Chapter 3 summary
Transforming food systems: implications for phosphorus
Chapter authors: Dana Cordell, Tim G. Benton, Paul J.A. Withers, Penny J. Johnes, Tina-Simone Neset, Bryan M. Spears • 10min read
Chapter highlights
Managing phosphorus underpins the sustainability of the food system and is vital in achieving future food security. Strategies to deliver phosphorus sustainability include a transition to circular phosphorus value chains, land-use planning approaches that support greater phosphorus use efficiency and a reduction in consumption of animal products. Affordable access to sustainable phosphorus sources is imperative to ensure food provision for all and to protect the livelihoods of smallholder and marginal farmers.
Introduction
How does phosphorus security underpin sustainable food systems?
All farmers need access to phosphorus to grow crops, regardless of what they grow or where they farm. Yet, access to affordable and sustainable sources of phosphorus is, currently, not guaranteed. At the same time, excess phosphorus use can harm aquatic ecosystems and in turn the food, ecosystem and agricultural services they support. Managing phosphorus sustainably, therefore, underpins the sustainability of the food system and is vital in achieving future food security. To make progress towards a sustainable global food system we must take a multiple-stressor mitigation approach. This must address phosphorus use in addition to other essential macro- and micro-nutrient sources required for food production and security, such as nitrogen and vitamin A. This will be critical in efforts to reduce the impact of food production on climate change, human and ecosystem health, and inequalities in access to nutritious food from local to global scale. Efforts focused on single-stressor action are not sustainable and will be unlikely to tackle the scale of the challenge. Multiple United Nations’ Sustainable Development Goals demand a transformation to more sustainable food systems, however, the role of phosphorus management in food systems is not yet sufficiently addressed. ‘Phosphorus security’ envisages a world where all farmers have access to sufficient phosphorus to grow enough food to feed a growing population a healthy diet, while ensuring farmer livelihoods and minimising detrimental environmental and social impacts.
Actions to improve global phosphorus security must be underpinned by a comprehensive understanding of food systems and the flows of phosphorus within them. Such actions should be co-developed with relevant stakeholders to achieve food security whilst delivering multiple benefits to society. This will decrease the likelihood of ‘lock-ins’, where actors are unwilling or unable to exit a position because of sunk infrastructure costs, regulations, or penalties. For example, while phosphorus recovery will be essential, investing in capital-intensive phosphorus recovery technologies that do not produce phosphorus in the biochemical form required for growing crops, and are more energy-intensive to produce than chemical fertilisers, may not be the best use of financial resources.
One significant challenge to overcome concerning the global food system is the equitable supply of, and access to, phosphorus. Only a few countries control the bulk of non-renewable phosphate reserves and production, due to natural geological phosphate formations. Most countries are import-dependent and hence vulnerable to price shocks, supply disruptions, and import barriers, which can disrupt food security and farmer livelihoods if not sufficiently managed.
In the following section, we summarise some of the key challenges and solutions to achieving phosphorus security within a food system under transformation.
Key issue 3.1
Business as usual is unsustainable: we must produce healthier foods, using appropriate phosphorus inputs
The challenge
Our food system is a significant cause of nutrient pollution in terrestrial, freshwater and marine ecosystems, and of global climate change, while more than half the global population are acutely hungry, malnourished, overweight, or obese. The public health and ecological costs of the current food system exceed the economic value of agriculture. The food system must undergo a substantial transformation to become environmentally sustainable and provide nutritional security for all. This means sustainable phosphorus strategies must directly support—not hinder—this change. On the current path, the global food system will increase the mining of finite phosphate rock to produce fertiliser, feed additives and food supplements, and is not tracking towards a circular phosphorus system (driven on recycled phosphorus inputs).
The solution
Global food systems must produce, actively support, and provide access to nutritious food and diets for all. This shift, from ‘market-led’ to ‘sustainable’ food security, can reduce phosphorus demand and adverse impacts on ecosystems and society. At the same time, strategies to deliver better phosphorus sustainability – including circular phosphorus value chains – can benefit agricultural economies, whilst effective monitoring systems, data sharing, and knowledge exchange can ensure strategies adapt to a transforming food system..
