氮肥形态对不同持绿性玉米品种产量及叶片光合氮素的影响

以成单30(CD30)和正红505(ZH505)为试验材料，研究在无氮(N1)和纯氮225kg/hm²的NH4Cl(N2)、KNO₃(N3)、尿素(N4)、猪粪(N5)等5种处理下的产量、氮效率以及花后叶片氮素的变化。结果表明，氮肥显著影响玉米产量，其变化为N4>N3>N2>N5>N1。品种间产量和吸氮量没有显著差异，ZH505的氮素收获指数显著高于CD30，CD30的保绿度显著高于ZH505。氮肥形态和品种显著影响Chla和Chlb的变化，其中N4处理下含量最高，CD30显著高于ZH505。叶片氮浓度在花后20d达到最高值，两个品种在花后40d的Chla和Chlb平均含量较花后20d分别降低19.11%、13.63%和42.98%、36.31%。氮肥形态显著影响Rubisco和PEPC的变化，其中N5处理显著高于N4处理。因此根据玉米品种持绿特性，通过尿素和有机肥配合施用，提高叶片光合氮素利用效率是实现玉米高产氮高效的途径。

Effects of Nitrogen Forms on Yield and Photosynthetic Nitrogen in Different Stay-green Maize Cultivars

Chengdan 30(CD30) and Zhenghong505(ZH505) were used as test materials to study the yield, nitrogen efficiency and post-flowering leaf nitrogen changes under five treatments of NH4Cl(N2), KNO₃(N3), urea(N4) and pig manure(N5) with no nitrogen(N1) and N 225 kg/ha. The results showed that, the form of N fertilizer significantly affects yield, the yield is N4>N3>N2>N5>N1. The N harvested index of ZH505 was higher than that of CD30, and the stay-green degree of CD30 was higher than that of ZH505.The leaf N concentration reached the highest value at 20 days after silking(DAS) The N form and variety significantly affect the value of Chl a and Chl b. The content of Chl a and Chl b were the highest under N4. The concentration of Chl a and Chl b in CD30 was significantly higher than that of ZH505. The average concentration of Chl a and Chl b of the two cultivars at 40DAS was reduced by 19.11%, 13.63% and 42.98%, 36.31% respectively compared with 20DAS. The form of N significantly affects the changes of Rubisco, and PEPC, and the N5 treatment is significantly higher than that of N4 treatment. So, according to the trait of stay green, the combined application of urea and organic fertilizer is a way to achieve high yield and high nutrient efficiency of maize.