氮肥运筹对抛秧栽培晚稻物质积累及产量的影响

在总施氮(纯氮)量为180kg/hm2的条件下,研究不同施氮时期对秀水79物质积累和分配及与产量形成的影响。结果表明:最高分蘖数随前期施氮比例的减小呈下降的趋势,氮肥后移有利于成穗率的提高,延长生育期。产量侧重后期施氮处理的产量较生育后期不施氮处理的产量明显提高,按基肥、分蘖肥、穗肥之比为5:3:2施氮方式产量最高,比对照增稻谷3800.0kg/hm2,增产85.15%。氮素的生产力随着基肥施用量的增加有下降趋势。在不同施氮比例下,对有效穗和结实率有显著的影响,而对穗实粒数和千粒重差异不大,因而适当氮肥后移在保证颖花数的前提下,延长剑叶生长时间,防止叶片早衰,可以提高结实率和千粒重而增加产量。

Effect of Nitrogen Management on Matter Production and Yield of Late Rice Cultivated by Seeding-broadcast

Rice matter production, distribution and yield of Xiushui79 were investigated by applying nitrogen at different growth stages with fertilizing 180 kg pure nitrogen per hectare during whole growth duration. The results as follows: The highest tillering number decreased with the decreasing proportion of applying nitrogen at earlier stage. Applying nitrogen at later stage could enhance the panicle formation rate and extend the developmental phase. Moreover, the yield with later nitrogen application was increased significantly compared with that of non- nitrogen. When nitrogen application with the ratio of basal fertilizer, tiller fertilizer, panicle fertilizer was 5:3:2, the yield amounted to maximum and it could increase by 3800.0kg/hm2 (that was 85.15%) than comparison. Nitrogen productivity decreased with the increasing basal fertilizer. Different proportion of applying nitrogen could effect considerably on the effective panicle number and the setting percentage, but had no significant effect on the number of filled grain and the thousand-grain weight. Therefore, maintaining sufficient spikelet number, appropriate later nitrogen application could extend the growth stage of flag leaves, prevent premature senescence and increase yield by enhancing setting percentage and thousand-grain weight.