施氮量对大豆抗旱生理特性及水分利用效率的影响

研究不同施氮量下大豆光合生理指标、抗旱生理指标、产量、水分利用效率及品质指标的变化.结果表明,在试验设定的三个施氮量中,光合生理指标以施氮量72 kg/hm2处理最高;抗旱生理指标除叶片相对含水量是以施氮量72 kg/hm2处理最高之外,其他如叶绿素含量及脯氨酸含量均随着施氮量的增加而升高、叶片相对电导率及丙二醛含量均随着施氮量的增加而降低;产量及水分利用效率均为施氮量72 kg/hm2处理最高,其次为施氮量117 g/hm2处理,以施氮量27 kg/hm2处理最低,施氮量72 kg/hm2处理比施氮量27 kg/hm2处理增产24.41%,叶片水分利用效率、耕层土壤水分利用效率及降水水分利用效率分别比27 kg/hm2处理提高6.22%、24.26%及24.29%;随着施氮量增加,大豆籽粒粗蛋白含量下降、磷含量、粗脂肪含量增加,117 g/hm2处理的粗蛋白含量比27kg/hm2处理降低9.34%,磷含量及粗脂肪含量比27 kg/hm2处理提高29.25%及23.49%.总之,适当增施氮肥在一定程度上弥补了干旱胁迫对植株生长发育及代谢活性所造成的伤害,明显改善大豆的光合特性,提高了大豆的抗旱能力,进而提高了大豆产量和水分利用效率,并提高大豆籽粒的粗脂肪含量,在一定程度上改善了大豆的品质,但施氮量不宜过高,否则对大豆产生不良影响.

THE EFFECTS OF NITROGEN ON PHYSIOLOGICAL INDEXES OF DROUGHT TOLERANCE AND WATER USE EFFICIENCY IN SOYBEAN

In the paper,the physiological indexes for drought tolerance,WUE,yield and quality of soybean in different nitrogen use were studied.In the three treatments of nitrogen,which were 27 kg/hm2(N1),72 kg/hm2(N2),117 kg/hm2(N3),the photosynthesis index and leaf water content of N2 were the highest,the chlorophyll content and proline content increased with the more nitrogen using,while the MDA and REC content deceased.The water use efficiency and yield of N2 were the largest,and next was N3,the N1was the smallest,the yield of N2 were 24.29% larger than N1,the water use efficiency of leaf,soil and rainfall in N2 were 6.22%,24.26% and 24.29% higher than N1.The crude protein content of seed was decreased with the more nitrogen using,while the P and crude fat content were increased,the crude protein content of N3 was 9.34% lower than N1,the P and crude fat content of N3 was 29.25% and 23.49 lower than N1.In all,more nitrogen use can make up the harmless of dry to plant growth,improve the photosynthesis index,drought tolerance and WUE,and finally increase the yield and quality.But it was not suitable to much nitrogen use,otherwise,it can result in the negative effects.