不同施氮量对超高产小麦灌浆期光合日变化的影响

试验研究了不同施氮量对超高产小麦灌浆期光合日变化的影响。结果表明,超高产麦田光合特性日变化是由气孔因素和非气孔因素共同作用的结果,随施氮量增加,小麦的光合特性逐渐增强,光合"午休"现象有一定程度的减缓。但过多的施氮量(纯氮375 kg/hm2)虽然有较高的光合速率,但是降低了群体叶面积指数,千粒重下降,产量降低。由此表明,氮肥对超高产小麦光合日变化有较大的调节作用,但光合作用与产量并非均呈正相关关系。

Effects of Different Nitrogen Content on Diurual Variation of Photosynthesis in Super-high-yield Wheat at Filling Stage

The diurual variation of photosynthesis were studied in super-high-yield wheat under different nitrogen amounts.The results showed that both stomata limitation and non-stomata limitations resulted in the diurual variation of the characteristics of photosynthesis in winter wheat.As the amount of nitrogen application increased,the characteristics of photosynthesis were gradually reinforced and the midday depression of photosynthesis released in some degree.Although the photosynthetic rates were reinforced by excessive nitrogen content(pure nitrogen 375 kg/hm2),the leaf area index of colony,1 000-grain weight and the yields decreased.So,it showed that nitrogen fertilizer could regulate the diurual variation of photosynthesis in some degree,but the photosynthesis was not positively related to the wheat yield.