Rice ratooning is an ancient technology, known as harvesting twice after one sowing. In recent years, ratoon rice has drawn much attention and been widely practiced by farmers in central China because of its advantages in saving labor and increasing profit. For ratoon crop (RC), nitrogen (N) application for promoting bud initiation (N_bud) and for promoting regenerated tiller growth (N_tiller) are two common N management practices. However, it is still obscure about their effects on grain yield and quality of RC. Field experiments were conducted to compare the effects of N_bud (75 kg N ha⁻¹ application at 12 days after heading of main crop, MC) and N_tiller (75 kg N ha⁻¹ application at 2 days after harvesting of MC) on the grain yield and quality of RC in 2018 and 2019. Compared to N_bud, N_tiller had an evident and positive effect on grain yield, head rice percentage (HRP) and chalkiness degree (CD) of RC. Averaged across years, N_bud and N_tiller increased grain yield of RC by 5.5 % and 30.5 %, respectively. Moreover, N_tiller improved grain quality with an increase of 10.5 % in HRP and a decrease of 10.2 % in CD. N_tiller significantly increased sink size like spikelets m^-2, and source ability including leaf area index, leaf N content, and crop growth rate in ratoon crop. The positive effect of N_bud on grain yield of RC was positively correlated with the increase in panicles m^-2, but negatively correlated with the panicles m^-2 of MC. N_bud has no effect on stubble dry weight, and significantly increased stubble N concentration, but significantly decreased stubble non-structural carbohydrate concentration at maturity in the main season. Overall, our results indicated that nutrient status of straw and panicle number in MC affected the roles of N_bud on RC yield, and more attention should be paid on N_tiller in future RC production.

水稻再生是一项古老的技术，称为一次播种两次收获。近年来，再生稻由于具有省工、增利等优点，受到广大中部地区农民的广泛关注和广泛推广。对于宿根作物 (RC)，施氮 (N) 以促进芽萌生 (N _bud ) 和促进再生分蘖生长 (N_分蘖) 是两种常见的氮管理实践。然而，它们对RC谷物产量和品质的影响仍不清楚。进行田间试验以比较氮_芽（在主要作物 MC 抽穗后 12 天施用75 kg N ha ^-1）和 N_分蘖（75 kg N ha ^-1应用在上相较于N的2018和2019年的产量和品质的RC MC的收获后2天）_芽，N_分蘖对产量，头稻百分比（HRP）和垩白度的明显的积极影响（CD ) 的 RC。平均而言，N_芽和 N_分蘖分别使 RC 的谷物产量提高了 5.5% 和 30.5%。此外，N_分蘖提高了谷物质量，HRP 增加了 10.5%，CD 减少了 10.2%。氮_分蘖显着增加了宿根作物的汇量（如小穗m ^-2）和源能力，包括叶面积指数、叶氮含量和作物生长率。N_芽的积极作用上RC的籽粒产量呈正圆锥花序增加相关中号^-2，但与圆锥花序中号负相关^-2 MC的。N_芽对留茬干重没有影响，在主季成熟时显着提高了留茬氮浓度，但显着降低了留茬非结构碳水化合物浓度。总体而言，我们的结果表明，秸秆养分状况和 MC 中的穗数会影响 N_芽对 RC 产量的作用，在未来的 RC 生产中应更加关注 N_分蘖。