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Fertilizer management for global ammonia emission reduction

Abstract

Crop production is a large source of atmospheric ammonia (NH3), which poses risks to air quality, human health and ecosystems1,2,3,4,5. However, estimating global NH3 emissions from croplands is subject to uncertainties because of data limitations, thereby limiting the accurate identification of mitigation options and efficacy4,5. Here we develop a machine learning model for generating crop-specific and spatially explicit NH3 emission factors globally (5-arcmin resolution) based on a compiled dataset of field observations. We show that global NH3 emissions from rice, wheat and maize fields in 2018 were 4.3 ± 1.0 Tg N yr−1, lower than previous estimates that did not fully consider fertilizer management practices6,7,8,9. Furthermore, spatially optimizing fertilizer management, as guided by the machine learning model, has the potential to reduce the NH3 emissions by about 38% (1.6 ± 0.4 Tg N yr−1) without altering total fertilizer nitrogen inputs. Specifically, we estimate potential NH3 emissions reductions of 47% (44–56%) for rice, 27% (24–28%) for maize and 26% (20–28%) for wheat cultivation, respectively. Under future climate change scenarios, we estimate that NH3 emissions could increase by 4.0 ± 2.7% under SSP1–2.6 and 5.5 ± 5.7% under SSP5–8.5 by 2030–2060. However, targeted fertilizer management has the potential to mitigate these increases.

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Fig. 1: EFs conditioned on management practices and importance analysis.
Fig. 2: Global cropland NH3 EFs and emissions at a 5-arcmin resolution in 2018 derived by machine learning.
Fig. 3: Country-level differences for mitigation targets.
Fig. 4: Projected changes in NH3 emissions for 2030–2100 relative to the reference year (2018).

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Data availability

The full dataset and list of references for publications used in our machine learning model (Supplementary Table 3) and the global cropland NH3 EFs and emissions at a 5-arcmin resolution in 2018 generated using machine learning (Fig. 2) are available in the Zenodo repository (https://doi.org/10.5281/zenodo.10302502). Data processing and visualization were conducted using Microsoft Excel and Python. Source data are provided with this paper.

Code availability

The source code and results of this research are available under the GNU General Public License v3.0 at GitHub (https://github.com/Rickon566/Fertilizer-Management-for-Global-Ammonia-Emission-Reduction). The model card is available in the Supplementary Information. The spatial analysis was run in ArcGIS v.10.2.

References

  1. Galloway, J. N. et al. Transformation of the nitrogen cycle: recent trends, questions, and potential solutions. Science 320, 889–892 (2008).

    Article  ADS  CAS  PubMed  Google Scholar 

  2. Höpfner, M. et al. Ammonium nitrate particles formed in upper troposphere from ground ammonia sources during Asian monsoons. Nat. Geosci. 12, 608–612 (2019).

    Article  ADS  Google Scholar 

  3. Liu, L. et al. Exploring global changes in agricultural ammonia emissions and their contribution to nitrogen deposition since 1980. Proc. Natl Acad. Sci. USA 119, e2121998119 (2022).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  4. Bodirsky, B. L. et al. Reactive nitrogen requirements to feed the world in 2050 and potential to mitigate nitrogen pollution. Nat. Commun. 5, 3858 (2014).

    Article  ADS  CAS  PubMed  Google Scholar 

  5. Gu, B. J. et al. Abating ammonia is more cost-effective than nitrogen oxides for mitigating PM2.5 air pollution. Science 374, 758–762 (2021).

    Article  ADS  CAS  PubMed  Google Scholar 

  6. Yang, Y. Y. et al. Improved global agricultural crop- and animal-specific ammonia emissions during 1961–2018. Agr. Ecosy. Environ. 344, 108289 (2023).

    Article  CAS  Google Scholar 

  7. Xu, R. T. et al. Global ammonia emissions from synthetic nitrogen fertilizer applications in agricultural systems: empirical and process-based estimates and uncertainty. Glob. Change Biol. 25, 314–326 (2019).

    Article  ADS  Google Scholar 

  8. Ma, R. Y. et al. Global soil-derived ammonia emissions from agricultural nitrogen fertilizer application: a refinement based on regional and crop-specific emission factors. Glob. Change Biol. 27, 855–867 (2021).

