【摘要】 探讨了不同氮肥施用量对再生稻氮素吸收和分配的影响。结果表明,头季加再生季对促芽促苗氮肥的氮素吸收量与回收率均与促芽促苗氮肥的施用量呈抛物线型相关,吸收量随生育时期的延后而减少;头季稻吸收的促芽促苗氮肥有1/3留存于稻桩,稻桩的氮素积累量也与促芽促苗氮肥施用量呈抛物线型相关,头季收割后即输向再生分蘖,其中以在再生季齐穗前输出最多,对再生分蘖的萌发和生长起了很大的作用,再生季叶片、茎鞘的氮素积累量随促芽促苗氮肥施用量的提高而增加,齐穗以后大量分解转运到穗部,加上稻桩的氮素输出,表观转变率达57％～76％,显示稻桩和营养器官的转化氮是再生季籽粒氮素积累的主要来源;再生季稻谷产量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(N)为241.3 kg·hm-2。更多还原

【Abstract】 The effects of N fertilizer rates on uptake and distribution of N in ratoon rice were .studied. The results showed that the relationship between N uptake and its recovery rate with nitrogen application rates for promoting bud and tiller in main rice and its ratoon crop was a parabola curve. After nitrogen fertilizer was applied, the amount of N uptake decreased with the growing of crops. About 1/3 of N uptake from the nitrogen fertilizer applied to promote bud and tiller was deposited in the main rice stubbie. The total amount of N accumulated in the stubble was closely related to nitrogen application promoting bud and tiller, the relationship exhibited a parabola curve. The nitrogen source in the stubble of main rice was gradually transported to the tillers of ratoon crop after main rice was harvested,it played a great role in bud sprouting and tiller growing. N accumulation in the leaves and stem-sheath of ratoon rice increased with nitrogen application rate enhanced, a large amounts of N in the parts of ratoon rice were transported to the panicles after full heading. The apparent transportation rate was 57% -76% in consideration of N translocation from the stubble of main rice,. This indicated that the nitrogen transported from the stubble and the other parts including leaves and stem-sheath was the main nitrogen source deposited in grains of ratoon rice. The grain yield of ratoon crop had parabola correlation with the nitrogen application rate for promoting bud and tiller. The grain yield of ratoon crop up to 241. 3 kg· hm-2 was the highest.更多还原