quality of the upper leaves. Under the nitrogen application rate of 150 kg Under the condition of .hm-2, the nitrogen content and loss of fertilizers are higher.