【摘要】 为了进一步研究施用氮肥对夏玉米氮素利用及土壤硝态氮积累的影响,寻求夏玉米合理施氮量,以‘郑单958’为试材进行大田试验,研究施氮量对夏玉米氮素利用及土壤硝态氮积累变化的影响。结果表明,施氮量在0～260kg/hm2范围内,夏玉米产量随其增加显著提高,当施氮量高于260kg/hm2时,产量有减少趋势;氮素的利用率随施氮量的增加也逐渐降低。在玉米整个生育时期土壤硝态氮含量呈现先下降而后缓慢上升的趋势,随着施氮量增加,各土层硝态氮含量提高。适量施氮可促进玉米对氮素的吸收利用,进而提高玉米产量,但过量施氮导致硝态氮在土壤中大量积累,增大了污染环境风险。在超高产栽培条件下,从玉米产量、氮素利用率和土壤硝态氮积累情况综合考虑,夏玉米合理施氮量应控制在195～260kg/hm2范围之内。更多还原

【Abstract】 A field experiment was carried out, for further study on the effect of nitrogen fertilization on nitrogen use efficiency by summer corn and on the accumulation of soil nitrate nitrogen to seek for reasonable amount of nitrogen fertilization to summer corn, with ‘ Zhengdan 958 ’ as the trial material to study the effect of the amount of nitrogen fertilization on nitrogen use efficiency by summer corn and on the change of the accumulation of soil nitrate nitrogen. The results showed that, the yield of summer corn remarkably improves as nitrogen fertilization increased when the fertilizing amount ranges from 0 kg/hm2 to 260 kg/hm2 . When the fertilizing amount was above 260 kg/hm2 , the yield tends to reduce, and the nitrogen use efficiency by summer corn drops gradually along with the increase of nitrogen fertilization. During the whole process of growth of summer corn, the content of soil nitrate nitrogen showed a tendency of lowering first and then rising slowly. With the increase of nitrogen fertilization, the content of nitrate nitrogen in all soil layers increases correspondingly. Fertilizing appropriate amount of nitrogen could promote nitrogen absorption by summer corn and thereby raise the yield of summer corn. While too much nitrogen would lead to a large quantity of accumulation of nitrate nitrogen in the soil so that the risk of polluting the environment increased. This experiment indicated that, the appropriate amount of nitrogen fertilization into summer corn should be controlled in the range of 195-260 kg/hm2 under the condition of super-high yield cultivation with an overall consideration of corn yield, nitrogen use efficiency and the accumulation of soil nitrate nitrogen.更多还原