    Article  ADS  CAS  Google Scholar 

  9. Zhan, X. Y. et al. Improved estimates of ammonia emissions from global croplands. Environ. Sci. Technol. 55, 1329–1338 (2021).

    Article  ADS  CAS  PubMed  Google Scholar 

  10. Ferrario, M. et al. EDGAR v.6.1. Global Air Pollutant Emissions. European Commission, Joint Research Centre (JRC) http://data.europa.eu/89h/df521e05-6a3b-461c-965a-b703fb62313e (2022).

  11. Ladha, J. K. et al. Achieving the sustainable development goals in agriculture: the crucial role of nitrogen in cereal-based systems. Adv. Agron. 163, 39–116 (2020).

    Article  Google Scholar 

  12. Fesenfeld, L. P., Schmidt, T. S. & Schrode, A. Climate policy for short- and long-lived pollutants. Nat. Clim. Change 8, 934–936 (2018).

    Article  ADS  Google Scholar 

  13. Schulte-Uebbing, L. F., Beusen, A. H. W., Bouwman, A. F. & de Vries, W. From planetary to regional boundaries for agricultural nitrogen pollution. Nature 610, 507–512 (2022).

    Article  ADS  CAS  PubMed  Google Scholar 

  14. Crippa, M. et al. Gridded emissions of air pollutants for the period 1970-2012 within EDGAR v4.3.2. Earth Syst. Sci. Data 10, 1987–2013 (2018).

    Article  ADS  Google Scholar 

  15. Luo, Z. et al. Estimating global ammonia (NH3) emissions based on IASI observations from 2008 to 2018. Atmos. Chem. Phys. 22, 10375–10388 (2022).

    Article  ADS  CAS  Google Scholar 

  16. Van Damme, M. et al. Industrial and agricultural ammonia point sources exposed. Nature 564, 99–103 (2018).

    Article  ADS  PubMed  Google Scholar 

  17. Aneja, V. P., Schlesinger, W. H., Li, Q., Nahas, A. & Battye, W. H. Characterization of the global sources of atmospheric ammonia from agricultural soils. J. Geophys. Res-Atmos. 125, e2019JD031684 (2020).

    Article  ADS  CAS  Google Scholar 

  18. Ma, R. et al. Mitigation potential of global ammonia emissions and related health impacts in the trade network. Nat. Commun. 12, 6308 (2021).

    Article  ADS  CAS  PubMed  PubMed Central  Google Scholar 

  19. Zhang, C. et al. Using nitrification inhibitors and deep placement to tackle the trade-offs between NH3 and N2O emissions in global croplands. Glob. Change Biol. 28, 4409–4422 (2022).

    Article  ADS  CAS  Google Scholar 

  20. Sha, Z. P. et al. Improved soil-crop system management aids in NH3 emission mitigation in China. Environ. Pollut. 289, 117844 (2021).

    Article  CAS  PubMed  Google Scholar 

  21. Ti, C., Xia, L., Chang, S. X. & Yan, X. Y. Potential for mitigating global agricultural ammonia emission: a meta-analysis. Environ. Pollut. 245, 141–148 (2019).

    Article  CAS  PubMed  Google Scholar 

  22. Gu, B. et al. Cost-effective mitigation of nitrogen pollution from global croplands. Nature 613, 77–84 (2023).

    Article  ADS  CAS  PubMed  PubMed Central  Google Scholar 

  23. Xia, L. L. & Yan, X. Y. How to feed the world while reducing nitrogen pollution. Nature 613, 34–35 (2023).

    Article  ADS  CAS  PubMed  Google Scholar 

  24. Shahzad, A. N., Qureshi, M. K., Wakeel, A. & Misselbrook, T. Crop production in Pakistan and low nitrogen use efficiencies. Nat. Sustain. 2, 1106–1114 (2019).

    Article  Google Scholar 

  25. Zhang, X. et al. Managing nitrogen for sustainable development. Nature 528, 51–59 (2015).

    Article  ADS  CAS  PubMed  Google Scholar 

  26. Xu, P. et al. Role of organic and conservation agriculture in ammonia emissions and crop productivity in China. Environ. Sci. Technol. 56, 2977–2989 (2022).

    Article  ADS  CAS  PubMed  Google Scholar 

  27. Xu, P. et al. Northward shift of historical methane emission hotspots from the livestock sector in China and assessment of potential mitigation options. Agric. For. Meteorol. 272-273, 1–11 (2019).

