施氮量对辽宁省草甸土区春玉米产量和氮利用率的影响

Effects of N Application Rate on Maize Yield and N Use Efficiency in Meadow Soil in Liaoning Province

以两个玉米品种良玉99和美联178为材料,开展连续两年田间实验,在辽宁省中部平原地区研究不同施氮量(0~300 kg/hm^(2))对玉米产量和氮利用率的影响及氮效率基因型差异。结果表明,玉米氮效率存在显著的品种间差异。施氮量与玉米产量呈“直线+平台”的函数关系。两年平均,良玉99的最高产量(12241 kg/hm^(2))高于美联178(10530 kg/hm^(2)),达到最高产量的施氮量(160 kg/hm^(2))低于美联178(201 kg/hm^(2))。利用氮高效品种可在较低氮肥投入条件下获得较高产量,显著提高氮素利用效率。在该地区玉米产量水平下,最佳玉米施氮量为148~211 kg/hm^(2)。

Two maize cultivars,Liangyu 99 and Meilian178,were grown under the different nitrogen levels(0,60,120,180,240,300 kg/ha,respectively),for a field experiment was carried out for two consecutive years to test the effect of nitrogen application on maize yield and the genotypic difference in the middle plain of Liaoning.The results showed there is significant genotypic difference in N use efficiency in maize.There is a“linear+plateau”relationship between N rates and grain yield.On average,the maximum yield of Liangyu 99(12441 kg/ha)was much higher than that of Meilian178(10530 kg/ha).However,the corresponding N rates for the maximum yield was much lower for Liangyu 99(160 kg/ha)than for Meilian178(201 kg/ha).Therefore,a N efficient cultivar can get higher grain yield with lower N input,so as to increase N use efficiency.Under the current yield level and soil nutrient conditions,the optimal N rate is suggested to be between 148-211 kg/ha.