Key issue 3.2
Increasing global consumption of animal products is increasing phosphorus demand
The challenge
The amount of phosphorus required to produce the average per capita global diet has increased by 38% in the last 50 years, due to the rise in consumption of animal products, increase in average per capita consumption and increased food waste. Excluding phosphorus-efficient grass-based systems, a large proportion of cropland is needed to support intensive meat and dairy production through concentrated animal feeding operations. This trend is driving increased mining of phosphate rock for fertilisers, animal feed and supplements. Unhealthy diets, including overconsumption of animal products, are also a significant contributor to non-communicable diseases.
The solution
Reduced consumption of animal products (especially from intensive production systems in some regions) may reduce global agricultural phosphorus demand and contribute to healthier environments. Increased awareness amongst policymakers and the public of both the environmental impacts of phosphorus use in food production, and the human health risks of excessive consumption of animal products, will be an essential driver of change towards more plant-based proteins. Knowledge exchange between academics, stakeholders and the public can help identify solutions to support a transition to more phosphorus sustainable consumer behaviour, as could policy and regulatory changes (including internalising the environmental costs into food pricing).
Key issue 3.3
Balancing intensive agriculture with low input farming
The challenge
Agricultural intensification increases productivity yet increasing phosphorus inputs to crops can also over-enrich adjacent land and waterbodies with nutrients. Lowering inputs reduces environmental risk and promotes biodiversity but may restrict yield in the long term. Strategies need to provide the right balance of intensification to avoid the need to convert more land to agriculture. Optimising the multitude of costs and benefits and taking account of direct and indirect impacts can be challenging and context-specific. The challenge we face is in developing low phosphorus input farming systems which can sustain food production.
The solution
There is an opportunity to develop novel land-use planning approaches to support more sustainable phosphorus use across multiple and interacting contexts. These include agricultural production, ecosystem and human health, local economies and regional capacity for institutional planning and coordination. Sustainable farming systems in which animal and crop production are more integrated and animal residues and manures are treated as valuable phosphorus resources, will support efforts to increase phosphorus use efficiency within landscapes while reducing negative impacts on aquatic and terrestrial ecosystems.
Key issue 3.4
Many smallholder farmers lack access to phosphorus, threatening their livelihoods
The challenge
Currently, 1 in 7 farmers cannot access or afford phosphorus fertilisers to increase productivity, impacting their ability to maintain food security and livelihoods. Those farmers most affected are rural smallholder farming families, particularly in less economically developed countries, but also in some more economically developed countries. There are marked global inequalities in access to phosphorus as a resource, leading to substantial inequalities in the distribution of risks to food security. Fluctuation in phosphate prices and disruption in supply can threaten food security in some regions, especially impacting smallholder farmers in less economically developed countries.
The solution
Affordable access to sustainable phosphorus sources is imperative to ensure food provision for all and to protect the livelihoods of smallholder and marginal farmers. Multiple options exist to help improve phosphorus access in these communities. These include access to credit, extension services, investment in sustainable infrastructure (such as local phosphorus recycling systems from food waste and sanitation where available), and knowledge exchange to support better phosphorus use efficiency and recycling. Developing the capacity to recycle phosphorus from local and regional food systems where available can help to shift reliance away from mineral phosphorus fertilisers.
Conclusion
The food system must undergo a substantial transformation to become environmentally sustainable and provide nutritional security for all. Strategies to deliver better phosphorus sustainability can and need to be aligned with this food system transformation. This includes a transition to circular phosphorus value chains based on diverse renewable sources and high efficiency, and land-use planning approaches that promote phosphorus recycling, such as mixed rather than specialist farming. In many regions, reducing the over-consumption of animal products beyond recommended levels for healthy diets - especially when sourced from intensive production systems - is required, which can also dramatically reduce phosphorus over-consumption. In other regions, particularly low-income countries and vulnerable communities, increasing affordable access to sustainable phosphorus sources will be a priority. Opportunities for this may include access to credit, extension services, investment in sustainable infrastructure (such as local phosphorus recycling systems from food waste and sanitation where available), and knowledge exchange to support better phosphorus use efficiency and recycling.
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The full chapter contains references to the evidence provided above and acknowledgements of images.
Suggested citation for this chapter: D. Cordell, T.G. Benton, P.J.A. Withers, P.J. Johnes, T.S. Neset, B.M. Spears. (2022) Chapter 3. Transforming food systems: implications for phosphorus, in: W.J. Brownlie, M.A. Sutton, K.V. Heal, D.S. Reay, B.M. Spears (eds.), Our Phosphorus Future. UK Centre for Ecology and Hydrology, Edinburgh. doi: 10.13140/RG.2.2.10598.91201