氮肥不同追施方法对春玉米光合特性的影响

试验从高产施肥的角度研究了不同氮肥追施方法对春玉米穗位叶光合特性的影响。结果表明：各施肥条件下，净光合速率、叶绿素含量和可溶性蛋白含量随玉米生育期的推进呈现出相同的变化趋势，净光合速率呈降低趋势，而可溶性蛋白含量却先增后减。氮肥分3次平均追施（拔节期、大喇叭口期、抽穗期），可使春玉米穗位叶的净光合速率、叶绿素含量和可溶性蛋白含量较稳定，并能保持较长的高光合持续期，有效地提高玉米的光合作用，增加产量。

Effect of Different Nitrogen (N) Dressing Method of Spring Maize on Photosynthetic Traits

From the viewpoint of high-yield application of fertilizers,under different dressing method of nitrogenous fertilizer,studies were made about photosynthesis characteristic in ear-leaf of spring maize.Results indicated that under different fertilizer supply,the changing of photosynthetic rate(Pn),chlorophyll content Chl(a b) and soluble protein content(Pro) with growing stage were the same trend,the Pn declined all the time;Pro increased earlier then reduced.The additional nitrogen fertilizing by three times(the jointing stage,the bell-mouthed period,and the heading date) can keep Pn,Chl(a b) and Pro in ear-leaf of spring maize on maintenance level,and high photosynthesis stage can be prolonged,accordingly a good yield was gained.