施氮水平对大豆氮素积累与产量影响的研究

EFFECTS OF NITROGEN APPLOCATION ON YIELD AND NITROGEN ACCUMULATION IN SOYBEAN

以绥农14为材料,利用砂培和15N标记的方法研究了施氮水平对大豆氮素积累及产量的影响。结果表明:随着施氮水平的提高,大豆全株氮素积累量及叶柄、荚皮、籽粒中氮素积累量呈现先增加后下降的趋势;高氮水平增加了叶片和茎中氮素积累量,N150较N0处理叶片的氮素积累量增加了3倍,而茎增加了5倍,但减少了根中氮素积累,降低了大豆全株和籽粒中根瘤固氮量及其所占比例,降低了肥料氮和根瘤氮的收获指数,其中根中氮素积累N150较N50处理降低了60.3%,全株根瘤氮和籽粒中根瘤氮N150较N0分别降低了74.9%、85.7%,肥料氮的收获指数N150较N50降低19.8%,根瘤氮的收获指数N150较N0降低25.5%。随着施氮水平的增加,大豆产量也呈现先增加后下降的趋势,施氮水平的增加促进了大豆植株株高、结荚高度和始荚节位的显著增加,但对节数没有明显影响,N150和N0比较株高增加了55.2%,结荚高度增加了199.7%,始荚节位增加了142.9%。

Methods of sand cultre and 15N tracing were used to study the effects of nitrogen application on yield and nitrogen accumulation in soybean variety SN14. The results showed as follows： accumulated nitrogen in the whole plant, petiole,pod shell and seed increased at the beginning and then decreased with the increase of nitrogen levels; Nitrogen accumulation in leaf and stem increased in 3 and 5 times for N150 than that of N0,which indicated that high nitrogen levels promoted the nitrogen accumulation in leaf and stem,however compared with N0,nitrogen accumulation in root, Nodulation-N accumulated in the whole plant and seed of N150 decreased by 60. 3% ,74. 9% and 85. 7% respectively, and Fertilizer-N harvest index of N150 decreased,which was 19. 8% lower than that of N50,as well as Nodulation-N harvest index 25. 5% lower than that of N50. The nitrogen levels of soybean yield also firstly increased and then decreased; Compared with N0,plant height,pod height and lowest pod nodes of soybean treated with N150 increased by 55. 2% ,199. 7% and 142. 9% respectively,while no effects were found on node number.