Risk of fertiliser cartels controlling world's food supply by 2050, says study

An international cartel which controls the majority of the world's supply of crucial fertiliser nutrients could create "political challenges and uncertainties" warn scientists, who say depleting levels of nutrients in the earth's soil are putting global food security at risk.

In a review paper published today in the journal Science, top soil scientists warn that farming has massively contributed to soil erosion, with nutrients depleting faster than they can be replenished.

With the ability of the earth's soil to maintain the growth of the world's food supply plateauing, the authors suggest the industrial revolution led to a huge growth in agriculture which then accelerated the depletion of nutrients in the soil.

"Ever since humans developed agriculture, we've been transforming the planet and throwing the soil's nutrient cycle out of balance," said the paper's lead author Professor Ronald Amundson from the University of California, Berkeley. "Because the changes happen slowly, often taking two to three generations to be noticed, people are not cognizant of the geological transformation taking place."

One of the key threats to the future of the global food security is the supply of key nutrients which are used as fertilizers, two of which are potassium and phosphorus. The authors point out that these nutrients are mined from rocks and not distributed equally around the world, a situation which could leave the fate of the world's food supply in the hands just a few countries.

"Morocco will soon be the largest source of phosphorus in the world, followed by China, " Professor Amundson said. "These two countries will have a great deal of say in the distribution of those resources. Some people suggest we will see the emergence of a phosphorous cartel."

The report highlights the dwindling supply of phosphorus in the US, adding that the country's reserves will likely run out within three decades. "The most productive mine in the United States will be depleted in 20 years, which will force it to become increasingly reliant on imports to sustain its agricultural and industrial sectors." It also points out the US has only 1% or 2% of the world's potassium reserves.

The authors argue for better nutrient management techniques to preserve supplies. Recycling nutrients which are currently discarded in certain processes, such as wastewater treatment, is one example according to Professor Amundsen.

"We should be able to do this with soil," he said. "The nutrients lost can be captured, recycled and put back into the ground. We have the skillset to recycle a lot of nutrients, but the ultimate deciders are the people who create policy. It's not a scientific problem. It's a societal problem."

Martin Lukas, an associate professor at the school of agriculture at Reading University agrees that the recycling of waste water is a sensible idea, but adds that nutrient depletion is not an imminent problem. "We are talking decades here, in which case most of the time as soon as we have a big problem we find a technological way around it," he says.

"This capacity of soil to support plant growth isn't just going to run out one day. If they stop supplying nutrients they would still be able to grow crops, it's just that the yield would be lower," he adds.

The UN has declared 2015 the International Year of Soils, with a program to raise awareness of soil depletion and to promote soil preservation.