Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters (CIC-FEMD), Nanjing University of Information Science and Technology, Nanjing 210044, Jiangsu, China; Key Laboratory of Ecosystem Carbon Source and Sink, China Meteorological Administration (ECSS-CMA), Nanjing University of Information Science and Technology, Nanjing 210044, Jiangsu, China.
State Key Laboratory of Earth Surface Processes and Resource Ecology, Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China; School of Natural Resources, Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China.
Sci Total Environ. 2024 Apr 10;920:171030. doi: 10.1016/j.scitotenv.2024.171030. Epub 2024 Feb 16.
Increased surface ozone (O) pollution seriously threatens crop production, and ethylenediurea (EDU) can alleviate crop yield reduction caused by O. However, the reason for the decrease in grain nitrogen (N) accumulation caused by O and whether EDU serves as N fertilizer remain unclear. An experiment was conducted to investigate the impacts of factorial combinations of O enrichment (ambient air plus 60 ppb) and EDU (foliage spray with 450 ppm solutions) on N concentration, accumulation and remobilization in hybrid rice seedlings. Compared to ambient condition, elevated O significantly inhibited the N accumulation in vegetative organs during anthesis and grain N accumulation during the maturity stage. Elevated O significantly decreased the total N accumulation during anthesis and maturity stages, with a greater impact at the latter stage. The decrease in grain N accumulation caused by O was attributed to a decrease in N remobilization of vegetative organs during the grain filling period as well as to a decrease in post-anthesis N uptake. However, there was no significant change in the proportion of N remobilization and N uptake in grain N accumulation. The inhibitory effect of O on N remobilization in the upper canopy leaves was greater than that in the lower canopy leaves. In addition, elevated O increased the N accumulation of panicles at the anthesis stage, mainly by resulting in earlier heading of rice. EDU only increased N accumulation at the maturity stage, which was mainly attributed to an increase in rice biomass by EDU. EDU had no significant effect on N concentration, N remobilization process, and N harvest index. The findings are helpful to better understand the utilization of N fertilizer by rice under O pollution, and can also provide a theoretical basis for sustainable nutrient management to alleviate the negative impact of O on crop yield and quality.
大气臭氧（O）污染加剧严重威胁作物生产，而乙二脲（EDU）可以缓解 O 导致的作物减产。然而，O 导致籽粒氮（N）积累减少的原因以及 EDU 是否作为 N 肥尚不清楚。本试验通过臭氧（O）浓度（大气臭氧+60 ppb）和乙二脲（叶片喷施 450 ppm 溶液）的因子组合处理，研究了其对杂交水稻幼苗 N 浓度、积累和再利用的影响。与对照相比，O 浓度升高显著抑制了抽穗期营养器官的 N 积累和成熟期籽粒的 N 积累。O 浓度升高显著降低了抽穗期和成熟期的总 N 积累，后者的影响更大。O 导致的籽粒 N 积累减少归因于灌浆期营养器官的 N 再利用减少和抽穗后 N 吸收减少。然而，籽粒 N 积累中 N 再利用和 N 吸收的比例没有显著变化。O 对上层冠层叶片 N 再利用的抑制作用大于对下层冠层叶片的抑制作用。此外，O 浓度升高增加了抽穗期穗部的 N 积累，主要是由于水稻提前抽穗。EDU 仅在成熟期增加了 N 积累，这主要归因于 EDU 增加了水稻生物量。EDU 对 N 浓度、N 再利用过程和 N 收获指数没有显著影响。这些发现有助于更好地理解在 O 污染下水稻对 N 肥的利用，也为可持续养分管理提供了理论依据，以减轻 O 对作物产量和品质的负面影响。
