Rice alternated with upland crops has become increasingly popular in recent years. To investigate the residual effects of nitrogen from the previous upland crop on rice growth, two cropping systems, garlic-rice and wheat-rice, were studied from 2014 to 2017 under field conditions and from 2016 to 2017 under pot conditions. The results showed that the total nitrogen content in the 0–0.2 m soil was higher for the garlic-rice cropping system than for the wheat-rice cropping system and the ¹⁵N isotope abundance of the soil after harvesting garlic was 63% higher than that after harvesting wheat. Residual nitrogen from the preceding crops was one of the main nitrogen sources for rice growth. The contribution of residual nitrogen accounted for 17% to 60% of the total nitrogen accumulation by rice plants during the vegetative stage, which gradually decreased after the rice jointing stage. Most of the residual nitrogen absorbed by rice plants was transported to the reproductive organs for grain growth. Therefore, the growth of vegetative organs, viz., tillers and leaves, was more vigorous under the garlic-rice cropping system than under the wheat-rice cropping system. This led to a significant increase in total nitrogen accumulation in rice plants and an increase in rice yield by 8% to 16%, even under identical management of rice under upland crop–paddy rice systems. Thus, under upland crop–paddy rice systems, high-yield and high-efficiency rice production can be achieved by utilizing residual nitrogen from the preceding crops and decreasing the application of base and tiller nitrogen.

近年来，水稻与旱作交替出现已变得越来越流行。为了研究先前陆地作物氮素对水稻生长的残留影响，研究了2014年至2017年在田间条件下以及2016年至2017年在盆栽条件下的两种种植系统，大蒜-水稻和小麦-水稻。结果表明，大蒜-水稻种植系统在0-0.2 m土壤中的总氮含量高于小麦-水稻种植系统和¹⁵大蒜收获后土壤的N同位素丰度比小麦收获后高63％。前茬作物的残留氮是水稻生长的主要氮源之一。在营养生长阶段，残留氮的贡献占水稻植物总氮积累的17％至60％，在水稻拔节后逐渐减少。水稻植物吸收的大部分残留氮被转运到生殖器官以进行谷物生长。因此，在大蒜-水稻种植体系下，营养器官的生长，即分leaves和叶片比在小麦-水稻种植体系下的生长更为活跃。这导致水稻植株中总氮的积累显着增加，水稻产量增加了8％至16％，即使在旱作水稻系统下，在相同的水稻管理下也是如此。因此，在旱作水稻系统下，通过利用前茬作物的残留氮并减少基础氮和分till氮的使用，可以实现高产高效水稻。