Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Article
  • Published:

Recirculation of human-derived nutrients from cities to agriculture across six continents


Recovering human-derived nutrients can advance circular economies by linking increasingly urban global populations with local cropland, offsetting unsustainable fertilizer use and improving access in low-income countries. For 56 of the world’s largest cities, we analyse co-location of urban nutrients with surrounding agricultural needs (that is, the degree to which recoverable nutrients spatially align with crop demands), defining paths forward to close urban nutrient cycles. Estimated nutrient transport distances, which may constrain what recovery strategies are locally feasible, span two orders of magnitude and are often shorter among European, African and Asian cities due to high local cropland density. We further examine how growing nutrient-intensive crops and recovering highly concentrated nutrient products could impact distance and energy requirements. Broadly, locations with high cropland density, nutrient-intensive crops and compact urban area may find agricultural nutrient reuse particularly impactful and achievable, creating opportunities to boost productivity by coupling urban water and regional agriculture systems.

This is a preview of subscription content, access via your institution

Access options

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Fig. 1: Distributions of nutrient transport distances for 56 cities in 2000.
Fig. 2: Recoverable nitrogen quantities and average transport distances.
Fig. 3: The impact of recovery product on transport energy requirements.

Similar content being viewed by others


  1. Godfray, H. C. J. et al. Food security: The challenge of feeding 9 billion people. Science 327, 812–818 (2010).

    Article  CAS  Google Scholar 

  2. Seto, K. C. et al. Urban land teleconnections and sustainability. Proc. Natl Acad. Sci. USA 109, 7687–7692 (2012).

    Article  Google Scholar 

  3. Forkes, J. Nitrogen balance for the urban food metabolism of Toronto, Canada. Resour. Conserv. Recycl. 52, 74–94 (2007).

    Article  Google Scholar 

  4. Villarroel Walker, R., Beck, M. B., Hall, J. W., Dawson, R. J. & Heidrich, O. The energy-water-food nexus: Strategic analysis of technologies for transforming the urban metabolism. J. Environ. Manage. 141, 104–115 (2014).

    Article  CAS  Google Scholar 

  5. Särkilahti, M., Kinnunen, V., Kettunen, R., Jokinen, A. & Rintala, J. Replacing centralised waste and sanitation infrastructure with local treatment and nutrient recycling: Expert opinions in the context of urban planning. Technol. Forecast. Soc. Change 118, 195–204 (2017).

    Article  Google Scholar 

  6. Ghisellini, P., Cialani, C. & Ulgiati, S. A review on circular economy: The expected transition to a balanced interplay of environmental and economic systems. J. Clean. Prod. 114, 11–32 (2016).

    Article  Google Scholar 

  7. Transforming Our World: The 2030 Agenda for Sustainable Development (United Nations, 2015).

  8. Cordell, D., Drangert, J.-O. & White, S. The story of phosphorus: Global food security and food for thought. Glob. Environ. Change 19, 292–305 (2009).

    Article  Google Scholar 

  9. Fowler, D. et al. The global nitrogen cycle in the twenty-first century. Phil. Trans. R. Soc. B 368, 20130164 (2013).

    Article  CAS  Google Scholar 

  10. Manning, D. A. C. Mineral sources of potassium for plant nutrition. A review. Agron. Sustain. Dev. 30, 281–294 (2012).

    Article  CAS  Google Scholar 

  11. Smith, V. H., Tilman, G. D. & Nekola, J. C. Eutrophication: Impacts of excess nutrient inputs on freshwater, marine, and terrestrial ecosystems. Environ. Pollut. 100, 179–196 (1999).

    Article  CAS  Google Scholar 

  12. Bouwman, A. F., Beusen, A. H. W. & Billen, G. Human alteration of the global nitrogen and phosphorus soil balances for the period 1970–2050. Glob. Biogeochem. Cycles 23, GB0A04 (2009).

    Article  CAS  Google Scholar 

  13. Morée, A. L., Beusen, A. H. W., Bouwman, A. F. & Willems, W. J. Exploring global nitrogen and phosphorus flows in urban wastes during the twentieth century. Glob. Biogeochem. Cycles 27, 836–846 (2013).

