Southern Regional Collaborative Innovation Center for Grain and Oil Crops (CICGO), Hunan Agricultural University, Changsha, China.
Sci Rep. 2019 Jan 14;9(1):92. doi: 10.1038/s41598-018-36572-0.
Reducing N rate without sacrificing grain yield is crucial for sustainable rice production in China. In this study, field experiments were conducted in 2016 and 2017 to determine whether the response of grain yield to reducing N rate varied between double-season rice (DSR) and single-season rice (SSR). Three N rates were applied for each rice crop, i.e. 150 kg ha (N150, the locally recommended N rate), 90 kg ha (N90), and 0 kg ha (N0). Grain yield was lower under N90 than under N150 in DSR by 11-18%, whereas the difference was not significant in SSR. Grain yield under N0 was 36-63% lower in DSR than in SSR. There was a significant relationship between percentage change in grain yield comparing N90 to N150 with grain yield under N0. Furthermore, it was observed that grain yield under N0 was not significantly associated with growth duration but was closely associated with daily grain yield under N0, and the relationships of daily grain yield under N0 with seasonal average daily mean temperature and solar radiation were not significant. These results indicate that response of grain yield to reducing N rate was more sensitive in DSR compared to SSR due to lower soil N productivity. Growth duration and climatic conditions did not explain the difference in soil N productivity between DSR and SSR. The findings of this study should encourage more research into comparing the inherent traits of plants, especially the morphology and physiology of the root system, between DSR and SSR.
在中国，在不牺牲粮食产量的情况下减少氮肥用量对于可持续水稻生产至关重要。本研究于 2016 年和 2017 年进行了田间试验，以确定减少氮肥用量对双季稻（DSR）和单季稻（SSR）的籽粒产量的响应是否存在差异。每个水稻作物都施用了三种氮素用量，即 150kg·ha（N150，当地推荐的氮素用量）、90kg·ha（N90）和 0kg·ha（N0）。在 DSR 中，N90 处理下的籽粒产量比 N150 处理下低 11-18%，而 SSR 中差异不显著。在 DSR 中，N0 处理下的籽粒产量比 SSR 低 36-63%。N90 与 N150 相比，籽粒产量变化百分比与 N0 下的籽粒产量之间存在显著关系。此外，还观察到 N0 下的籽粒产量与生长时间没有显著关联，但与 N0 下的日籽粒产量密切相关，N0 下的日籽粒产量与季平均日平均温度和太阳辐射之间的关系不显著。这些结果表明，由于土壤氮素生产力较低，与 SSR 相比，DSR 中籽粒产量对氮肥用量减少的响应更为敏感。生长时间和气候条件并不能解释 DSR 和 SSR 之间土壤氮素生产力的差异。本研究的结果应鼓励更多地研究比较双季稻和单季稻之间植物固有特性的差异，特别是根系的形态和生理学特性。
