Agroecology 3 min

Around 50% of soil-available phosphorus comes from mineral fertilisers in agricultural systems worldwide

PRESS RELEASE - Plants need phosphorus to grow. Farmers’ use of mineral phosphorus fertilisers has greatly increased soil phosphorus fertility and, consequently, crop yields. However, these fertilisers are made from rock phosphate, a non-renewable resource that is patchily distributed across the Earth. Researchers at INRAE and Bordeaux Sciences Agro have modelled, for each country, the fraction of soil-available phosphorus that is derived from the use of mineral phosphorus fertiliser. They also examined changes in these figures over time, starting in the mid 20th century. Published in Nature Geoscience, their results show that in 2017, around 50% of the world's soil-available phosphorus in agricultural systems comes from the use of mineral phosphorus fertilisers. This global data however hides dramatic differences among regions. While Western Europe, North America, and Asia are all situated above 60%, South America and Africa are around 40% and 30%, respectively. This finding underscores that agricultural systems are extremely dependent on mineral phosphorus fertilisers. The study highlights the importance of accelerating the agroecological transition in the Global North, whose countries must preserve their acquired soil fertility and improve the flow of agricultural and urban effluents to the soil. Remaining phosphate rock resources should be given to the Global South, especially to African countries, whose soils remain phosphorus deficient, a reality that limits agricultural production.

Published on 06 January 2023

illustration Around 50% of soil-available phosphorus comes from mineral fertilisers in agricultural systems worldwide

Phosphorus occurs naturally in soils, but its levels and relative availability vary by global region and soil type. Since the 1950s, the use of mineral phosphorus fertilisers has boosted soil-available phosphorus and, thus, agricultural yields. However, these fertilisers are created via the mining and chemical processing of rock phosphate, a non-renewable natural resource that is unevenly distributed across the globe. For example, 70% of rock phosphate is in Morocco, while there is almost none to be found in Europe. Furthermore, the transformation of rock phosphate releases large amounts of pollution. Researchers agree that, at current rates of extraction, we will likely reach peak phosphorus (the point of maximum resource production) by 2050. Such will probably lead to an increase in fertiliser prices and greater geopolitical tensions. Against this backdrop, it is essential to clarify how past and present patterns of mineral phosphorus fertiliser usage have affected the dependence of current agricultural systems on this finite resource.

Scientists from INRAE and Bordeaux Sciences Agro therefore decided to quantify the percentage of soil-available phosphorus that originates from mineral fertilisers, defined as the soil’s anthropogenic signature of phosphorus. They developed a model to simulate country-specific patterns of soil-available phosphorus in agricultural systems worldwide for the period from 1950 to 2017. This approach utilised data on stocks of soil-available phosphorus, crop yields, mineral fertiliser use, livestock numbers, and international trade. The calculations were based on a country’s average agricultural soil, which was defined by each country’s use of grasslands and crops within agricultural systems with varying levels of intensification.

Soil fertility is highly dependent on synthetic mineral fertilisers

Globally, the anthropogenic signature of phosphorus is around 47% (±8%), which suggests that, at present, approximately half of soil phosphorus fertility is attributable to the use of mineral fertilisers. This result reflects the intensification of agricultural systems that has taken place worldwide. Indeed, many countries have relied heavily on synthetic fertilisers since the 1950s.

This work highlights the strong spatial and temporal disparities in how dependent different countries are on mineral phosphorus fertilisers. Anthropogenic signatures of phosphorus have risen sharply in Western Europe and North America since the 1950s, and they exceeded 60% in 2017. Since the 1970s, signatures in Western European countries have plateaued, thanks to the decreased use of mineral fertilisers. Livestock manure has helped partially meet phosphorus needs. In Asia, signatures began increasing in the 1970s, which is when countries in that region experienced the Green Revolution, fuelled by massive quantities of mineral fertilisers. The signatures of Asian countries have now caught up and surpassed those of Western European countries. This growth continues, driven by a weighty perpetual reliance on mineral phosphorus fertilisers. In 2017, signatures in South America and Eastern Europe were lower, around 40%. Finally, countries in Africa and Oceania had signatures below 30%, reflecting their more limited use of mineral fertilisers historically.

World map of anthropogenic phosphorus signature
Anthropogenic signatures of soil-available phosphorus in agricultural systems in 2017. In grey are the countries for which data are lacking, and in hatched grey are the countries for which the model performed poorly.

