Researchers cut fertilizer use and emissions
Rice feeds more than half the world but its production creates heavy economic and environmental costs. New field research led by the University of Massachusetts Amherst and China’s Jiangnan University demonstrates that applying nanoscale selenium directly to rice plants can change this.
Using drones, scientists lightly sprayed a selenium suspension on rice foliage and stems. This direct contact helped plants absorb the element efficiently, raising photosynthesis by over 40 percent. The improved photosynthesis allowed plants to pull in more carbon dioxide and send extra carbohydrates to the roots, encouraging stronger root growth and beneficial soil microbes.
These microbes helped rice absorb nitrogen better, lifting nitrogen use efficiency from 30 percent to 48.3 percent. Farmers could reduce nitrogen fertilizer use by 30 percent while maintaining high yields and cutting emissions of methane, ammonia, and nitrous oxide by up to 45.6 percent. Nitrogen fertilizer manufacturing is also energy intensive, so using less lowers overall greenhouse gas emissions.
The grain itself gained higher protein, important amino acids, and selenium levels, improving nutrition. Economic returns rose by over 38 percent per ton of rice compared with conventional methods.
“Everybody knows that we need to improve nitrogen use efficiency,” said Baoshan Xing, University Distinguished Professor at UMass Amherst. “We used an aerial drone to lightly spray rice growing in a paddy with the suspension of nanoscale selenium,” said Wang. “That direct contact means that the rice plant is far more efficient at absorbing the selenium than it would be if we applied it to the soil.”
Since rice farming accounts for about 15–20 percent of global nitrogen use, this nano selenium method offers a practical way to feed a growing population while reducing climate impacts and costs.
Photo Credit: istock-digitalsoul