【摘要】 对协优64水稻进行的再生两熟盆栽试验表明,头季稻吸氮高峰出现在栽秧至分蘖及再生芽萌生阶段,其平均吸氮速率与再生稻相似。水稻再生两熟栽培,头季稻所吸收的氮量达两季稻吸氮总量的70%以上,而再生稻对头季稻茬中氮素的再利用率达31.0—41.5%。再生稻的稻谷重约为头季稻的70%,且经济系数大大高于头季稻,因此,水稻再生两熟是有利于物质和能量转化的栽培方式。更多还原

【Abstract】 The effect of nitrogen fertilizer on growth of ratooning double-crop rice and absorption or utilization of nitrogen by two rices were investigated by pot experiments using urea. Results showed that:1, There were similarities in the mean rate of N absorption for both first rice and ratooning rice. The peak of N absorption appeared in trasplanting-tillering stage of first rice and ratooning stage after heading stage, respectively. The amount of N absorption by first rice was over 70% of the total amount absorbed by the 2 rices, but, reuse ratio of nitrogen in the stubble of first rice in ratooning rice growing period was 31.0—41.5%.2, Recoverage of applied N by rice was much higher than that of double cropping rice, however, the N lost and retained in soil were lower than that of double cropping rice in ratooning double-crop system of rice.3, The grain weight of ratooning rice was about 70% of that of first rice, and the economic coefficient was much higher than that of first rice, which shows ratooning double-crop system were advantageous to the tranformation of energy and matter.4, The highest grain weight was obtained while application of N fertilizer as basal dressing and accelarating ratoon dressing, under these conditions the economic coeffficient and grain-producing power of nitrogen also were the largest.5, The level of N applied on first rice had considerable influence to grain weight of first rice, however, there was no significant difference to that of ratooning rice.更多还原