Zhao Ben, Ata-Ul-Karim Syed Tahir, Duan Aiwang, Gao Yang, Lou He, Liu Zugui, Qin Anzhen, Ning Dongfeng, Ma Shoutian, Liu Zhandong
Key Laboratory of Crop Water Use and Regulation, Ministry of Agriculture, Farmland Irrigation Research Institute, Chinese Academy of Agricultural Sciences, Xinxiang, China.
Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan.
Front Plant Sci. 2022 Apr 8;13:864258. doi: 10.3389/fpls.2022.864258. eCollection 2022.
Accurate and timely appraisal of plant nitrogen (N) demand is imperative to regulate the canopy structure and corn production. The strength and time of plant N deficit can be quantified by critical N concentration. The study was aimed to analyze nitrogen nutrition index (NNI), nitrogen deficit content (NDC), plant nitrogen productivity (PNP), and a fraction of intercepted photosynthetic active radiation (FIPAR) across different N treatments and to develop NNI-NDC, NNI-PNP, NNI-FIPAR, NDC-PNP, and NDC-FIPAR relationships from V6 to V12 stages of corn to quantify the suitable PNP and FIPAR values under the optimal plant N condition. Four multi-N rates (0, 75, 90, 150, 180, 225, 270, and 300 kg N ha) field experiments were conducted with two cultivars of corn in Henan province of China. Results indicated that N fertilization affected yield, plant biomass, plant N content, and leaf area index. The values of NNI and NDC were from 0.54 to 1.28 kg ha and from -28.13 to 21.99 kg ha under the different treatments of N rate, respectively. The NDC and NNI showed significantly negative relationships from V6 to V12 stages. The values of PNP and FIPAR increased gradually with the crop growth process. The PNP values gradually declined while the FIPAR values of every leaf layer increased with the increase of N supply. The NDC-PNP and NNI-FIPAR relationships were significantly positive; however, the relationships between NNI-PNP and NDC-FIPAR were significantly negative during the vegetative period of corn. The coefficient of determination ( ) based on NNI was better than that on NDC. The FIPAR values were ~0.35, 0.67, and 0.76% at the upper, middle, and bottom of leaf layers, respectively, and PNP values were ~39, 44, and 51 kg kg at V6, V9, and V12 stages, respectively, when NNI and NDC values were equal to 1 and 0 kg ha, respectively. This study described the quantitative information about the effect of a plant's internal N deficit on plant N productivity and canopy light intercept. The projected results would assist in predicting the appropriate plant growth status during key N top-dressing stages of corn, which can optimize N application and improve N use efficiency.
准确及时地评估植物氮素需求对于调控冠层结构和玉米产量至关重要。植物氮素亏缺的强度和时间可以通过临界氮浓度来量化。本研究旨在分析不同施氮处理下的氮素营养指数（NNI）、氮素亏缺含量（NDC）、植物氮素生产力（PNP）以及光合有效辐射截获率（FIPAR），并建立玉米从V6到V12阶段的NNI - NDC、NNI - PNP、NNI - FIPAR、NDC - PNP和NDC - FIPAR关系，以量化最佳植物氮素条件下合适的PNP和FIPAR值。在中国河南省对两个玉米品种进行了四个多施氮量（0、75、90、150、180、225、270和300 kg N·ha⁻¹）的田间试验。结果表明，施氮量影响产量、植物生物量、植物氮含量和叶面积指数。在不同施氮量处理下，NNI值为0.54至1.28 kg·ha⁻¹，NDC值为 - 28.13至21.99 kg·ha⁻¹。从V6到V12阶段，NDC和NNI呈显著负相关。PNP和FIPAR值随作物生长过程逐渐增加。随着施氮量增加，PNP值逐渐下降，而各叶层的FIPAR值增加。在玉米营养生长期，NDC - PNP和NNI - FIPAR关系呈显著正相关；然而，NNI - PNP和NDC - FIPAR之间的关系呈显著负相关。基于NNI的决定系数（ ）优于基于NDC的决定系数。当NNI和NDC值分别等于1和0 kg·ha⁻¹时，在V6、V9和V12阶段，叶层上部、中部和底部的FIPAR值分别约为0.35%、0.67%和0.76%，PNP值分别约为39、44和51 kg·kg⁻¹。本研究描述了植物内部氮素亏缺对植物氮素生产力和冠层光截获影响的定量信息。预测结果将有助于预测玉米关键追氮阶段的适宜植物生长状况，从而优化氮肥施用并提高氮素利用效率。
