Republished from Agri-Pulse with permission. May 6, 2026.
By Patrick Serfass
America’s food supply depends on fertilizer. But much of our fertilizer supply is vulnerable to global bottlenecks in foreign nations.
When tensions disrupted traffic through the Strait of Hormuz, fertilizer prices spiked by as much as 40%, adding six figures to many farmers’ annual costs almost overnight. With China’s recent restrictions on fertilizer exports, these costs could rise even higher. These recent spikes come on top of years of pressure on American agriculture: labor shortages, rising input costs and unfair competition from abroad.
Now, fertilizer, often a farmer’s single largest input cost, is becoming even more volatile. And these costs don’t stay on the farm. They show up for all of us on our grocery store receipt.
The same approach the United States has long used to strengthen domestic energy supply can also reduce our reliance on foreign fertilizer. We can turn our organic waste into a valuable, natural fertilizer known as digestate, making good use of the resources we already have here at home.
Digestate is a nutrient-rich fertilizer produced when organic waste such as manure, food scraps, and crop residues is processed in biogas systems. These systems use naturally occurring microbes to break down the waste, generating renewable energy in the form of biogas. What remains is digestate — a liquid and solid material rich in nitrogen, phosphorus, potassium, micronutrients and organic carbon essential for healthy soil. Because the digestion process breaks down complex compounds and significantly reduces pathogens, digestate is stable, safe and readily available for crops to absorb.
Research shows digestate doesn’t just replace conventional, synthetic fertilizers; it can outperform them. A recent Iowa State University study showed that digestate boosts soil organic carbon, which allows plants to absorb more nutrients and helps the soil retain more water, thereby reducing runoff risk and soil loss.
In other studies, sunflower yields increased by as much as 40%, and crop quality improved, including higher levels of proteins and vitamins in tomatoes. Sometimes, that means even an additional harvest in a year.
For farmers, the benefits are not theoretical; they show up in their bank accounts.
Bryan Sievers, an Iowa farmer, grows corn and feeds cattle. Digestate has replaced a significant portion of the synthetic fertilizer he once relied on. “Before digestate, fertilizer was one of our largest expenses,” he explains. “Now we’re saving about $110,000 a year.”
Stories like this are becoming increasingly common. U.S. farmers spend nearly $34 billion annually on fertilizer products. For farms with access to digestate, those input costs can be reduced substantially.
And digestate solves another problem: waste.
Each year the U.S. produces more than 120 million dry tons of farm animal manure, and sends more than 24 million dry tons of inedible food waste to landfills, locking away valuable nutrients that could be redirected to agriculture. Additionally, when left unmanaged, much of that waste releases methane, a greenhouse gas far more potent than carbon dioxide. Anaerobic digestion captures that methane for energy while preserving the nutrients, creating a valuable fertilizer, a true win-win.
The opportunity is enormous. We can turn America’s organic waste into a domestic fertilizer supply at scale. With full deployment, the U.S. biogas industry could produce enough renewable fertilizer to replace all of the synthetic fertilizer American farmers use each year, creating a domestic nutrient supply that would make our nation fertilizer independent, or even a net exporter. The benefits stack up quickly: lower input costs for farmers, new revenue for rural communities, fewer methane emissions and less reliance on the energy-intensive production of synthetic fertilizers.
Biogas systems are valued today for the energy they produce, but digestate is just as important. Biogas systems first turn waste into fuel, then convert what remains into fertilizer that feeds the nation.
Now is the moment for Congress to act. The bipartisan Homegrown Fertilizer Act, introduced by Sens. Roger Marshall, M.D. and Amy Klobuchar, would accelerate the development of domestic fertilizers like digestate. It would help relieve tight fertilizer markets, reduce costs for farmers, put waste to productive use and strengthen America’s agricultural independence.
At a time of rising global uncertainty and growing waste challenges, that’s not just smart policy. It’s how America can take control of its food and fertilizer future.
Patrick Serfass is executive director of the American Biogas Council, an organization which represents more than 400 companies and 6,000 professionals in all parts of the biogas supply chain.