RUDN University Biologists: Nanosilver Increases Soybean Yield

RUDN biologists have shown that silver nanoparticles increase the yield of soybeans. The key to that is in the symbiosis of soy and rhizobia bacteria. The results are published in Agronomy.

The yield of soybean depends not only on the quality of the soil and climatic conditions. In many ways, it is determined by the effectiveness of the symbiosis of soybean and rhizobia bacteria (Rhizobium ). These bacteria “infect” the plant, but do not harm it. When they attach to the roots of a plant, they begin to “trap” nitrogen from the soil. This is beneficial for the plant, since nitrogen is an essential element for the growth and formation of tubers. This symbiosis is called mycorrhiza. It gives agronomists another opportunity to increase soybean yields. To do this, you need to learn how to influence mycorrhiza.

“Soybean is one of the most important crops and interest in its cultivation is growing due to the growing demand for vegetable protein raw materials. Soybean yield is largely determined by rhizobia. Therefore, the problem arises to find regulators that affect not only the growth and vital activity of the plant, but also symbiotic processes. Silver nanoparticles have unique biological effects and are considered new plant growth stimulants. They help increase biomass, stimulate germination and further growth of fruits,” said Meisam Zargar, PhD, Associate Professor of the Agro-Biotechnological Department of RUDN University.

Biologists used an aqueous solution of silver nitrate, from which they made nanoparticles. The resulting particles were used for the treatment of chernozem soil in the Krasnodar Region (Russia). Part of the soil was additionally treated with different types of fertilizers. Soybean seeds were sown in the prepared soil, which were also treated with silver nanoparticles before. The experiment lasted two years.

The results of a long-term experiment showed that low doses of silver nanoparticles significantly increased the number of root nodules and increased soybean yield. RUDN biologists explained the effectiveness of the action by the fact that in the terrestrial, “uninfected” part of the plant, the activity of two enzymes increases – peroxidase and polyphenol oxidase. They prevent the penetration of rhizobia. At the same time, in the roots of the plant, which are susceptible to rhizobia, the activity of peroxidase and polyphenol oxidase increases. This leads to a more active formation of tubers and the development of symbiosis.

“Low doses of silver nanoparticles increase the intensity of legume-rhizobium symbiosis. This increases soybean yields. The effect may be associated with the activation of plant signaling systems,” said Meisam Zargar, PhD, Associate Professor of the Agro-Biotechnological Department of RUDN University.