    Article  ADS  Google Scholar 

  28. Li, T. et al. Enhanced-efficiency fertilizers are not a panacea for resolving the nitrogen problem. Glob. Change Biol. 24, e511–e521 (2018).

    Article  Google Scholar 

  29. Lam, S. K. et al. Next-generation enhanced-efficiency fertilizers for sustained food security. Nat. Food 3, 575–580 (2022).

    Article  PubMed  Google Scholar 

  30. Kanter, D. R. & Searchinger, T. D. A technology-forcing approach to reduce nitrogen pollution. Nat. Sustain. 1, 544–552 (2018).

    Article  Google Scholar 

  31. Timilsena, Y. P. et al. Enhanced efficiency fertilisers: a review of formulation and nutrient release patterns. J. Sci. Food. Agr. 95, 1131–1142 (2015).

    Article  CAS  Google Scholar 

  32. Duan, J. K. et al. Consolidation of agricultural land can contribute to agricultural sustainability in China. Nat. Food 2, 1014–1022 (2021).

    Article  CAS  PubMed  Google Scholar 

  33. Springmann, M. et al. Options for keeping the food system within environmental limits. Nature 562, 519–525 (2018).

    Article  ADS  CAS  PubMed  Google Scholar 

  34. Cai, S. et al. Optimal nitrogen rate strategy for sustainable rice production in China. Nature 615, 73–79 (2023).

    Article  ADS  CAS  PubMed  Google Scholar 

  35. Xu, P. et al. Policy-enabled stabilization of nitrous oxide emissions from livestock production in China over 1978-2017. Nat. Food 3, 356–366 (2022).

    Article  CAS  PubMed  Google Scholar 

  36. Xia, L. L., Lam, S. K., Yan, X. & Chen, D. How does recycling of livestock manure in agroecosystems affect crop productivity, reactive nitrogen losses, and soil carbon balance?. Environ. Sci. Technol. 51, 7450–7457 (2017).

    Article  ADS  CAS  PubMed  Google Scholar 

  37. Uwizeye, A. et al. Nitrogen emissions along global livestock supply chains. Nat. Food 1, 437–446 (2020).

    Article  CAS  Google Scholar 

  38. Erickson, E. D. et al. Biogas production in United States dairy farms incentivized by electricity policy changes. Nat. Sustain. 6, 438–446 (2023).

    Article  Google Scholar 

  39. Wu, Y. Y. et al. Policy distortions, farm size, and the overuse of agricultural chemicals in China. Proc. Natl Acad. Sci. USA 115, 7010–7015 (2018).

    Article  ADS  CAS  PubMed  PubMed Central  Google Scholar 

  40. Zou, T., Zhang, X. & Davidson, E. A. Global trends of cropland phosphorus use and sustainability challenges. Nature 611, 81–87 (2022).

    Article  ADS  CAS  PubMed  Google Scholar 

  41. Ren, C. C., Zhang, X. M., Reis, S. & Gu, B. J. Socioeconomic barriers of nitrogen management for agricultural and environmental sustainability. Agr. Ecosyst. Environ. 333, 107950 (2022).

    Article  CAS  Google Scholar 

  42. Vitousek, P. M. et al. Nutrient imbalances in agricultural development. Science 324, 1519–1520 (2009).

    Article  ADS  CAS  PubMed  Google Scholar 

  43. Wang, C. et al. Ammonia emissions from croplands decrease with farm size in China. Environ. Sci. Technol. 56, 9915–9923 (2022).

    Article  ADS  CAS  PubMed  Google Scholar 

  44. Wu, K. et al. Enhanced sustainable green revolution yield via nitrogen-responsive chromatin modulation in rice. Science 367, eaaz2046 (2020).

    Article  CAS  PubMed  Google Scholar 

  45. Hoesly, R. M. et al. Historical (1750-2014) anthropogenic emissions of reactive gases and aerosols from the Community Emissions Data System (CEDS). Geosci. Model Dev. 11, 369–408 (2018).

    Article  ADS  CAS  Google Scholar 

  46. Chen, Z.-L. et al. Significant contributions of combustion-related sources to ammonia emissions. Nat. Commun. 13, 7710 (2022).

