Finding fertilizer that pays off for all
Global Futures Laboratory researchers at ASU working to find a more sustainable domestic supply of phosphate, an essential mineral for life
Much of America's phosphate fertilizer supply is produced in other countries. The Sustainable Phosphorus Alliance, housed within the Julie Ann Wrigley Global Futures Laboratory at Arizona State University, is working to bolster phosphorus use, recovery and recycling. Photo by Shutterstock
The U.S. federal government has designated 60 minerals as critical to the economy and national security. Many are used in energy production and advanced manufacturing.
Phosphate — which was added to the list late last year — is one of the few primarily used in agriculture.
Why is phosphate critical? Phosphate is essential to life. It helps grow strong bones and plant roots. More than 85% of the world’s mined phosphate rock is used in fertilizer.
For now, America relies on a finite supply of phosphate that is only mined and refined in a handful of countries, some of which are in active trade disputes with the U.S.
Strong global demand and the war in Iran have increased fertilizer prices, straining farmers that already rely on razor-thin profit margins to stay in business.
What are its drawbacks? When phosphate is overapplied to farm fields, it can run off into lakes and rivers, where it can trigger explosive algae growth, create conditions that kill aquatic life and increase greenhouse gas emissions.
It’s also a common pollutant in wastewater, expelled primarily in urine.
Get involved
National phosphate policy is changing quickly. Watch for the Sustainable Phosphorus Alliance’s Phosphorus Forum in Washington, D.C., this October, where more detailed policy recommendations are expected.
What we’re doing about it: The Sustainable Phosphorus Alliance, housed within the Julie Ann Wrigley Global Futures Laboratory at Arizona State University, is working to bolster phosphorus use, recovery and recycling.
Researchers are also experimenting with ideas to capture the mineral in urine before it is mixed with other waste. They are focusing on how to make this collection profitable, particularly because mined phosphate, despite recent price increases, is still relatively cheap. Part of that involves capturing other valuable substances from wastewater that could be profitably repurposed.
An advanced digester is in development that can break down farm animal waste, wastewater sludge and even food scraps to produce methane, which can be sold as natural gas.
In addition to capturing phosphate, the device can pull carbon, nitrogen and even precious metals such as gold from these streams.
Researchers aim to begin testing the digester at a municipal wastewater treatment center later this year.
This article is part of “Futurecast,” a biannual guide to how the Global Futures Laboratory is solving the most pressing water, power, air, heat and food issues.