密度对高产夏玉米产量和氮素利用效率的影响

选用登海661和超试11为试验材料,研究种植密度对高产夏玉米产量和氮素利用率的影响。结果表明,随密度的增加产量先增加后降低,登海661在密度为12万株/hm2时产量最高,为11 292 kg/hm2;氮肥偏生产力随密度的增加先升高后降低,在密度为12万株/hm2时达最大,为37.64 kg/kg;总氮素积累量在3.0万～10.5万株/hm2范围内先增加后降低,进一步增加种植密度后总氮素积累量增加;低密度条件下氮素利用率较高,随密度升高呈降低趋势;氮素收获指数随密度增加先增加后降低,在12万株/hm2时达最大值。本试验条件下,获得较高产量和氮素利用效率的适宜种植密度为7.5万～10.5万株/hm2。

Effects of Plant Density on Grain Yield and Nitrogen Use Efficiency of the Summer Maize with High Yield

Effects of plant density on grain yield and nitrogen use efficiency of summer maize under high yield condition are studied.Summer maize cultivar DH661 and CS11 were used for experimental materials.The results showed that the grain yield increased at first,then decreased with the increment of plant density.At the plant density of 120 000 plant/ha,the grain yield of DH661 was the highest,being 11 292 kg/ha.Nitrogen partial factor productivity(PFP) and the amount of total nitrogen accumulation(TNAA) in plant increased at first,then decreased,and reached the highest at the plant density of 120 000 plant/ha,37.64 kg/kg for nitrogen partial factor productivity,and the amount of total nitrogen accumulation in plant among the plant density of 30 000 plant/ha to 105 000 plant/ha increased at first,then decreased.And with the density increase,the amount of total nitrogen accumulation in plant increased again.Nitrogen utilization efficiency(NUE) was high under low density condition,with the plant density increasing,nitrogen utilization efficiency(NUE) increased at first,then decreased.Nitrogen harvest index(NHI) increased at first,then decreased with the density increasing,and reached the highest at the plant density of 120 000 plant/ha.As a result,increasing the plant density could improve grain yield and nitrogen use efficiency.In conclusion,under this field experiment conditions,as far as grain yield and nitrogen use efficiency are concerned,the most optimal density are 75 000-105 000 plant/ha.