江淮旱地玉米氮肥适宜用量研究

为了解施氮量对玉米产量的影响，以‘隆平206’为材料，采用不同的施氮水平处理玉米植株，研究施氮量对玉米产量、穗粒数、千粒重、干物质积累量、收获指数、产出投入比和氮农学效率的影响。结果表明，0 kg/hm2、75 kg/hm2、150 kg/hm2、225 kg/hm2、300 kg/hm2、375 kg/hm2施氮量下玉米产量差异显著，在0~375 kg/hm2施氮量范围内，在0~225 kg/hm2施氮量阶段，玉米的产量随着施氮量的增加而显著增加，0、75、150、225 kg/hm2施氮量水平下的玉米产量分别为7354.0、9462.5、10847.3、11352.6 kg/km2；施氮量超过225 kg/hm2后，增施氮肥对玉米产量增加影响不显著。施氮量与玉米产量存在线性加平台关系，氮肥用量和玉米产量数学模拟方程为y=23.37x+7475，x<169；y=11426，x>169(R2=0.97**，n=18)，江淮旱地的推荐施氮量为169 kg/hm2。该研究为江淮地区玉米生产的合理施氮提供了一定的理论参考依据。

The Optimum Amount of Nitrogen Fertilizer of Maize in Jianghuai Area

In order to investigate the effect of different amount of nitrogen (N) fertilizer on maize, the yield, grains per ear, 1000-grain weight, dry weight, harvest index, the ratio of return on invested, and agronomic N efficiency of corn hybrid ‘Longping 206’ (Zea mays L.) were analyzed. Results showed that, the yield of maize was significant different under different amount of N (0, 75, 150, 225, 300, 375 kg/hm2). The yield of maize increased with the augment of N from 0 kg/hm2to 225 kg/hm2. In details, when the plants was applied with 0 kg/hm2, 75 kg/hm2, 150 kg/hm2 and 225 kg/hm2, the yield were 7354.0, 9462.5, 10847.3, 11352.6 kg/km2, respectively. However, in contrast to 225 kg/hm2 N, there was no significant increase in yield when the plants were applied with 300 kg/hm2 and 375 kg/hm2. So, the relationship between nitrogen and yield were linear plus plateau. And the mathematical simulation equation was: y=23.37x+7475, x<169; y=11426, x>169 (R2=0.97**, n=18). Accordingly, the optimum amount of N in Jianghuai area was 169 kg/hm2, which layed a theoretic foundation for reasonable use of nitrogen for maize production in Jianghuai area.