减施氮肥运筹对棉花冠层光合有效辐射及产量的影响

【目的】 通过减施氮肥运筹调控棉花生育期获得的光合有效辐射(PAR),分析各生育时期棉花APAR和FAPAR与产量的关系,提高棉花群体绿色光能利用率和产量。【方法】 5个施氮处理施基肥量一致,对不同处理的追氮肥量进行按比例减施,并监测各生育时期棉花群体光合有效辐射。【结果】 5个施氮处理的棉花APAR和FAPAR在生育期的变化规律相似,其值从蕾期逐渐上升,至盛花期和花铃期达到较高水平,随后逐渐降低,至吐絮期降到最低水平;按高低排列依次是N₁＞N₂＞N₃＞N₄＞N₅,并且棉花的APAR和FAPAR与籽棉产量存在极显著的正相关性。【结论】 减施氮肥运筹对棉花APAR和FAPAR的动态变化产生重要影响,可以利用其在生育期的变化特征来优化棉花群体冠层结构和提高产量。

Effects of Nitrogen Fertilizer Reduction Regulation on Cotton Canopy Photosynthetic Effective Radiation and Yield

【Objective】 Based on the photosynthesis effective radiation (PAR) obtained by reducing the application of nitrogen fertilizer to regulate cotton growth, this project aims to study the relationship between cotton APAR and FAPAR and yield in the hope of improving the cotton group light energy utilization ratio and yield.【Method】 The same amount of basal fertilizer was applied to the five nitrogen treatments, and the nitrogen fertilizer was reduced in proportion to different treatments, and the photosynthetic effective radiation of cotton population was monitored at each growth stage.【Result】 The changes of APAR and FAPAR in the growth stage of 5 nitrogenous cotton plants were similar. The values of APAR and FAPAR increased gradually from bud stage to flowering stage and bolling stage, and then decreased gradually to the lowest level at wadding stage. The ranking order was: N₁>N₂>N₃>N₄>N₅, and APAR and FAPAR of cotton had extremely significant positive correlation with seed cotton yield.【Conclusion】 Nitrogen reduction regulation has an important effect on the dynamic changes of cotton APAR and FAPAR, and the canopy structure of cotton population can be optimized and yield can be increased by using its changing characteristics in the growth period.