氮肥用量与运筹方式对晚籼稻产量及花后干物质积累与转运的影响

旨在建立晚籼稻合理氮肥施用技术,探究了氮肥用量与运筹方式对晚籼稻产量及干物质积累与转运的影响。以‘益9优447’和‘益9优651’为试验材料,设置2个氮肥用量和3种氮肥运筹方式,并以不施氮处理为对照,测定产量及其构成因素、干物质积累量和剑叶SPAD值等指标。与不施氮处理相比,施氮可增加晚籼稻有效穗数12.3%~61.9%,降低花后剑叶SPAD值衰减率5.9~8.5个百分点,增大花后干物质转运量0.8~1.1倍,提高花后干物质转运率5.5~10.2个百分点和增加产量23.5%~35.6%。氮肥运筹方式对晚籼稻产量及干物质积累与转运的影响较小。氮肥用量270 kg/hm²与运筹方式基肥:分蘖肥:穗肥:粒肥=40%:20%:25%:15%组合处理的产量及干物质转运量与转运率最高。氮肥用量180 kg/hm²与氮肥运筹方式基肥:分蘖肥:穗肥=60%:20%:20%组合处理的氮肥农学利用率最高。氮肥用量为180 kg/hm²时,应增加氮肥基肥使用比例;氮肥用量为270 kg/hm²时,可适当增加氮肥后期追肥次数和比例。

Nitrogen Application Rate and Mode: Effects on Yield and Dry Matter Accumulation and Transport After Flowering of Late Indica Rice

In order to establish suitable nitrogen application technology for late indica rice, we investigated the effects of nitrogen application rate and mode on the yield and dry matter accumulation and transport of late indica rice. Two late indica rice varieties, ‘Yi 9 You 447’ and ‘Yi 9 You 651’, were used as the materials. Two nitrogen application rates and three nitrogen application modes were set up, and no nitrogen application treatment was used as control. The yield and its components, dry matter accumulation and flag leaf SPAD value were determined. Compared with no nitrogen application, the effective panicle number and yield of late indica rice was increased by 12.3%-61.9% and 23.5%-35.6% by nitrogen application, respectively. After flowering, the flag leaf SPAD value attenuation rate was decreased by 5.9-8.5 percentage points, dry matter transport volume was increased by 0.8-1.1 times, and dry matter transport rate was increased by 5.5-10.2 percentage points under nitrogen application, compared with those under no nitrogen application. Nitrogen application modes had little effect on the yield and dry matter accumulation and transport after flowering of late indica rice. The highest yield and dry matter accumulation and transport rate were achieved in the combination of nitrogen rate of 270 kg/hm ² and the application mode of basal, tillering, panicle and grain fertilizer in the ratio of 40%:20%:25%:15%. The highest nitrogen agronomic efficiency was observed in nitrogen rate of 180 kg/hm² and the application mode of basal, tillering and panicle fertilizer in the ratio of 60%:20%:20%. When nitrogen rate was 180 kg/hm², the ratio of nitrogen basal fertilizer should be increased. When nitrogen rate was 270 kg/hm², the ratio and times of topdressing should be appropriately increased.