Unchanged use of Phosphorus in Agriculture threatens food security and environment

Business-as-usual in the Phosphorus supply chain in the next thirty years will affect regional food security and lead to alarming rates of pollution and greenhouse gas emissions associated with the phosphorus supply.  This is shown in a new study published in the journal of Global Food Security, undertaken at University of Iceland, Stockholm University, and the Blekinge Institute of Technology, Sweden. Furthermore, the world regions with high population growth rates are also the regions with the highest deficit in phosphorus supply in the coming decades.

Phosphorus is essential in agriculture to maintain higher production levels, where it is applied as a fertilizer.  Almost all of our phosphate fertilizers come from the mining and processing of phosphate rock and only a handful of countries produce and export this mineral; Morocco and countries surrounding the Sahara Desert. It is estimated that there are around 53 million tons of phosphate fertiliser used in food production which requires 270 million tons of phosphate rock. At the same time, global population growth is expected to push food demand up by more than 50% to 2050, particularly in Latin America and the Caribbean, South Asia and Sub-Saharan Africa. 

Losses along the Phosphorus supply chain have been estimated in the literature at around 80-90%, with serious environmental consequences.  One effect is the overproduction of nutrients in water and the formation of dead zones in the ocean, where no life can be sustained.  To compound the issue phosphate production uses large amounts of energy and water, and produces a toxic and radioactive byproduct known as phosphogypsum. 

Imperative to use sustainable methods in agriculture

“Most of the focus in the literature has been on the sufficiency of the global phosphorus reserves.  However, demand for phosphorus is unequal across regions so it was important to assess which regions require more phosphorus and what will that mean in terms of food security," says Claudiu Eduard Nedelciu, researcher at the Earth Sciences Institute and main author of the study.  His co-authors are Kristín Vala Ragnarsdóttir, professor at the University of Iceland Faculty of Earth Sciences, Peter Schlyter, professor at Blekinge Technology Institute, and Ingrid Stjernquist, research scientist at Stockholm University. The study is a part of of a larger European research project, Adaptation to a new Economic Reality which aims to create a new global economic model and train a new generation of scientists in multi-disciplinary sustainability research.  

Eduard, furthermore, points out that another valuable contribution of this study is that they quantified the negative environmental and climate impacts of the phosphorus supply chain at global and regional level.  "Our results indicate yet again the necessity of closing the loop when it comes to phosphorus and on reducing its usage through more sustainable farming practices,” adds Eduard.

Poorer nations must be supplied

The results of the study indicate that the largest increase in the use of phosphorus in coming decades will be in Latin-America, South-Asia and East and South-east Asia. Large increases are not anticipated Sub-Saharan Africa, despite this being the region with the largest population increase.  This is because historically this region has not used fertilizer extensively, however, this does raise questions concerning food safety since this is the area with the largest number of people suffering from malnutrition. The researchers have pointed out that all the areas where the use of phosphorus will increase the most are dependent on importing the chemical, and thus sensitive to fluctuations in prices and supply.  “Hunger will increase in the parts of the world where phosphorous is lacking, unless actions are taken by governments and international institutions to secure imports”, aid Prof. Kristin Vala Ragnasdottir from the University of Iceland, who lead the AdaptEcon project and is co-author in the study.

The scientists say that the most alarming results are the serious effects of the supply chain of phosphorus on the environment and climate.  The amount of Phosophorus reaching water bodies will more than triple in North Africa and Western Asia until 2050 and will double in South Asia and Latin America and the Caribbean.  If nothing is done to curb the emission of phosphorus from sewage and agricultural areas the overproduction of nutrients will threaten coasts, lakes and water supplies in the coming decades.  “Not only the efficient use of Phosphorous in agriculture but wise management of Phosphorus resources along the supply chain, including environmental effects, will be major challenges for the coming decades” said Prof. Peter Schlyter of the Blekinge Technology Institute and co-author in the study. 

The impact of this important nutrient on the environment is not only the potential pollution of water, but also due to factors involved in the mining of the substance.

According to the calculations of the scientists the impact of phosphorus production on the climate will double between the years 2000 and 2050, if no action is taken . Furthermore around 500 million tonnes of phosophogypsum will need to be disposed of annually, if no technology is developed to recycle that toxin.

This means that it is imperative to take a holistic view at the phosphate supply chain in food production to realise the issues we face. Understanding the problem may help to further some of the United Nation's UN Sustainable Development Goals. 

Further information on the study.