行距配置和覆反光膜对夏玉米产量及光能利用的影响

Effects of Row Spacing and Mulching Reflective Film on the Yield and Light Utilization of Summer Maize

【目的】近些年来夏玉米生长期阴雨寡照时有发生,光照不足已经成为影响夏玉米生长发育的重要限制因素。本研究的目的在于探讨在高密度下,采取适当调节行距配置和覆反光膜等措施能否有效改善及优化群体冠层和内部的光环境,缓解高密度造成的遮阴加重等问题,为进一步提高玉米产量提供理论依据。【方法】于2018-2019年进行大田试验,以郑单958为试验材料,在常规密度(67 500株/hm^2)和高密度(82 500株/hm^2)条件下,设置3个行距配置((60+60)cm、(80+40)cm、(100+20)cm,覆反光膜(FM)和不覆膜(NM)2个处理,研究覆反光膜和行距配置对夏玉米光能利用及产量的影响。【结果】高密度种植,玉米产量增加。密度67 500株/hm^2时,"60+60"和"80+40"行距配置的产量无显著差异,但均高于"100+20"行距配置;但密度82 500株/hm^2时,覆反光膜处理下"FM80+40"的行距配置能够有效改善群体内部光照环境,使光能在玉米群体冠层内的分布更加合理,显著提高干物质积累量、LAI、冠层光能截获率、Pn及叶绿素含量,2年平均产量较"FM60+60"和"FM100+20"处理提高6.6%和10.8%,在不覆膜条件下"NM80+40"处理较"NM60+60"和"NM100+20"处理增产5.8%和8.7%,且"FM80+40"处理较"NM80+40"处理增产5.1%。【结论】82 500株/hm^2密度下,采用"80+40"的行距配置,辅以覆反光膜处理,可显著改善夏玉米光合特性,提高下部透射光的反光率,进而增加中下部叶片的受光,防止叶片早衰,提升光合能力,是实现夏玉米再高产较理想的栽培模式。

【Objective】In recent years, it is the limitation for summer maize to face the less light radiation during the growing season, and the light deficiency has become the main limiting factor affecting the production of maize. In this study, the row spacing under high density of maize was adjusted appropriately to improve the light in the canopy and the interior of the population and to alleviate the influence of shading caused by high density, so as to lay a foundation for further improving the yield.【Method】This experiment took Zhengdan 958 as the experimental material under field conditions in 2018-2019, and there were two different planting densities, which were 67 500 plants/hm^2 and 82 500 plants/hm^2, and three row spacing forms(60+60, 80+40, 100+20), with mulching reflective film(FM) and no film treatment(NM). The effects of mulching reflective film and row spacing on light energy utilization and yield of summer maize were studied. 【Result】As the density increases, the maize yield increased. There was no significant difference in the yield of "60+60" and "80+40" row spacing configurations when the density of 67 500 plants/hm^2 was higher than that of "100+20" row spacing configurations under the condition of mulching reflective film and no film. But at 82 500 plants/hm^2 density, the row spacing configuration of "FM80+40" under the mulching treatment could effectively improve the light environment within the population and made the distribution of light energy in the canopy more reasonable, and significantly increase the dry matter accumulation, LAI, canopy light interception rate, Pn and chlorophyll content;Compared with "FM60+60" and "FM100+20" treatments, the two-year average yield of which were increased by 6.6% and 10.8%, respectively. The yield of "NM80+40" row spacing was 5.8% and 8.7% higher than that of "NM60+60" and "NM100+20" row spacing, respectively, and the yield of "FM80+40" was 5.1% higher than that of "NM80+40".【Conclusion】Under the density of 82 500 plants/hm^2, "80+40" row spacing arrangement supplemented by mulching reflective film could significantly improve the photosynthetic characteristics of summer maize, increase the reflectance of transmitted light at the lower part, and then increase the illumination of the middle and lower part of leaves, prevent premature aging of leaves, and improve photosynthetic capacity. Therefore, this treatment was an ideal cultivation mode to achieve high yield of summer maize.