Biological nitrogen fixation (BNF) in legume crops is a crucial ecosystem service that enhances soil nitrogen and reduces the need for chemical fertilisers. This study evaluates the factors influencing the proportion of plant nitrogen derived from atmospheric fixation (Ndfa) in legume crops. We compiled a global dataset spanning from 1980 to 2018 and used the 15N method to assess the impacts of crop species, climatic conditions, stand composition and nitrogen fertilisation on Ndfa. The global meta‐analysis reveals that the percentage of nitrogen derived from atmospheric fixation (Ndfa) in legumes ranges from 5% to 99%, with an average of 68%. Fodder legumes exhibited higher Ndfa, averaging 75%, while grain legumes showed more variability, ranging from 38% to 85%, depending on species and climatic conditions. The significant variability in Ndfa underscores the complexity of the process, which is influenced by species‐specific traits, ecological conditions and competition in mixed stands. However, the current data is insufficient for precise Ndfa estimation in nitrogen balances and decision support tools. The study highlights the need for further research on the impact of nitrogen fertilisation and stand composition on Ndfa. These findings emphasise the potential of BNF to support sustainable agriculture by improving nitrogen availability and reducing dependence on synthetic fertilisers and particularly susceptibility to climate change challenges. To optimise the benefits of BNF, future research should focus on refining fertilisation regimes and exploring species‐specific responses to various ecological conditions. Exploring adaptive strategies, like selecting drought‐tolerant legumes and optimising irrigation, is essential. This will enhance the application of BNF in diverse agricultural systems, contributing to more sustainable and efficient farming practices.

中文翻译：

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气候变化下生物固氮促进农业可持续发展——荟萃分析的新见解


豆科作物的生物固氮（BNF）是一项重要的生态系统服务，可以提高土壤氮并减少对化肥的需求。本研究评估了影响豆科作物中来自大气固定（Ndfa）的植物氮比例的因素。我们编制了 1980 年至 2018 年的全球数据集，并使用 15N 方法评估了作物种类、气候条件、林分组成和氮肥对 Ndfa 的影响。全球荟萃分析显示，豆类中来自大气固定（Ndfa）的氮的百分比范围为 5% 至 99%，平均为 68%。饲料豆类表现出较高的 Ndfa，平均为 75%，而谷物豆类表现出更大的变异性，范围从 38% 到 85%，具体取决于物种和气候条件。 Ndfa 的显着变异凸显了该过程的复杂性，该过程受到物种特定性状、生态条件和混合林分竞争的影响。然而，目前的数据不足以准确估算氮平衡和决策支持工具中的 Ndfa。该研究强调需要进一步研究氮肥和林分组成对 Ndfa 的影响。这些发现强调了 BNF 通过提高氮肥利用率和减少对合成肥料的依赖，特别是对气候变化挑战的敏感性来支持可持续农业的潜力。为了优化 BNF 的效益，未来的研究应侧重于完善施肥方案并探索物种对各种生态条件的特异性反应。探索适应性策略，例如选择耐旱豆类和优化灌溉，至关重要。 这将增强 BNF 在不同农业系统中的应用，有助于实现更可持续、更高效的农业实践。