    Article  ADS  CAS  PubMed  PubMed Central  Google Scholar 

  47. Guardia, G. et al. Increasing N use efficiency while decreasing gaseous N losses in a non-tilled wheat (Triticum aestivum L.) crop using a double inhibitor. Agr. Ecosyst. Environ. 319, 107546 (2021).

    Article  CAS  Google Scholar 

  48. Recio, J. et al. Joint mitigation of NH3 and N2O emissions by using two synthetic inhibitors in an irrigated cropping soil. Geoderma 373, 114423 (2020).

    Article  ADS  CAS  Google Scholar 

  49. Yu, F., Wei, C., Deng, P., Peng, T. & Hu, X. Deep exploration of random forest model boosts the interpretability of machine learning studies of complicated immune responses and lung burden of nanoparticles. Sci. Adv. 7, eabf4130 (2021).

    Article  ADS  CAS  PubMed  PubMed Central  Google Scholar 

  50. Grubbs, F. E. Procedures for detecting outlying observations in samples. Technometrics 11, 1–21 (1969).

    Article  Google Scholar 

  51. Box, G. E. P. & Cox, D. R. An analysis of transformations. J. R. Stat. Soc. B. 26, 211–252 (1964).

    Google Scholar 

  52. Cook-Patton, S. C. et al. Mapping carbon accumulation potential from global natural forest regrowth. Nature 585, 545–550 (2020).

    Article  ADS  CAS  PubMed  Google Scholar 

  53. Biau, G. & Scornet, E. A random forest guided tour. Test 25, 197–227 (2016).

    Article  MathSciNet  Google Scholar 

  54. Breiman, L. Random forests. Mach. Learn. 45, 5–32 (2001).

    Article  Google Scholar 

  55. Ishwaran, H., Kogalur, U. B., Gorodeski, E. Z., Minn, A. J. & Lauer, M. S. High-dimensional variable selection for survival data. J. Am. Stat. Assoc. 105, 205–217 (2010).

    Article  MathSciNet  CAS  Google Scholar 

  56. Zhang, K., Li, X., Zheng, D. H., Zhang, L. & Zhu, G. F. Estimation of global irrigation water use by the integration of multiple satellite observations. Water Resour. Res. 58, e2021WR030031 (2022).

    Article  ADS  Google Scholar 

  57. Ray, D. K., Ramankutty, N., Mueller, N. D., West, P. C. & Foley, J. A. Recent patterns of crop yield growth and stagnation. Nat. Commun. 3, 1293 (2012).

    Article  ADS  PubMed  Google Scholar 

  58. Sacks, W. J., Deryng, D., Foley, J. A. & Ramankutty, N. Crop planting dates: an analysis of global patterns. Global Ecol. Biogeogr. 19, 607–620 (2010).

    Article  Google Scholar 

  59. Tian, H. Q. et al. History of anthropogenic Nitrogen inputs (HaNi) to the terrestrial biosphere: a 5 arcmin resolution annual dataset from 1860 to 2019. Earth Syst. Sci. Data 14, 4551–4568 (2022).

    Article  ADS  Google Scholar 

  60. Mueller, N. D. et al. Closing yield gaps through nutrient and water management. Nature 490, 254–257 (2012).

    Article  ADS  CAS  PubMed  Google Scholar 

  61. West, P. C. et al. Leverage points for improving global food security and the environment. Science 345, 325–328 (2014).

    Article  ADS  CAS  PubMed  Google Scholar 

  62. Cui, X. Q. et al. Global mapping of crop-specific emission factors highlights hotspots of nitrous oxide mitigation. Nat. Food 2, 886–893 (2021).

    Article  CAS  PubMed  Google Scholar 

  63. van den Hoogen, J. et al. Soil nematode abundance and functional group composition at a global scale. Nature 572, 194–198 (2019).

    Article  ADS  PubMed  Google Scholar 

  64. Food and Agriculture Organization of the United Nations (FAO). FAOSTAT: FAO Statistical Databases (FAO, 2022); https://www.fao.org/food-agriculture-statistics/en/.

  65. IPCC. Climate Change 2022: Impacts, Adaptation and Vulnerability (eds Pörtner, H. O. et al.) (Cambridge Univ. Press, 2022).

