氮肥基追比对啤酒大麦花后叶片光合特性、干物质分配及产量的影响

在江苏南京和盐城两生态点研究总施氮量为225 kg·hm-2条件下,氮肥基追比对苏啤3和单2两个大麦品种花后叶片光合特性、干物质分配及产量的影响.结果表明:大麦花后叶片净光合速率、叶面积指数、花后干物质转运量及对籽粒贡献率均随着氮肥基追比先升高后降低,在氮肥基追比为7∶3时达到最大.大麦籽粒产量亦呈现相同的趋势,以氮肥基追比7∶3处理的产量最高.进一步分析表明,采用合理的氮肥基追比、保持花后较高的光合速率有利于提高花后干物质积累和再分配,最终提高籽粒产量.

Effects of ratios of basal to topdressed nitrogen on post-anthesis photosynthesis,dry matter distribution and grain yield in malting barley

Two malting barley cultivars, Supi 3 and Dan 2, were planted in two eco-sites, Nanjing and Yancheng, Jiangsu Province. At a total nitrogen dose of 225 kg· hm~(-2), split nitrogen application effects were studied on post-anthesis photosynthesis rate, chlorophyll content, dry matter accumulation and redistribution and grain yield. The penult leaf photosynthetic rate and LAI generally increased with increasing ratio of basal to topdressed nitrogen, and reached the maximum values at the ratio of 7:3, and then decreased. The same responses of yield and amount of post-anthesis accumulated dry matter transferred to grain to ratio of basal to topdressed nitrogen were observed. Further, a high photosynthetic rate benefited the accumulation and redistribution of dry matter aftert-anthesis, which contributed to a high grain yield under an appropriate ratio of basal to topdressed nitrogen.