    Article  CAS  Google Scholar 

  14. Sheldrick, W. F., Syers, J. K. & Lingard, J. A conceptual model for conducting nutrient audits at national, regional, and global scales. Nutr. Cycl. Agroecosys. 62, 61–72 (2002).

    Article  CAS  Google Scholar 

  15. Mihelcic, J. R., Fry, L. M. & Shaw, R. Global potential of phosphorus recovery from human urine and feces. Chemosphere 84, 832–839 (2011).

    Article  CAS  Google Scholar 

  16. Trimmer, J. T., Cusick, R. D. & Guest, J. S. Amplifying progress toward multiple development goals through resource recovery from sanitation. Environ. Sci. Technol. 51, 10765–10776 (2017).

    Article  CAS  Google Scholar 

  17. Green Growth and Climate Resilience: National Strategy for Climate Change and Low Carbon Development (Republic of Rwanda, 2011).

  18. Steffen, W. et al. Planetary boundaries: Guiding human development on a changing planet. Science 347, 1259855 (2015).

    Article  CAS  Google Scholar 

  19. Xu, M. et al. Gigaton problems need gigaton solutions. Environ. Sci. Technol. 44, 4037–4041 (2010).

    Article  CAS  Google Scholar 

  20. Mihelcic, J. R. et al. The grandest challenge of all: The role of environmental engineering to achieve sustainability in the world’s developing regions. Environ. Eng. Sci. 34, 16–41 (2016).

    Article  CAS  Google Scholar 

  21. Seto, K. C., Golden, J. S., Alberti, M. & Turner, B. L. Sustainability in an urbanizing planet. Proc. Natl Acad. Sci. USA 114, 8935–8938 (2017).

    Article  CAS  Google Scholar 

  22. World Urbanization Prospects: The 2014 Revision, (ST/ESA/SER.A/366) (United Nations, Department of Economic and Social Affairs, Population Division, 2015).

  23. Badami, M. G. & Ramankutty, N. Urban agriculture and food security: A critique based on an assessment of urban land constraints. Glob. Food Secur. 4, 8–15 (2015).

    Article  Google Scholar 

  24. Verbyla, M. E., Oakley, S. M. & Mihelcic, J. R. Wastewater infrastructure for small cities in an urbanizing world: Integrating protection of human health and the environment with resource recovery and food security. Environ. Sci. Technol. 47, 3598–3605 (2013).

    Article  CAS  Google Scholar 

  25. Wald, C. The new economy of excrement. Nature 549, 146–148 (2017).

    Article  CAS  Google Scholar 

  26. Ostara Overview: Nutrient Management Solutions (Ostara, 2018).

  27. Mehta, C. M., Khunjar, W. O., Nguyen, V., Tait, S. & Batstone, D. J. Technologies to recover nutrients from waste streams: A critical review. Crit. Rev. Environ. Sci. Technol. 45, 385–427 (2015).

    Article  Google Scholar 

  28. van Loosdrecht, M. C. M. & Brdjanovic, D. Anticipating the next century of wastewater treatment. Science 344, 1452–1453 (2014).

    Article  CAS  Google Scholar 

  29. Diener, S. et al. A value proposition: Resource recovery from faecal sludge—Can it be the driver for improved sanitation? Resour. Conserv. Recycl. 88, 32–38 (2014).

    Article  Google Scholar 

  30. Larsen, T. A., Alder, A. C., Eggen, R. I. L., Maurer, M. & Lienert, J. Source separation: Will we see a paradigm shift in wastewater handling? Environ. Sci. Technol. 43, 6121–6125 (2009).

    Article  CAS  Google Scholar 

  31. Metson, G. S., MacDonald, G. K., Haberman, D., Nesme, T. & Bennett, E. M. Feeding the corn belt: opportunities for phosphorus recycling in US agriculture. Sci. Total Environ. 542, 1117–1126 (2016).

    Article  CAS  Google Scholar 

  32. Tran, Q. K., Schwabe, K. A. & Jassby, D. Wastewater reuse for agriculture: Development of a regional water reuse decision-support model (RWRM) for cost-effective irrigation sources. Environ. Sci. Technol. 50, 9390–9399 (2016).

