The story of phosphorus: Global food security and food for thought

https://doi.org/10.1016/j.gloenvcha.2008.10.009Get rights and content

Abstract

Food production requires application of fertilizers containing phosphorus, nitrogen and potassium on agricultural fields in order to sustain crop yields. However modern agriculture is dependent on phosphorus derived from phosphate rock, which is a non-renewable resource and current global reserves may be depleted in 50–100 years. While phosphorus demand is projected to increase, the expected global peak in phosphorus production is predicted to occur around 2030. The exact timing of peak phosphorus production might be disputed, however it is widely acknowledged within the fertilizer industry that the quality of remaining phosphate rock is decreasing and production costs are increasing. Yet future access to phosphorus receives little or no international attention. This paper puts forward the case for including long-term phosphorus scarcity on the priority agenda for global food security. Opportunities for recovering phosphorus and reducing demand are also addressed together with institutional challenges.

Introduction

Food production is fundamental to our existence, yet we are using up the world's supply of phosphorus, a critical ingredient in growing food. Today, phosphorus is mostly obtained from mined rock phosphate and is often combined in mineral fertilizers with sulphuric acid, nitrogen, and potassium. Existing rock phosphate reserves could be exhausted in the next 50–100 years (Steen, 1998, Smil, 2000b, Gunther, 2005). The fertilizer industry recognises that the quality of reserves is declining and the cost of extraction, processing and shipping is increasing (Runge-Metzger, 1995, Driver, 1998, Smil, 2000b, EcoSanRes, 2003). Box 1 outlines the key issues.

Common responses to resource scarcity problems include higher prices, more efficient resource use, the introduction of alternatives, and the recovery of the resource after use. The use of phosphorus is becoming more efficient, especially in Europe. Farmers in Europe and North America are increasingly avoiding over fertilization, and are ploughing straw and animal manure into agricultural soils, partly to recycle phosphorus (European Fertilizer Manufacturers Association, 2000). However, most of the discussion about efficient phosphorus use, and most of the measures to achieve this, have been motivated by concerns about toxic algal blooms caused by the leakage of phosphorus (and nitrogen) from agricultural land (Sharpley et al., 2005). While such measures are essential, they will not by themselves be sufficient to achieve phosphorus sustainability. A more integrated and effective approach to the management of the phosphorus cycle is needed—an approach which addresses future phosphorus scarcity and hence explores synergies that reduce leakage and recover and reuse phosphorus.

The following sections of this paper assess the historical, current and future availability of phosphorus in the context of global food security. Possible options for meeting the world's future phosphorus demand are outlined and institutional opportunities and obstacles are discussed.

Section snippets

Humanity's addiction to phosphate rock

Historically, crop production relied on natural levels of soil phosphorus and the addition of locally available organic matter like manure and human excreta (Mårald, 1998). To keep up with increased food demand due to rapid population growth in the 20th century, guano and later rock phosphate were applied extensively to food crops (Brink, 1977, Smil, 2000b). Fig. 1 gives a broad outline of the evolution of phosphorus fertilizer use for food production.

The Chinese used human excreta (‘night

Demand for food, demand for fertilizers

Following more than half a century of generous application of inorganic high-grade phosphorus and nitrogen fertilizers, agricultural soils in Europe and North America are now said to have surpassed ‘critical’ phosphorus levels, and thus only require light applications to replace what is lost in harvest (FAO, 2006; European Fertilizer Manufacturers Association, 2000). Consequently, demand for phosphorus in these regions has stabilized or is decreasing.

However in developing and emerging economies

Peak phosphorus—a sequel to peak oil?

As first highlighted by Hubbert in 1949 (Hubbert, 1949), production of oil reserves will at some time reach a maximum rate or ‘peak’ based on the finite nature of non-renewable resources, after which point production will decline. In a similar way, the rate of global production of high-grade phosphate rock will eventually reach a maximum or peak. Hubbert and later others argue that the important period is not when 100% of the reserve is depleted, but rather when the high quality, highly

Options for sustainable phosphorus use and management

There is no single ‘quick fix’ solution to current dependence on phosphate rock for phosphorus fertilizers. However there are a number of technologies and policy options that exist today at various stages of development – from research to demonstration and implementation – that together could meet future phosphate fertilizer needs for global food production. Implementing these measures will inevitably require an integrated approach that looks beyond the current focus on reducing agricultural

Institutional and attitudinal barriers and opportunities

Since a global phosphorus scarcity crisis is imminent, as we have demonstrated in the sections above, why is it not being discussed in relation to global food security or global environmental change? What are the current barriers to addressing a phosphorus ‘crisis’ and what are the underlying reasons for the lack of attention to nutrient recirculation options such as urine reuse?12

Conclusions

This paper outlines how humanity became addicted to phosphate rock, and examines the current and future implications of this dependence on a non-renewable resource. Global demand for crops will continue to rise over the next half century, increasing the demand for phosphate fertilizers. However, modern agriculture is currently relying on a non-renewable resource and future phosphate rock is likely to yield lower quality phosphorus at a higher price. If significant physical and institutional

Acknowledgements

This research has been undertaken as a doctoral research project funded by an Australian Postgraduate Award (APA) issued by the Australian Department of Education, Science and Training (www.dest.gov.au).

