玉米光合特性和冠层微环境对密度和行株距配置的响应

适宜密度及行株距配置可构建合理的玉米群体和冠层结构,提高光合效率,系统分析玉米光合特性及冠层微环境对密度和行株距配置的响应机制,为华北平原玉米光温高效生产提供科学依据。试验采用裂区设计,主区设密度6.75万株/hm ²（D1）和8.25万株/hm ²（D2）,副区为3种行株距配置:60cm等行距（H1）、宽窄行80cm+40cm（H2）、匀播（H3）38cm（行株距相同,D1）和34.5cm（行株距相同,D2）。结果表明:常规生产密度等行距（D1H1）种植和高密度宽窄行（D2H2）种植能形成合理的群体冠层结构,具有适宜的冠层温度、CO₂浓度和相对湿度,能促进植株对光能的吸收和利用,提高净光合速率,从而获得较高的产量。因此,在常规密度等行距种植基础上,进一步增加密度至8.25万株/hm ²时,宽窄行种植方式具有较高的产量潜力。

Response of Photosynthetic Characteristics and Canopy Micro-Environment to Planting Density and Row Spacing of Maize(Zea Mays L.)

Reasonable density and rowing spacing allocation can build reasonable population structure of maize and improve photosynthetic efficiency. In order to provide scientific basis for high efficiency of radiation and temperature on production of maize in North China Plain, the response mechanism of the photosynthetic characteristics of the maize and the canopy microenvironment in response to to the density and row spacing was systematically analyzed. The experiment was designed to analyse two densities 67 500 plant/ha (D1), 82 500 plant/ha (D2) and three row spacing 60cm+60cm (H1), 80cm+40cm (H2), 38cm+38cm or 34.5cm+34.5cm (H3). The results showed that conventional planting density (D1H1) and high density planting (D2H2) have better canopy structure, suitable canopy temperature, CO₂ concentration and relative humidity, these two planting manners could promote the utilization of light radiation and increase the photosynthetic rate, so they got higher yields. Therefore, on the basis of conventional planting density and equal row spacing, when the density is increased to 82 500 plant/ha wide and narrow row spacing has higher yield potential when the density is further increased.