Nitrogen is essential for plant growth, but manufacturing synthetic fertilizer is energy-intensive and expensive. Hungria focused on biological nitrogen fixation, a process where microbes convert nitrogen from the air into forms plants can use. She studied rhizobia, bacteria that live in nodules on legume roots, and showed that inoculating soybean seeds annually could raise yields by up to 8 percent compared to synthetic fertilizer alone.
Over four decades at the Brazilian Agricultural Research Corporation, known as Embrapa, she helped scale these treatments nationwide. Today, her microbial inoculants are used on more than 99 million acres (40 million hectares) of farmland in Brazil. The impact is enormous. Farmers save an estimated $25 billion per year in input costs, and the shift away from chemical fertilizers avoids more than 230 million metric tons of carbon dioxide equivalent emissions annually.
She also pioneered commercial strains of Azospirillum brasilense, bacteria that improve nitrogen uptake and stimulate plant growth. Combining these microbes has doubled yield gains in some soybeans and common beans. Her latest work restores degraded pastureland, increasing grass biomass by 22 percent to support cattle production.
When Hungria began her career, few believed microbes could compete with industrial fertilizers. Today, Brazil’s soybean production has grown from 15 million tons in 1979 to a projected 173 million tons in the upcoming harvest.
Her work shows that feeding the world does not have to mean exhausting it. Sometimes, the smallest organisms can drive the biggest revolutions.
"Dr Mariangela Hungria Named 2025 World Food Prize Laureate." FarmingFirst, 2025.
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Another view
Industrial agriculture relies, among other things, on the use of nitrogen fertilizers to maintain high crop yields. Although nitrogen is the most abundant element in the atmosphere, plants are not able to take it and use it for growth.
Industrial agriculture relies, among other things, on the use of nitrogen fertilizers to maintain high crop yields. Although nitrogen is the most abundant element in the atmosphere, plants are not able to take it and use it for growth. However, in nature some bacteria do have the ability to take nitrogen from the air and use it to grow thanks to an enzyme called nitrogenase. If we could get plants producing a functional nitrogenase enzyme, we could obtain crops that do not depend so much on nitrogen fertilizers. The overuse of these chemicals entails environmental problems such as the pollution episodes that have occurred recently in the Mar Menor (Murcia, Spain) or the more frequent events of algal blooms in California (US).
The NifB protein of nitrogen-fixing bacteria is responsible for producing a cofactor, in this case a metal compound, which is essential for the function of nitrogenase. Therefore, obtaining an active NifB protein in plants is critical to achieve crops that are independent of nitrogen fertilizers.
In the work developed by the Biochemistry of Nitrogen Fixation group of the CBGP, tobacco plants, a model organism in plant biotechnology, have been used to produce 30 NifB proteins from different microorganisms to select the candidates that presented the best behavior, i.e., stable and soluble in plant cells. Once this selection had been made, the chosen candidates were isolated from plants and the activity to produce this metal cofactor was studied in the lab. All chosen cadidates proved to be functional in producing this metal compound. These results bring us closer to obtain a functional nitrogenase in plants, reducing fertilizer inputs with the consequent economic and environmental benefits.
