Scientists found that spraying rice with nanoscale selenium boosts yields, improves nutrition, reduces fertilizer use by 30%, and cuts greenhouse gas emissions — a breakthrough for sustainable farming and global food security.
Rice is the daily staple for more than 3.5 billion people. But growing it comes at a steep cost: rice paddies demand enormous amounts of fertilizer, consume vast resources, and generate significant greenhouse gas emissions. Now, scientists may have found a surprisingly simple way to make rice farming more sustainable — using tiny doses of nanoscale selenium.
Researchers from the University of Massachusetts Amherst and Jiangnan University in China report that spraying rice plants with nanoscale selenium dramatically improved fertilizer efficiency, boosted crop yields, enhanced nutrition, and cut harmful emissions. Their findings, published in the Proceedings of the National Academy of Sciences (PNAS), demonstrate that this method works not just in the lab, but in real-world field conditions.
The Fertilizer Problem
Modern agriculture has long relied on nitrogen-rich fertilizers, a key driver of the Green Revolution. But they’re costly, carbon-intensive to manufacture, and highly inefficient. Rice, in particular, absorbs only about 30% of applied nitrogen, meaning most fertilizer washes away into waterways, creating dead zones and fueling climate change through the release of methane, ammonia, and nitrous oxide.
“Everybody knows we need to improve nitrogen efficiency — the question is how,” said Baoshan Xing, University Distinguished Professor of Environmental and Soil Chemistry at UMass Amherst and co-senior author of the study.
A Nano Solution
The team discovered that applying nanoscale selenium directly to rice plants — using drones to lightly spray stems and leaves — allowed the crops to absorb and use nitrogen far more effectively.
Selenium stimulated photosynthesis by over 40%, helping plants pull in more carbon dioxide and convert it into carbohydrates. These sugars then nourished stronger roots, which released compounds that fostered beneficial soil microbes. In turn, the microbes helped rice roots capture more nitrogen, increasing nitrogen use efficiency from 30% to nearly 50%.
This shift not only reduced fertilizer waste but also cut emissions of nitrous oxide and ammonia by up to 45%.
More Yield, More Nutrition
Healthier plants also produced higher yields and more nutritious grains. Protein, essential amino acids, and selenium content all rose, giving rice a stronger nutritional profile. Farmers, meanwhile, could cut fertilizer use by 30%, improving profits while reducing environmental harm.
According to the researchers, this technique boosted the economic benefit of rice farming by 38% per ton, while reducing negative environmental impacts by 41%.
Feeding the Future
Since rice production accounts for as much as 20% of the world’s nitrogen use, even partial adoption of this approach could significantly lower agriculture’s carbon footprint while feeding a growing population.
“The Green Revolution gave us food security but also left us with new challenges,” said Xing. “This nanoscale approach could help us spark the next revolution — one that’s more sustainable.”