美国俄勒冈州立大学Carla R. Reis Ely团队近日研究了全球陆地固氮及其农业改造。该研究于2025年7月16日发表在《自然》杂志上。

生物固氮（BNF）是支持陆地生产力的最大的新氮(N)自然来源，但全球陆地固氮（BNF）的估计仍然高度不确定。

研究组表明这种不确定性部分是由于采样偏差，因为在自然陆地生态系统中进行的野外BNF测量中，固氮物的普遍程度是其全球平均丰度的17倍。为了纠正这种偏差，研究组通过提高野外BNF测量的尺度，对所有主要生物地球化学固氮生态位的空间显式丰度进行了新的估计。

研究组发现自然生物群系的生物固氮量[65（52-77）万亿克氮/年]低于既往经验性自下而上估算值，且主要集中于热带森林与旱地生态系统。同时测得农田与栽培牧场的农业生物固氮量高达56（54-58）万亿克氮/年。较前工业化水平，农业生物固氮已使陆地生物固氮总量提升64%，全陆地氮输入总量增加60%。这些结果表明：生物固氮对自然陆地生物群系碳汇的限制作用强于预期；其农业氮源贡献量高于全球氮循环分析中的常规认知。这对建立氮使用的安全操作限值具有重要启示。

附：英文原文

Title: Global terrestrial nitrogen fixation and its modification by agriculture

Author: Reis Ely, Carla R., Perakis, Steven S., Cleveland, Cory C., Menge, Duncan N. L., Reed, Sasha C., Taylor, Benton N., Batterman, Sarah A., Clark, Christopher M., Crews, Timothy E., Dynarski, Katherine A., Gei, Maga, Gundale, Michael J., Herridge, David F., Jovan, Sarah E., Kou-Giesbrecht, Sian, Peoples, Mark B., Piipponen, Johannes, Rodrguez-Caballero, Emilio, Salmon, Verity G., Soper, Fiona M., Staccone, Anika P., Weber, Bettina, Williams, Christopher A., Wurzburger, Nina

Issue&Volume: 2025-07-16

Abstract: Biological nitrogen fixation (BNF) is the largest natural source of new nitrogen (N) that supports terrestrial productivity1,2, yet estimates of global terrestrial BNF remain highly uncertain3,4. Here we show that this uncertainty is partly because of sampling bias, as field BNF measurements in natural terrestrial ecosystems occur where N fixers are 17 times more prevalent than their mean abundances worldwide. To correct this bias, we develop new estimates of global terrestrial BNF by upscaling field BNF measurements using spatially explicit abundances of all major biogeochemical N-fixing niches. We find that natural biomes sustain lower BNF, 65(52–77)TgNyr1, than previous empirical bottom-up estimates3,4, with most BNF occurring in tropical forests and drylands. We also find high agricultural BNF in croplands and cultivated pastures, 56(54–58)TgNyr1. Agricultural BNF has increased terrestrial BNF by 64% and total terrestrial N inputs from all sources by 60% over pre-industrial levels. Our results indicate that BNF may impose stronger constraints on the carbon sink in natural terrestrial biomes and represent a larger source of agricultural N than is generally considered in analyses of the global N cycle5,6, with implications for proposed safe operating limits for N use7,8.

DOI: 10.1038/s41586-025-09201-w

Source: https://www.nature.com/articles/s41586-025-09201-w

来源：科学网  小柯机器人