玉米定向栽植模式下冠层结构及光能分布特征研究

为探讨不同栽植模式下玉米冠层光能利用情况的差异和定向栽植方式的增产机理,以紧凑型玉米品种先玉335和半紧凑型玉米品种吉单50为试验材料,设置定向播种、随机播种、定向移栽、随机移栽4种栽植模式,测定其玉米冠层结构参数、群体内不同高度不同时间的光合有效辐射量等参数。结果表明:吐丝期最大冠层形成时两个品种叶片垂直分布比例存在差异,且不随栽植方式改变而改变。其中,上午时段(10:00~10:15)定向播种和定向移栽的群体有效光能截获率分别比随机种植模式增加10.60和23.50个百分点,但定向种植模式玉米群体的中部光合有效辐射下降快,而群体底部可保证一定的透光率;在机械许可的情况下,定向栽植能够建立合理冠层结构,有效利用光能,为高产栽培提供一条新的途径。

Canopy structure and light distribution of maize under oriented planting pattern

Parameters of maize canopy structure and photosynthetic effective radiation in different canopy height at different measured times were studied to reveal the mechanism of yield increasing under oriented planting pattern. The compact type maize Xianyu 335 and semi-compact type maize Jidan 50 were grown under oriented seeding, random seeding, oriented transplanting and random transplanting to research the photosynthetic utility and light distribution under diverse planting patterns. The results indicated that there were differences between leaf vertical distribution proportions of the two maize varieties at tasseling time, which didn''t change alone with the planting pattern. In the morning (10:00-10:15), the rate of light capture increased by 10.6% and 23.5% under orientation seeding pattern and transplanting pattern. Photosynthetic active radiations fell faster in the central of the group from 2 m to 1 m under oriented patterns than those under the random patterns and at the same time, it could guarantee a certain light transmittance at the bottom of the group in oriented patterns. In the case of convenient mechanical condition, oriented planting pattern can establish reasonable and effective canopy to use light. It will provide a new way for the high yield cultivation of maiz