不同种植密度下缓/控释肥施肥量对夏玉米氮利用和籽粒产量影响

Effects of Controlled and Slow Release Fertilizers on the N Utilization and Grain Yield in Summer Maize Under Different Plant Densities

为了探明缓释肥施肥量对夏玉米氮积累利用和籽粒产量的影响,以夏玉米品种‘郑单958’为材料,在不同种植密度水平(6.75×104株/hm2、8.25×104株/hm2)下,以当地传统施肥量(750 kg/hm2)为对照,增加缓释肥施肥量(975 kg/hm2)进行比较研究。结果表明:缓/控释肥施肥量对夏玉米各器官及全株氮含量、氮利用效率均无显著影响;增加缓/控释肥施肥量明显降低了玉米空秆率(其均值较对照施肥量降低了20.0%),尤其是在高密度下空秆率比同密度低肥量处理降低了27.0%,单穗重也增加12.4%。缓/控释肥施肥量对产量影响虽然未达到显著水平,但高密度下增施缓/控释肥处理比对照产量增加15.0%,比同密度低肥量处理增加19.4%,经济效益也比对照增加12.3%。因此,在高密度种植(8.25×104株/hm2)下适量增加缓释肥(975 kg/hm2)更有利于挖掘夏玉米增产潜力,实现夏玉米节本增产增效。

In order to determine the effects of controlled and slow release fertilizers on the N utilization and grain yield in summer maize under different plant densities, medium and high rates of controlled and slow release fertilizer （i.e. 750 kg/hm2, 975 kg/hm2） were applied under medium and high plant densities （6.75×104, 8.25 × 104 plant/hm2）, summer maize cultivar ＇Zhengdan 958＇ was used for this study. The treatment of 750 kg/hm2 controlled and slow release fertilizer level under medium plant density （6.75×104 plant/bin2） was as control. The effect of controlled and slow release fertilizer on the N concentration in either individual plant organ or total plant was insignificant. However, the increase supply of controlled and slow release obviously deceased the plant bare rate by 20.0% compared with the medium supply of controlled and slow release fertilizer, especially under high plant density （decrease by 27.0%）, and the average ear weight increased by 12.4%. Although the effect of controlled and slow release fertilizer on grain yield was insignificant, the average yield of high supply of controlled and slow release fertilizer under high plant density was increased by 15.0%, 19.4% compared with control, and medium supply of controlled and slow release fertilizer under the same plant density, and the economic efficiency was also increased by 12.3% compared with control. It is thus concludedthat high supply of controlled and slow release fertilizer （975 kg/hm2） under the high plant density （8.25 × 104 plant/hm2） could further increase the grain yield and economic efficiency.