氮素对燕麦冠层结构及光合特性的影响

为了研究氮素对燕麦坝莜1号的冠层结构、光合特性及产量的影响,用红外气体分析仪和冠层分析仪测定不同氮肥处理下群体的冠层结构和光合特性,同时分析了不同氮素水平下产量性状指标之间的差异性。结果表明:随着施氮量的增加,单株叶面积和叶绿素含量均显著增加,单株叶面积在整个生育期呈"M"型变化,叶绿素含量在抽穗期达到最大值。施氮量对叶面积指数和透光率的影响呈相反的变化趋势,随着施氮量的增加,叶面积指数变大,而透光率变小。随着施氮量的增加,燕麦坝莜1号旗叶净光合速率、气孔导度和蒸腾速率显著提高,胞间CO2浓度则降低。产量以N2处理(144.0 kg/hm2)最高。因此认为,合理的氮肥用量能显著改善燕麦群体的冠层结构,提高光合效率,是燕麦增产的重要农艺措施。

Effects of Nitrogen Fertilizer Rate on Oat Photosynthetic Character and Canopy Structure

The canopy structure and photosynthetic characteristics of oats with different fertilizer treatment were contrasting studied with an infrared CO2 analyzer and canopy analyzer in the Naked dam oat1.Analysis the difference between levels of nitrogen yield characters indicator.The results showed that chlorophyll content and leaves area per plant were clearly increased with increasing nitrogen fertilizer application.Leaves area per plant in all mature stages showed "M"change trend,the maximum chlorophyll content stage was at heading.Effects of nitrogen fertilizer rate on oat canopy LAI and DIFN showed contrary change trend,LAI became larger but DIFN became smaller with increasing nitrogen fertilizer application.Net photosynthetic rate,stomatal conductance and transpiration rate in oat fag leaves increased significantly but intercellular CO2 concentration decreased when we apply nitrogen fertilize.So a reasonable amount of nitrogen fertilizer can be significantly improved oat groups canopy structure,and increase photosynthetic efficiency.It is one of oat production important agronomic measures.