【摘要】 小麦缺氮影响到叶片光合效率、叶绿素含量、含氮量，根系活力也较早的进入衰退阶段，且质量水平低下。缺氮程度越深，恶化越深。这种发生在小麦开花后的生理功能早衰，可明显影响籽粒形成和灌浆过程，致使穗粒数减少，灌浆持续期缩短，千粒重与籽粒产量明显降低。因此，保证小麦生长中后期充足的氮素供应，防止早衰是提高籽粒产量的重要途径。更多还原

【Abstract】 Lacking nitrogenous fertilizer during wheat growth can influence the photosynthetic rate and content of chlorophyll and nitrogen in leaves. It can also lead to early senescence in the root vigor, which then functions at a low level. The more nitrogen the wheat lacks, the more significant influence is made on the wheat growth. This kind of decline in physiological function, which occurred after the florescence has a negative effect on the wheat milking and formation of seed, decreases the quantity of spikes, shortens the duration time of milking, and lowers the thousand grains weight and seed production of the wheat. Therefore, sufficient nitrogenous fertilizer is an essential way to prevent early senescence in the latter period of wheat growth.更多还原