 Towards a more equitable and sustainable management of global rock phosphate resources

This work highlights that many countries in the world are extremely reliant on mineral phosphorus fertilisers to ensure levels of agricultural productivity. The results raise concerns that agricultural systems may struggle to end their dependence on this non-renewable resource. They also underscore deep inequities in the current distribution of rock phosphate. Countries that adopted intensive agricultural systems very early on, such as those in Western Europe and North America, greatly increased their levels of soil-available phosphorus via the wholesale use of mineral phosphorus fertilisers. These countries must now maintain and enhance this acquired fertility using various strategies, including improved resource recycling. They must also speed up their agroecological transition by implementing a range of mixed crop-livestock farming systems, reducing soil erosion, and utilising urban effluent. In contrast, African countries have historically had little access to mineral phosphorus fertilisers even though their soils are often highly deficient in phosphorus, which limits food and agricultural production. Remaining rock phosphate resources must be fairly distributed, prioritising countries with the greatest need so as to promote global food security.

Alternatives to mineral phosphorus fertilisers

Mineral phosphorus fertilisers have boosted agricultural yields and promoted food security in numerous countries. Unfortunately, they are derived from non-renewable supplies of rock phosphate. In addition, rock phosphate mining and processing causes environmental harm. Certain countries, such as France, have accumulated large quantities of soil-available phosphorus. They must now strive to greatly temper their use of mineral phosphorus fertilisers. The reality is that yields will not necessarily suffer from the absence of fertilisers because crops can draw upon stocks of soil-available phosphorus, depending on soil type. Notably, within crop rotations, species such as white lupin or buckwheat can release phosphorus that is chemically bound to the soil, increasing its availability for other crops. Furthermore, these countries must urgently work to preserve the soil phosphorus fertility they have acquired. Notably, they can limit soil erosion, by using cover crops or reincorporating hedgerows into agricultural landscapes, and improve the recycling of organic matter, including livestock effluent and sludge from sewage treatment plants.


Joséphine Demay, Bruno Ringeval, Sylvain Pellerin, Thomas Nesme. Half of global agricultural soil phosphorus fertility derived from anthropogenic sources. Nature Geoscience. 5 January 2023 DOI: 10.1038/s41561-022-01092-0


Service Presse INRAE

Scientific contacts

Joséphine Demay Joint Research Unit for Atmosphere-Plant-Soil Interactions (UMR ISPA)

Sylvain Pellerin Joint Research Unit for Atmosphere-Plant-Soil Interactions (UMR ISPA)



Learn more

Climate change and risks

The Franco-African research initiative TSARA moves into action

PRESS RELEASE - Nine months after its launch at the Paris International Agricultural Show 2022, the first General Assembly of the TSARA Initiative [1], held on 5 December in Cape Town, South Africa, laid the foundation stone for its implementation with its 19 African and French members from 11 countries and other participants. This meeting, organised by INRAE (French National Research Institute for Agriculture, Food and Environment), CIRAD (French Agricultural Research Centre for International Development) and the Agricultural Research Council (ARC) on the sidelines of the World Science Forum 2022 and attended by high-level delegations, was an opportunity to set up the governance and establish the operational schedule for the international initiative. The ambition of the TSARA initiative is to strengthen cooperation in partnership research to promote sustainable agriculture, food systems and agricultural, pastoral and forest landscapes. This initiative addresses multiple challenges in Africa, Europe and the world, particularly issues around food security, global warming, biodiversity, the health of humans, animals and ecosystems as well as youth employment and gender equality.

[1] Transforming Food and Agricultural Systems through Research in Partnership with Africa.

05 December 2022


Nitrogen: key to going organic

PRESS RELEASE - Easing the transition to agricultural systems that can guarantee a sufficient level of production with-out sacrificing quality or sustainability is a major challenge. The development of agroecology relies on several levers, including organic farming. However, one of the stumbling blocks to going organic is the limited amount of nitrogen in soil, which is essential for plant growth. This reality has never been factored into studies exploring the possibility of meeting global food demand through organic farming. A research team from INRAE and Bordeaux Sciences Agro, the French National School for Agricultural Engineering, has developed a model to simulate, on a global scale, the supply and de-mand of nitrogen in crops for such scenarios, excluding the use of synthetic nitrogen fertilisers. Their findings, published in the 13th of May in Nature Food, shows that the global roll-out of organic farming systems could be stymied by a lack of nitrogen resources. The researchers also showed that, to en-sure sustainability, organic farming must go hand in hand with a re-shuffle of livestock systems, more balanced human diets, and a significant reduction in food waste.

12 May 2021

Climate change and risks

Think global, act local: how to manage dryland grazing in a warming climate

PRESS RELEASE - An international team of more than 130 scientists, coordinated by INRAE, CNRS and the University of Alicante (Spain), has conducted the first global study to assess the impact of grazing on the world's arid ecosystems, where 78% of the world's rangelands are located. Their results, published on 24 November in Science, show that grazing is beneficial in relatively cold climates and in geographical areas with high animal and plant biodiversity. Conversely, these effects become largely detrimental in warmer regions of the world with low biodiversity. The findings of this study can contribute to the development of more sustainable rangeland management, as well as to the establishment of effective management and restoration actions to mitigate the effects of climate change and desertification.

25 November 2022