Wheat That Makes Its Own Fertilizer May Reduce Pollution, Offer Lower Costs for Farmers

By Trina Kleist

Scientists at the University of California, Davis, have developed wheat plants that stimulate the production of their own fertilizer, opening the path toward less air and water pollution worldwide and lower costs for farmers.

The technology was pioneered by a team led by Eduardo Blumwald, a distinguished professor in the Department of Plant Sciences. The team used the gene-editing tool CRISPR to get wheat plants to produce more of one of their own naturally occurring chemicals. When the plant releases the excess chemical into the soil, the chemical helps certain bacteria in the soil convert nitrogen from the air into a form the nearby plants can use to grow. That conversion process is called nitrogen fixation.

In developing countries, the breakthrough could be a boon for food security. The study was published in the Plant Biotechnology Journal.

"In Africa, people don't use fertilizers because they don't have money, and farms are small, not larger than six to eight acres," Blumwald said. "Imagine, you are planting crops that stimulate bacteria in the soil to create the fertilizer that the crops need, naturally. Wow! That's a big difference!"

The breakthrough in wheat builds on the team's earlier work in rice. Research is also underway to extend this technology to other cereals.

Worldwide, wheat is the No. 2 cereal crop by yield and takes the biggest share of nitrogen fertilizer, using about 18% of the total. Globally, more than 800 million tons of fertilizer were produced in 2020 alone, according to figures from the United Nations Food and Agriculture Organization.

But plants take up only about 30 to 50% of the nitrogen in fertilizer. Much of what they don't use flows into waterways, which can create "dead zones" that lack oxygen, suffocating fish and other aquatic life. Some excess nitrogen in the soil produces nitrous oxide, a potent climate-warming gas.