  66. O’Neill, B. C. et al. The scenario model intercomparison project (ScenarioMIP) for CMIP6. Geosci. Model Dev. 9, 3461–3482 (2016).

    Article  ADS  Google Scholar 

  67. Zhu, P. et al. Warming reduces global agricultural production by decreasing cropping frequency and yields. Nat. Clim. Change 12, 1016–1023 (2022).

    Article  ADS  CAS  Google Scholar 

  68. Lange, S. Trend-preserving bias adjustment and statistical downscaling with ISIMIP3BASD (v1.0). Geosci. Model Dev. 12, 3055–3070 (2019).

    Article  ADS  Google Scholar 

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Acknowledgements

This study was supported by the National Natural Science Foundation of China (grant nos. 42325702 to Yi Zheng, 42277086 to P.X. and 42321004 to Yan Zheng), the Natural Science Foundation of Guangdong Province (grant no. 2023A1515012280 to P.X.) and the Research Grants Council of the Hong Kong Special Administrative Region, China (grant no. 16302220 to J.C.H.F.), the Earth and Environmental Systems Sciences Division of the Biological and Environmental Research Office in the Office of Science of the US Department of Energy (DOE) (the Terrestrial Ecosystem Science Scientific Focus Area project and the Reducing Uncertainties in Biogeochemical Interactions through Synthesis and Computing Scientific Focus Area project to J.M.). Oak Ridge National Laboratory is supported by the Office of Science of the DOE under contract DE-AC05-00OR22725. We thank C. P. Ti of the Institute of Soil Science, Chinese Academy of Sciences; S. W. Liu of the Nanjing Agricultural University; and X. Y. Zhan of the Chinese Academy of Agricultural Sciences for providing us with data.

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Authors

Contributions

P.X., G.L., Yi Zheng and J.F. designed the study. P.X. and G.L. performed the research. P.X., G.L. and Yi Zheng analysed the data. P.X., G.L., Yi Zheng, S.H. and J.C.H.F. wrote the initial draft of the paper. B.Z.H., Z.Z., H.S., M.H., J.M., Yan Zheng, X.C., Z.G., L.F., Y.C., X.Z., A.K.H.L., A.C. and S.T. reviewed and revised the paper. All authors contributed to the discussion and interpretation of the results.

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Correspondence to Yi Zheng or Jimmy C. H. Fung.

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Nature thanks Luis Lassaletta, Rongbin Xu and the other, anonymous, reviewer(s) for their contribution to the peer review of this work. Peer reviewer reports are available.

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Extended data figures and tables

Extended Data Fig. 1 Global cropland NH3 emissions mitigation potentials.

Emissions maps of rice (a), wheat (b), and maize (c) at the country scale; the proportions of mitigation potentials to NH3 emissions under the best management scenario for rice (d), wheat (e), and maize (f). “No data” represents no planting of rice, wheat or maize. Map created using Python 3.8.

Source Data

Extended Data Fig. 2 The mitigation potentials for global cropland NH3 emissions under the best management scenario for crops.

All crops (a), rice (b), wheat (c), and maize (d). Map created using Python 3.8.

Source Data

Extended Data Fig. 3 Projected changes in NH3 emissions for 2030–2100 relative to the reference year (2018) when only future temperature changes are accounted for.

SSP-12.6 (a, b) and SSP5-8.5 (c, d) for mid- (2030–2060) and long-term (2061–2100) horizons. Map created using Python 3.8.

Source Data

Extended Data Fig. 4 Projected changes in NH3 emissions for 2030–2100 relative to the reference year (2018) when only future precipitation changes are accounted for.

SSP-12.6 (a, b) and SSP5-8.5 (c, d) for mid- (2030–2060) and long-term (2061–2100) horizons. Map created using Python 3.8.

Source Data

Extended Data Fig. 5 The differences between the global NH3 mitigation potential induced under the best EF-related management scenario and the NH3 emission increases for 2030–2100.

SSP-12.6 (a, b) and SSP5-8.5 (c, d) for mid- (2030–2060) and long-term (2061–2100) horizons. Map created using Python 3.8.

Source Data

Supplementary information

Source data

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Xu, P., Li, G., Zheng, Y. et al. Fertilizer management for global ammonia emission reduction. Nature 626, 792–798 (2024). https://doi.org/10.1038/s41586-024-07020-z

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