Kubar Muhammad Saleem, Wang Chao, Noor Rana Shahzad, Feng Meichen, Yang Wude, Kubar Kashif Ali, Soomro Khalilullah, Yang Chen, Sun Hui, Mohamed Hasan, Mosa Walid F A
College of Agriculture, Shanxi Agricultural University, Taigu Jinzhong, China.
Department of Agriculture, Biological, Environment and Energy Engineering, College of Engineering, Northeast Agricultural University, Harbin, China.
Front Plant Sci. 2022 Nov 15;13:1011515. doi: 10.3389/fpls.2022.1011515. eCollection 2022.
Improper optimization of the rates and ratios of nitrogen application reduces grain yields and increases the nitrogen loss, thereby affecting environmental quality. In addition, scarcer evidence exists on the integrative approach of nitrogen, which could have effects on the biochemical and physiological characteristics of wheat. Treatments were arranged as nitrogen (N) rates of 00, 75, 150, 225, and 300 kg ha in the main plots, and different nitrogen ratios were organized in subplots at 5:5:0:0 and 6:4:0:0, which were applied at the sowing, jointing, flowering, and grain filling stages. The results revealed that 225 kg N ha significantly enhanced the stomatal conductance ( ), photosynthetic rate ( ), intercellular CO ( ), transpiration rate ( ), and total chlorophyll by 28.5%, 42.3%, 10.0%, 15.2%, and 50%, receptively, at the jointing stage in comparison to the control (0 kg N ha). Nitrogen application of 225 kg ha increased the soil-plant analysis development (SPAD) value and the chlorophyll a, chlorophyll b, and carotenoid contents of winter wheat under the 6:4:0:0 ratio. The trend of the photosynthetic characteristics was observed to be greater at the 6:4:0:0 fertilization ratio compared to that at 5:5:0:0. The photosynthetic rate was significantly associated with the biochemical and physiological characteristics of winter wheat. In conclusion, the nitrogen dose of 225 kg ha and the ratio of 6:4:0:0 (quantity applied at the sowing, jointing, flowering, and grain filling stages) effectively promoted the photosynthetic and other physiological characteristics of winter wheat.
氮肥施用量和比例优化不当会降低粮食产量并增加氮素损失，从而影响环境质量。此外，关于氮素综合施用方法的证据较少，而这种方法可能会对小麦的生化和生理特性产生影响。试验设置为主区施氮量分别为0、75、150、225和300 kg/ha，副区设置不同氮素比例5:5:0:0和6:4:0:0，并在播种期、拔节期、开花期和灌浆期施用。结果表明，与对照（0 kg/ha）相比，225 kg/ha的施氮量在拔节期显著提高了气孔导度、光合速率、胞间CO₂浓度、蒸腾速率和总叶绿素含量，分别提高了28.5%、42.3%、10.0%、15.2%和50%。在6:4:0:0比例下，225 kg/ha的施氮量提高了冬小麦的土壤-植物营养状况诊断（SPAD）值以及叶绿素a、叶绿素b和类胡萝卜素含量。与5:5:0:0施肥比例相比，6:4:0:0施肥比例下光合特性的变化趋势更为明显。光合速率与冬小麦的生化和生理特性显著相关。总之，225 kg/ha的施氮量和6:4:0:0的比例（在播种期、拔节期、开花期和灌浆期施用）有效地促进了冬小麦的光合及其他生理特性。
