Abstract:
Increased aboveground biomass is contingent on enhanced photosynthetically active radiation intercepted by the canopy (IPAR), improved radiation use efficiency (RUE), or both. We investigated whether and how optimized agronomic management practices promote IPAR and RUE. Four integrated agronomic management treatments, i.e., local traditional practice (LP), improved local traditional practice (ILP), high-yield agronomic management (HY), and improved high-yield agronomic management (IHY), were compared over two wheat (Triticum aestivum L.) growing seasons. The average grain yield obtained with IHY was 96% relative to that of HY and was 7% and 23% higher than that with ILP and LP, respectively. Both HY and IHY consistently supported large values of the leaf area index and IPAR fraction, thereby increasing total IPAR. Treatment HY showed increased pre-anthesis RUE, manifested as a higher specific leaf nitrogen content and whole-plant N nutrition index at anthesis. The highest pre-anthesis aboveground biomass was obtained with HY due to the highest pre-anthesis IPAR and RUE. Along with a higher canopy apparent photosynthetic rate, IHY produced higher post-anthesis aboveground biomass due to its higher post-anthesis IPAR and RUE. Treatment IHY had a slightly lower total IPAR but a similar total RUE and harvest index, thus producing a slightly lower grain yield relative to HY. These results demonstrate that the optimized agronomic management practice used under IHY effectively enhances radiation capture and improves radiation utilization. Additionally, the net profit for IHY was higher than that for HY, ILP, and LP by 8%, 11%, and 88%, respectively. Considering the high grain yield, high RUE and high economic benefits, we recommend IHY as the agronomic management practice in the target region, although further study of improvements in pre-anthesis RUE is required.
摘要:
地上生物量的增加取决于冠层(IPAR)拦截的光合有效辐射的增强,提高辐射利用效率(RUE),或者两者兼而有之。我们调查了优化的农艺管理措施是否以及如何促进IPAR和RUE。四种综合农艺管理处理,即,当地传统做法(LP),改进当地传统做法(ILP),高产农艺管理(HY),和改善高产农艺管理(IHY),在两个小麦(TriticumaestivumL.)生长季节进行了比较。相对于HY,IHY获得的平均谷物产量为96%,比ILP和LP高7%和23%,分别。HY和IHY始终支持叶面积指数和IPAR分数的较大值,从而增加总IPAR。治疗HY显示出花前RUE增加,表现为花期比叶氮含量和全株氮营养指数较高。由于最高的花前IPAR和RUE,使用HY获得了最高的花前地上生物量。随着较高的冠层表观光合速率,IHY由于其较高的花后IPAR和RUE,产生了较高的花后地上生物量。治疗IHY的总IPAR略低,但总RUE和收获指数相似,因此,相对于HY,谷物产量略低。这些结果表明,在IHY下使用的优化农艺管理实践有效地增强了辐射捕获并提高了辐射利用率。此外,IHY的净利润高于HY,ILP,和LP的8%,11%,88%,分别。考虑到粮食产量高,高RUE和高经济效益,我们推荐IHY作为目标地区的农艺管理实践,尽管需要进一步研究花前RUE的改进。