Rice is the daily staple for more than 3.5 billion people around the world, but producing it comes with huge costs to the environment, climate, and economy.
Growing rice requires heavy use of nitrogen-rich fertilizers, which are expensive, wasteful, and major contributors to pollution and greenhouse gas emissions.
Now, a breakthrough study led by scientists at the University of Massachusetts Amherst and Jiangnan University in China may point to a more sustainable future for rice farming.
The researchers found that applying nanoscale selenium—a mineral essential for both plants and humans—can make rice farming more efficient and nutritious.
Their study, published in the Proceedings of the National Academy of Sciences, is the first to show that this approach works outside of the lab under real-world conditions.
During the Green Revolution of the mid-20th century, synthetic fertilizers fueled dramatic increases in crop yields.
But that progress has reached its limits. Fertilizers are costly to produce, release large amounts of carbon dioxide, and often don’t stay where they’re needed.
Rice plants, in particular, use only about 30% of the nitrogen applied to them, meaning that most fertilizer washes away into rivers and oceans, where it creates dead zones and other ecological problems.
What’s left in the soil produces methane, ammonia, and nitrous oxide—potent greenhouse gases that worsen climate change.
“Everybody knows we need to improve nitrogen use efficiency,” said Baoshan Xing, a co-senior author of the study. “The question is how?”
The team’s answer was nanoscale selenium. Instead of applying it to the soil, where most nutrients are wasted, they sprayed it directly onto the rice plants using drones.
This method allowed the plants to absorb selenium much more effectively.
The results were dramatic: photosynthesis increased by more than 40%, which helped the plants capture more carbon dioxide and turn it into energy for growth. Stronger roots then released compounds that fed beneficial microbes in the soil.
These microbes worked with the plants to draw in more nitrogen, boosting nitrogen use efficiency from 30% to 48.3%.
This approach not only reduced the release of harmful gases by up to 45% but also made the rice itself healthier.
Grains contained more protein, key amino acids, and selenium, making them more nutritious for human diets. At the same time, yields stayed high even with 30% less fertilizer.
According to the researchers, this method could cut the negative environmental impacts of rice cultivation by 41% while increasing farmers’ profits by over a third per ton of rice.
Since rice farming accounts for up to 20% of global fertilizer use, this discovery could have sweeping benefits for food security, climate change, and agricultural sustainability.
As Xing noted, “We need a new kind of agricultural revolution, and nanoscale selenium could be part of the solution.”
