种植密度和施氮量耦合对夏玉米干物质积累及氮肥利用率的影响
本研究以郑单958和中单909为试验材料，设置4.5万、6.75万、9.0万株/km2三种种植密度和0、100、300、500 kg/km2四种施氮水平，分析了种植密度与施氮量对夏玉米干物质积累量和氮肥利用率的影响。结果表明，玉米在种植密度达到9.0万株/km2，其叶面积指数、群体干物质积累量、总氮素积累量以及产量均显著高于4.5万株/km2密度处理。增施氮肥可显著增加玉米叶面积指数、单株干物质积累量、群体干物质积累量、总氮积累量和籽粒产量。当施氮量为N 300-500kg/km2时，叶面积指数、群体干物质积累量及产量不再提加，氮肥利用率和氮肥偏生产力大幅降低。兼顾产量和节约生产成本综合考虑，该地区种植郑单958和中单909的适宜模式为施氮量300 kg/km2、种植密度9.0万株/hm2。
英文摘要:
The dry-matter accumulation and nitrogen utilization of summer maize were investigated among the varieties of Zhengdan958 and Zhongdan909 under the different planting densities ( 45000 plant /ha, 67500 plant /ha, and 90000 plant /ha) and different nitrogen rates ( N 0 kg /ha, 100 kg /ha, 300 kg /ha and 500 kg /ha). The result showed that compared with the 45000 plant /ha treatment, the leaf area index (LAI), total dry matter accumulation, total nitrogen accumulation and grain yield in 90000 plant /ha treatment were significantly improved. The increase of nitrogen rate could effectively increase the LAI, dry matter accumulation amount per plant, biomass，total nitrogen accumulation and grain yield. LAI, total dry matter accumulation and grain yield were no more increased, the nitrogen partial factor productivity and nitrogen partial factor productivity are significantly decreased when nitrogen rate reached 300-500 kg/ha,. Considering the grain yield, conserving resources and sustainable production, the most optimal nitrogen rate and plant density of Zhengdan958 and Zhongdan909 are both N 300 kg /ha and 90000 plant /ha in this area．
查看全文
;