References (135)

  • D. Buckingham et al.

    Phosphate Rock Statistics 1900–2002

    (2004)
  • Buckingham, D.A., Jasinski, S.M., 2006. Phosphate Rock Statistics, Historical Statistics for Mineral and Material...
  • CEEP, 2008. SCOPE Newsletter, Number 70....
  • Cordell, D., 2006. Urine Diversion and Reuse in Australia: A homeless paradigm or sustainable solution for the future?....
  • Cordell, D., 2007. More Nutrition per Dropping: From Global Food Security to National ‘Phosphorus Sovereignty’, poster...
  • Cordell, D., Neset, T.S.S., Drangert, J.-O., White, S., in press. Preferred future phosphorus scenarios: a framework...
  • H. Corell

    Letter dated 29 January 2002 from the Under-Secretary-General for Legal Affairs the Legal Counsel addressed to the President of the Security Council

  • Department of Commerce

    National Programme for Organic Production, India Organic

    (2005)
  • Déry, P., Anderson, B., 2007. Peak phosphorus. Energy Bulletin, 08/13/2007. Available:...
  • Drangert, J-O., 1998. Fighting the urine blindness to provide more sanitation options. Water SA 24, No...
  • J. Driver

    Phosphates recovery for recycling from sewage and animal waste

    Phosphorus and Potassium

    (1998)
  • Earth Policy Institute

    Oil and Food: A Rising Security Challenge

    (2005)
  • EcoSanRes

    Closing the Loop on Phosphorus

    (2003)
  • EcoSanRes, 2008. Sweden-China Erdos Eco-Town Project Dongsheng, Inner Mongolia, Stockholm Environment Institute (SEI)....
  • European Fertilizer Manufacturers Association

    Phosphorus: Essential Element for Food Production

    (2000)
  • J.H.J. Ensink et al.

    A nationwide assessment of wastewater use in Pakistan: an obscure activity or a vitally important one?

    Water Policy

    (2004)
  • S. Esrey et al.

    Closing the Loop: Ecological Sanitation for Food Security

    (2001)
  • EU, 2007. Council Regulation (EC) No. 834/2007 of 28 June 2007 on organic production and labelling of organic products...
  • European Commission, 2000. Directive 2000/53/EC of the European Parliament and of the Council of 18th September 2000 on...
  • Falkenmark, M., 2008. Overarching summary of workshop contributons and personal reflections. World Water Week, August...
  • M. Falkenmark et al.

    Neither water nor food security without a major shift in thinking—a water-scarcity close-up

  • FAO

    Urban and Peri-urban Agriculture

    (1999)
  • FAO

    Fertilizer Requirements in 2015 and 2030

    (2000)
  • FAO

    The State of Food Security in the World, Monitoring Progress Towards the World Food Summit and Millennium Development Goals

    (2004)
  • FAO, 2004b. The Use of Phosphate Rocks for Sustainable Agriculture Technical. In: F. Zapata (Ed.), Joint FAO/IAEA...
  • FAO, 2005a. Assessment of the World Food Security Situation, Food and Agricultural Organisation of the United Nations....
  • FAO, 2005b. The Special Program for Food Security, Food and Agriculture Organisation of the United Nations. Available:...
  • FAO, 2006. Plant Nutrition for Food Security: A Guide for Integrated Nutrient Management, FAO Fertilizer And Plant...
  • FAO, 2007a. Current World Fertilizer Trends and Outlook to 2010/11. Food and Agriculture Organisation of the United...
  • FAO, 2007b. Food for the Cities Homepage. Rome, Food and Agriculture Organisation of the United...
  • FAO, 2007c. Organic agriculture and food availability. International Conference on Organic Agriculture and Food...
  • FAO

    Efficiency of soil and fertilizer phosphorus use: reconciling changing concepts of soils phosphorus behaviour with agronomic information

  • FAO, 2008b. High-level conference on world food security: the challenges of climate change and bioenergy. Soaring food...
  • Fertilizer Week, 2008. Industry ponders the impact of China's trade policy. Thursday Markets Report, 24th April 2008,...
  • Food21, 2005. Research Programme on sustainable food production, Swedish University of Agricultural Science, Uppsala,...
  • Fraiture, C.D., 2007. Future Water Requirements for Food—Three Scenarios, International Water Management Institute...
  • Fresco, L., 2003. Plant nutrients: what we know, guess and do not know, Assistant Director-General. Agriculture...
  • Gardner, G., Halweil, B., 2000. Overfed and Underfed: The Global Epidemic of Malnutrition. In: Peterson, J. (Ed.),...
  • GCP, 2008. The Global Carbon Project. A programme of the Earth Systems Science Partnership,...
  • GECAFS, 2006. Conceptualising Food Systems for Global Environmental Change (GEC) Research, GECAFS Working Paper 2. P.J....
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