Nutrient Cycles

Food production is the main source of nitrogen pollution. See our discussion of nutrient pollution for information on broader causes and ecological impacts of them.

Food and Eutrophication

Agriculture is the main source of nitrogen and phosphorous runoff, which leads to eutrophication. Generally, meat and animal products lead to much greater eutrophication over their lifetime than plant-based foods.

The image: "eutrophication_by_food.svg" cannot be found!

Sources: FAO 1, Poore and Nemecek 2.

In addition to adopting plant-based diets, fertilizer runoff and eutrophication can be reduced through farming practices such as no-till and precision farming, and intensive farming methods such as greenhouses.

Nutrient Availability

World economical reserves of phosphate rock, the main source of the critical element phosphorous in fertilizers, are between 60 3 and 69 billion 4 tons, or about 270-310 years of production at 2014 levels 4. However, most known reserves are in Morocco 4, posing a risk to security of supply, and reserve estimates are in doubt 5. There is not a clear reason to worry, but a thorough audit of reserves from an organization such as the Food and Agriculture Organization of the United Nations would be of value.

The following phosphorous conservation opportunities have been estimated.

The image: "phosphorous_conservation.svg" cannot be found!

Sources: Gilmour et al. 6, Satorious et al. 7, Udawatta et al. 8.

References

  1. Food and Agriculture Organization. "Nutritive Factors". Accessed January 7, 2020.

  2. Poore, J., Nemecek, T. "Reducing food’s environmental impacts through producers and consumers". Science 360(6392), pp. 987-992. June 2018.

  3. Van Kauwenbergh, S. "World Phosphate Rock Reserves and Resources". International Fertilizer Development Center. September 2010.

  4. Jasinski, S. "Phosphate Rock". U.S. Geological Survey, Mineral Commodity Summaries. January 2016. 2 3

  5. Edixhoven, J., Gupta, J., Savenije, H. "Recent revisions of phosphate rock reserves and resources: a critique". Earth Syst. Dynam., 5, pp. 491-507. December 2014.

  6. Gilmour, D., Blackwood, D., Comber, S., Thornell, A. "Identifying human waste contribution of phosphorus loads to domestic wastewater". 11th International Conference on Urban Drainage, Edinburgh, Scotland, UK. 2008.

  7. Sartorius, C., von Horn, J., Tettenborn, F. "Phosphorus recovery from wastewater - state-of-the-art and future potential". Conference presentation at Nutrient Recovery and Management Conference organised by International Water Association (IWA) and Water Environment Federation (WEF) in Florida, USA. 2011.

  8. Udawatta, R., Henderson, G., Jones, J., Hammer, D. "Phosphorus and nitrogen losses in relation to forest, pasture and row-crop land use and precipitation distribution in the midwest USA". Journal of Water Science 24(3), pp. 269-281. 2011.