    Article  CAS  Google Scholar 

  33. Van Drecht, G., Bouwman, A. F., Harrison, J. & Knoop, J. M. Global nitrogen and phosphate in urban wastewater for the period 1970 to 2050. Glob. Biogeochem. Cycles 23, GB0A03 (2009).

    Google Scholar 

  34. Friedler, E., Butler, D. & Alfiya, Y. in Source Separation and Decentralization for Wastewater Management (eds. Larsen, T. A. et al.) 241–258 (IWA Publishing, London, 2013).

  35. Ewing, R., Hamidi, S., Grace, J. B. & Wei, Y. D. Does urban sprawl hold down upward mobility? Landsc. Urban Plan. 148, 80–88 (2016).

    Article  Google Scholar 

  36. Small, C. & Nicholls, R. J. A global analysis of human settlement in coastal zones. J. Coast. Res. 19, 584–599 (2003).

    Google Scholar 

  37. Food and Agricultural Organization Statistics Division (FAOSTAT, 2018, accessed 21 April 2018);

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

    Article  CAS  Google Scholar 

  39. Alexandratos, N. & Bruinsma, J. World Agriculture Towards 2030/2050: The 2012 Revision (FAO, 2012).

  40. d’Amour, C. B. et al. Future urban land expansion and implications for global croplands. Proc. Natl Acad. Sci. USA 114, 8939–8944 (2017).

    Article  CAS  Google Scholar 

  41. Pakistan Food Security Bulletin: Issue 6, August 2017 (Vulnerability Analysis and Mapping Unit, World Food Programme, 2017).

  42. Hogeboom, R. J. & Hoekstra, A. Y. Water and land footprints and economic productivity as factors in local crop choice: The case of silk in Malawi. Water 9, 802 (2017).

    Article  Google Scholar 

  43. Tchobanoglous, G., Stensel, H. D., Tsuchihashi, R., & Burton, F. Wastewater Engineering: Treatment and Resource Recovery (McGraw-Hill, New York, 2014).

  44. Etter, B., Tilley, E., Khadka, R. & Udert, K. M. Low-cost struvite production using source-separated urine in Nepal. Water Res. 45, 852–862 (2011).

    Article  CAS  Google Scholar 

  45. Tarpeh, W. A., Barazesh, J. M., Cath, T. Y. & Nelson, K. L. Electrochemical stripping to recover nitrogen from source-separated urine. Environ. Sci. Technol. 52, 1453–1460 (2018).

  46. Wilsenach, J. A., Schuurbiers, C. A. H. & van Loosdrecht, M. C. M. Phosphate and potassium recovery from source separated urine through struvite precipitation. Water Res. 41, 458–466 (2007).

    Article  CAS  Google Scholar 

  47. Maurer, M., Schwegler, P. & Larsen, T. A. Nutrients in urine: Energetic aspects of removal and recovery. Water Sci. Technol. 48, 37–46 (2003).

    Article  CAS  Google Scholar 

  48. Progress on Drinking Water, Sanitation and Hygiene: 2017 Update and SDG Baselines (WHO/UNICEF, 2017).

  49. Malik, O. A., Hsu, A., Johnson, L. A. & de Sherbinin, A. A global indicator of wastewater treatment to inform the Sustainable Development Goals (SDGs). Environ. Sci. Policy 48, 172–185 (2015).

    Article  Google Scholar 

  50. Samberg, L. H., Gerber, J. S., Ramankutty, N., Herrero, M. & West, P. C. Subnational distribution of average farm size and smallholder contributions to global food production. Environ. Res. Lett. 11, 124010 (2016).

    Article  Google Scholar 

  51. Monfreda, C., Ramankutty, N. & Foley, J. A. Farming the planet: 2. Geographic distribution of crop areas, yields, physiological types, and net primary production in the year 2000. Glob. Biogeochem. Cycles 22, GB1022 (2008).

    Article  CAS  Google Scholar 

  52. Wichmann, W. IFA World Fertilizer Use Manual (International Fertilizer Association, 1992).

  53. World Database of Large Urban Areas, 1950–2050 (Nordpil, 2010, accessed 10 June 2017);

  54. Standard Country or Area Codes for Statistical Use (M49): Methodology (United Nations Statistics Division, 2017, accessed 10 June 2017);

  55. Gridded Population of the World, Version 4 (GPWv4): Population Count Adjusted to Match 2015 Revision of UN WPP Country Totals (Center for International Earth Science Information Network, 2016).

