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作 者 ：董守坤, 龚振平, 祖伟

期 刊 ：植物营养与肥料学报 2010年 16卷 1期 页码：65-70

关键词：大豆；氮素；外源氮；根瘤固氮；产量；

Keywords:exogenous-N, nodulation-N, yield,

摘 要 ：以“东农47”为试材，采用¹⁵N 标记的 (NH4)2SO4作为氮源，利用砂培方式研究了氮素营养水平对大豆氮素积累及产量的影响。结果表明，随外源氮水平增加，大豆植株氮素积累量和产量呈先增加后降低的变化趋势，当营养液氮浓度为50 mg/L时，植株氮素积累量和子粒产量最大。在 R4和 R5 期补充氮肥的供给明显增加植株对氮的积累，并能显著提高大豆产量。大豆生长需要一定量的“启动氮”，“启动氮”的作用维持到V3期对大豆氮的积累和产量形成效果最好。随外源氮水平增加，大豆吸收外源氮的比例增加，根瘤固氮所占比例降低，外源氮和根瘤固氮积累量随外源氮水平增加呈先增加后降低的变化趋势。当氮浓度为100 mg/L时，有利于植株对外源氮的吸收，当氮浓度为50 mg/L时，有利于根瘤固氮的积累，“启动氮”的作用维持到V3期根瘤固氮的积累明显增加； 在R4和R5期补充外源氮的供给可以显著增加对外源氮利用，以R5期效果最好。

Abstract:Labeled 15N ammonium sulfate was used as nitrogen source to study the effects of nitrogen nutrition levels on soybean (cultivar Dongnong 47) N-accumulation and yields using the sand culture. The results show that the crop N-accumulation and yields are increased earlier and decreased later as the exogenous-N levels are gradually increased, and the crop N-accumulation and yield are the highest when the nitrogen concentration is 50 mg/L. Applying N fertilizer during the R4 and R5 periods could increase the crop N-accumulation and yield significantly. Soybean growth and development needs “startup-N”, and the best effect of the “startup-N” on the soybean N-accumulation is until the V3 period. Proportion of soybean absorption of exogenous-N is increased when enhancing the application level of the exogenous-N, while proportion of nodulation-N is decreased. The accumulation of the exogenous-N and accumulation of nodulation-N are increased earlier, and decreased later. The accumulation of exogenous-N is the main source when the nitrogen concentration is 100 mg/L, while the accumulation of nodulation-N is the main source when the nitrogen concentration is 50 mg/L. The accumulation of exogenous-N and accumulation of nodulation-N are increased apparently when continuously using “startup-N” until the V3 period. The exogenous-N absorption is increased apparently when high level of exogenous-N is applied during the R4 and R5 periods.

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