Journal of Integrative Agriculture ›› 2025, Vol. 24 ›› Issue (2): 724-738.DOI: 10.1016/j.jia.2024.08.027

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在控水条件下水分亏缺影响冬小麦的氮营养指数

  

  • 收稿日期:2024-02-23 接受日期:2024-07-29 出版日期:2025-02-20 发布日期:2025-01-22

Water deficit affects the nitrogen nutrition index of winter wheat under controlled water conditions

Ben Zhao1,2, Anzhen Qin2, Wei Feng3, Xinqiang Qiu4, Pingyan Wang4, Haixia Qin4, Yang Gao2, Guojie Wang5, Zhandong Liu2#, Ata-Ul-Karim Syed Tahir5#   

  1. 1 College of Tobacco Science, Henan Agricultural University, Zhengzhou 450002, China

    2 Key Laboratory of Crop Water Use and Regulation, Ministry of Agriculture and Rural Affairs/Farmland Irrigation Research Institute, Chinese Academy of Agricultural Sciences, Xinxiang 453003, China

    3 National Engineering Research Center for Wheat/State Key Laboratory of Wheat and Maize Crop Science, Henan Agricultural University, Zhengzhou 450002, China

    4 Henan Provincial Water Conservancy Research Institute/Center of Efficient Irrigation Engineering and Technology Research of Henan Province, Zhengzhou 450002, China

    5 Department of Plant Science, The Pennsylvania State University, State College, PA 16802, USA

  • Received:2024-02-23 Accepted:2024-07-29 Online:2025-02-20 Published:2025-01-22
  • About author:Ben Zhao, E-mail: zhaoben517@163.com; #Correspondence Zhandong Liu, E-mail: liuzhaodong@caas.cn; Syed Tahir Ata-Ul-Karim, E-mail: ataulkarim@agro.au.dk
  • Supported by:
    This study was supported by the National Natural Science Foundation of China (51609247), the Henan Provincial Natural Science Foundation, China (222300420589, 202300410553), the Central Public-interest Scientific Institution Basal Research Fund, China (FIRI2022-22), the Science & Technology Fundamental Resources Investigation Program, China (2022FY101601), the Science and Technology Project of Xinxiang City, Henan Province, China (GG2021024), the Major Special Science and Technology Project of Henan Province, China (221100110700), and the Joint Fund of Science and Technology Research and Development Plan of Henan Province, China (Superior Discipline Cultivation) (222301420104).

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摘要：

氮素的吸收受水分供应的调节，水分不足会通过减少氮素的吸收和利用来限制作物对氮素的反应。水分供应对作物氮素的反应具有复杂多样性，使得预测和量化水分不足对作物氮素状况的影响变得困难。氮营养指数（NNI）已被广泛用于准确诊断作物氮素状况并评估氮肥施用的有效性。在水分限制条件下，已经发现NNI下降的现象。然而，导致这种下降的潜在原因尚未被发现。本研究旨在阐明在水分限制条件下冬小麦NNI下降的原因，并给出如何在不同水氮互作处理下准确利用NNI 诊断冬小麦氮素状况的方法。本研究是在2018至2021年遮雨棚条件下进行，设有不同的水氮耦合处理，其中氮肥设置75 和 225 kg N ha-1 2个梯度，灌溉设置120 至 510 mm 4个梯度（W0~W3）。在冬小麦拔节期、孕穗期、开花期和灌浆期记录植株氮积累量、地上部生物量（SB）、植株氮浓度（%N）、土壤硝态氮含量、实际蒸散量（ETa）和产量。与W0处理相比，W1至W3处理在2018-2021年的冬小麦拔节期、孕穗期、开花期和灌浆期的NNI值分别增加了10.2~20.5%、12.6~24.8%、14~24.8%和16.8~24.8%。在水分限制条件下，NNI下降主要源于两个原因。首先，冬小麦ETa和SB的降低导致水分限制条件下临界氮浓度（%Nc）增加，这是高氮条件下NNI的下降的主要原因。其次，在低氮条件下，冬小麦植株%N的变化起到了更显著的作用。在水分限制条件下，冬小麦植株氮素积累与SB呈显著正相关，与土壤硝态氮含量呈显著负相关，这表明植株氮素积累是由冬小麦SB和土壤硝态氮含量共同调节决定的。然而，这种调节也受水分供应的影响，土壤水分供应的增加促进了更多土壤硝态氮被冬小麦植株所吸收，导致冬小麦植物氮素积累与ETa之间在不同水氮互作处理下呈显著正相关。因此，在评估水分限制条件下土壤氮素供应时，应考虑土壤水分供应状况的影响。这些发现为不同水氮互作处理下冬小麦NNI下降的原因给与了深入的分析，并有助于更准确地利用NNI评估冬小麦的氮素状况。

Abstract:

Nitrogen (N) uptake is regulated by water availability, and a water deficit can limit crop N responses by reducing N uptake and utilization.  The complex and multifaceted interplay between water availability and the crop N response makes it difficult to predict and quantify the effect of water deficit on crop N status.  The nitrogen nutrition index (NNI) has been widely used to accurately diagnose crop N status and to evaluate the effectiveness of N application.  The decline of NNI under water-limiting conditions has been documented, although the underlying mechanism governing this decline is not fully understood.  This study aimed to elucidate the reason for the decline of NNI under water-limiting conditions and to provide insights into the accurate utilization of NNI for assessing crop N status under different water–N interaction treatments.  Rainout shelter experiments were conducted over three growing seasons from 2018 to 2021 under different N (75 and 225 kg N ha–1, low N and high N) and water (120 to 510 mm, W0 to W3) co-limitation treatments.  Plant N accumulation, shoot biomass (SB), plant N concentration (%N), soil nitrate-N content, actual evapotranspiration (ETa), and yield were recorded at the stem elongation, booting, anthesis and grain filling stages.  Compared to W0, W1 to W3 treatments exhibited NNI values that were greater by 10.2 to 20.5%, 12.6 to 24.8%, 14 to 24.8%, and 16.8 to 24.8% at stem elongation, booting, anthesis, and grain filling, respectively, across the 2018–2021 seasons.  This decline in NNI under water-limiting conditions stemmed from two main factors.  First, reduced ETa and SB led to a greater critical N concentration (%Nc) under water-limiting conditions, which contributed to the decline in NNI primarily under high N conditions.  Second, changes in plant %N played a more significant role under low N conditions.  Plant N accumulation exhibited a positive allometric relationship with SB and a negative relationship with soil nitrate-N content under water-limiting conditions, indicating co-regulation by SB and the soil nitrate-N content.  However, this regulation was influenced by water availability.  Plant N accumulation sourced from the soil nitrate-N content reflects soil N availability.  Greater soil water availability facilitated greater absorption of soil nitrate-N into the plants, leading to a positive correlation between plant N accumulation and ETa across the different water–N interaction treatments.  Therefore, considering the impact of soil water availability is crucial when assessing soil N availability under water-limiting conditions.  The findings of this study provide valuable insights into the factors contributing to the decline in NNI among different water–N interaction treatments and can contribute to the more accurate utilization of NNI for assessing winter wheat N status.


Key words: critical nitrogen concentration , shoot biomass ,  plant nitrogen accumulation ,  soil nitrate N concentration ,  soil water content