  56. Gridded Population of the World, Version 4 (GPWv4): Population Density Adjusted to Match 2015 Revision of UN WPP Country Totals (Center for International Earth Science Information Network, 2016).

  57. Global 30 Arc-Second Elevation (GTOPO30) (USGS, 1996).

  58. Gridded Population of the World, Version 4 (GPWv4): Land and Water Area (Center for International Earth Science Information Network, 2016).

  59. World Development Report: Reshaping Economic Geography (The International Bank for Reconstruction and Development/The World Bank, 2009).

  60. Martellozzo, F. et al. Urban agriculture: A global analysis of the space constraint to meet urban vegetable demand. Environ. Res. Lett. 9, 064025 (2014).

    Article  Google Scholar 

  61. Seto, K. C., Güneralp, B. & Hutyra, L. R. Global forecasts of urban expansion to 2030 and direct impacts on biodiversity and carbon pools. Proc. Natl Acad. Sci. USA 109, 16083–16088 (2012).

    Article  Google Scholar 

  62. Mayer, B. K. et al. Total value of phosphorus recovery. Environ. Sci. Technol. 50, 6606–6620 (2016).

    Article  CAS  Google Scholar 

  63. Pradhan, S. K., Mikola, A. & Vahala, R. Nitrogen and phosphorus harvesting from human urine using a stripping, absorption, and precipitation process. Environ. Sci. Technol. 51, 5165–5171 (2017).

    Article  CAS  Google Scholar 

  64. Shoener, B. D., Bradley, I. M., Cusick, R. D. & Guest, J. S. Energy positive domestic wastewater treatment: The roles of anaerobic and phototrophic technologies. Environ. Sci. Process. Impacts 16, 1204–1222 (2014).

    Article  CAS  Google Scholar 

  65. Gellings, C. W. & Parmenter, K. E. in Efficient Use and Conservation of Energy Vol. 11 (eds. Gellings, C. W. & Blok, K.) (UNESCO, EOLSS Publishers, Paris, 2004);

  66. Hauke, J. & Kossowski, T. Comparison of values of Pearson’s and Spearman’s correlation coefficient on the same sets of data. Quaest. Geogr. 30, 87–93 (2011).

    Article  Google Scholar 

  67. Ramankutty, N., Evan, A. T., Monfreda, C. & Foley, J. A. Farming the planet: 1. Geographic distribution of global agricultural lands in the year 2000. Glob. Biogeochem. Cycles 22, GB1003 (2008).

    Article  CAS  Google Scholar 

  68. GDP per Capita (Current US$). World Bank Open Data (World Bank, 2017, accessed 9 October 2017);

  69. Vargha, A. & Delaney, H. D. The Kruskal–Wallis test and stochastic homogeneity. J. Educ. Behav. Stat. 23, 170–192 (1998).

    Article  Google Scholar 

Download references


The authors acknowledge the Illinois Distinguished Fellowship at the University of Illinois at Urbana-Champaign for funding support for J.T.T., and thank R. Cusick for discussions related to the recovery of crystal products.

Author information

Authors and Affiliations



J.S.G. and J.T.T. conceived of the research. J.T.T collected the data and performed the analysis. J.T.T. and J.S.G. interpreted results and wrote the paper.

Corresponding author

Correspondence to Jeremy S. Guest.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

Publisher’s note: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary information

Supplementary Information

Supplementary Methods, Supplementary Figures 1-8, Supplementary Tables 1-15, Supplementary References 1–33

Supplementary Table 6

Data on nutrient mass and distance

Supplementary Table 15

Data on road distance between each city and croplands under study

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Trimmer, J.T., Guest, J.S. Recirculation of human-derived nutrients from cities to agriculture across six continents. Nat Sustain 1, 427–435 (2018).

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI:

This article is cited by


Quick links

Nature Briefing Anthropocene

Sign up for the Nature Briefing: Anthropocene newsletter — what matters in anthropocene research, free to your inbox weekly.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing: Anthropocene