不同氮肥施用量对再生稻干物质积累运转的影响

Effects of nitrogen fertilizer rates on dry matter accumulation and transportation in ratoon rice

探讨不同氮肥施用量对再生稻干物质积累运转的影响。结果表明,适量的促芽促苗氮肥,可显著增强头季稻的光合生产能力,促进干物质在叶片、茎鞘的积累,成熟收割时有较大份额的干物质残留于稻桩;增加再生分蘖成穗数和单蘖叶面积,从而显著增强再生稻的光合生产量;增加稻桩、叶片干物质的转运量。因此,显著增加了再生分蘖的干物质积累量。再生稻齐穗至成熟期的干物质净积累量、再生稻的库容量及稻谷产量均与促芽促苗氮肥施用量呈抛物线型相关,获得最高产量的施氮量为241.3 kg·hm-2。

Effects of nitrogen fertilizer rates on dry matter accumulation and transportation in ratoon rice were studied. The results showed that the photo-production was significantly enhanced in main rice exposed to optimum nitrogen application rate used to promote bud and tiller, dry matter accumulation in leaves and stem-sheath increased, the stubble of main rice remained the larger share in the dry matter after harvesting, contributed to the increase of productive tillers and leaf areas, so photosynthetic products of ratoon rice increased. It was also found that the optimum nitrogen application had very important role in increasing transported rate of dry matter from the stubble and leaves of main rice, leading to significantly increase of the dry matter accumulation in ratoon rice. In the period from full heading to ripening of ratoon crop, the net accumulation of dry matter, panicle number and grain yield were parabolically related to the nitrogen application rate used to promote bud and tiller. The grain yield of ratoon crop exposed to 241. 3 kg·hm-2 was the highest.