种植密度和氮肥水平对春玉米产量及氮素效率的影响

Effect of Growing Density and Nitrogen Supply on Yield and Nitrogen Use Efficiency in Spring Maize

以玉米杂交种郑单958为材料,对不同种植密度和施氮水平下春玉米的产量形成和氮素利用效率进行了研究。结果表明,不同种植密度对郑单958子粒产量形成影响极显著,中密度水平(67500株/hm2)下,玉米单株生产能力较高,高密度(90000株/hm2)下的减产原因是干物质积累总量的减少;不同施氮水平对郑单958子粒产量形成影响显著,氮肥对玉米生产能力的调控作用主要表现在对穗粒数的影响上,适宜的氮肥施用量可促进顶部子粒发育,使秃尖长度减小,增加穗粒数,增加产量,并提高氮素的利用效率;种植密度与氮肥水平间互作效应显著。在3种密度水平(45000、67500、90000株/hm2)下,施氮量为225kg/hm2时,增产作用均最明显,是当地较为适宜的氮肥施用量。

This paper summarized the effects of growing density and nitrogen supply on yield and nitrogen use efficiency in spring maize hybrid Zhengdan 958.The results showed that significant difference in the grain yield of Zhengdan 958 was observed following the different growing densities with the production capacity was the highest in 67 500 plants/hm^2 while that of 90 000 plants/hm^2 was lower.Significant effects of nitrogen supply on yield of this variety were also demonstrated.Nitrogen supply is of great importance to improve kernel number and grain weight.Appropriate nitrogen supply could not only keep leaves with higher photosynthesis ability,but also provide more assimilate to grain.The mutual effect of growing density and nitrogen supply is prominent.Under different growing densities,nitrogen supply of 225kg/hm^2 led to the highest yield of Zhengdan 958.