AgroPages-Use of groups of microorganisms is new frontier in bioinputs-Agricultural news

Based on a comprehensive literature review, researchers report that the use of microbial consortia offers significant benefits for plant growth, surpassing traditional inoculation methods with single species. Recent studies have revealed that the combination of microorganisms like Bradyrhizobium and Pseudomonas oryzihabitans increased soybean yield by 11% in comparison with individually treated plants. The approach also promoted more robust root growth and better nutrient accumulation.

Moreover, as the researcher at the Federal University of Lavras (UFLA) Peterson Nunes explains, consortia involving four mycorrhizal fungi (Funneliformis constrictum, F. mosseae, Gigaspora margarita and Rhizophagus irregularis) and the fungus Beauveria bassiana (pictured on the right), found in the soil, significantly improved cotton growth. Those combinations not only increased protein and carbohydrate contents in plants, but they also reduced the growth of a pest, the caterpillar Spodoptera littoralis.

The synergy between different strains of Beauveria resulted in 100% mortality of another pest, the moth Plutella xylostella. By the same token, a consortium of two strains of B. bassiana showed higher efficienct against Duponchelia fovealis caterpillar larvae.

Additional studies indicates that microbial consortia can be effective in mitigating abiotic stresses, including those caused by heavy metals, water deficit and soil salinization.

For the Embrapa Environment analyst Gabriel Mascarin, beneficial microbes play a crucial role in modern agriculture, acting as biopesticides, biostimulants and biofertilizers. They also contribute to the health and sustainability of crops, aligning with the principles of regenerative agriculture.

The use of microbial consortia is gaining recognition due to their many potential advantages, such as their stability under different environmental conditions and reduced application costs. The approach also increases microbial biodiversity in plants' rhizosphere and phyllosphere (which refer to the environments near the plant roots and above the ground, respectively), contributing to a more balanced ecosystem.

Recent studies have indicated that microbial consortia can even help to reduce traces of pesticides. A consortium of Aspergillus versicolor and bacteria that had been isolated from sewage sludge showed higher efficiency in the degradation of carbendazim and thiamethoxam molecules. Likewise, a consortium made of Pseudomonas plecoglossicida and two Pseudomonas aeruginosa isolates degraded organophosphate insecticides more efficiently than when they were individually applied.

The combination of different microorganisms also demonstrate benefits in controlling plant diseases and promoting growth. In tests with chickpeas, the combination of Purpureocillium lilacinum and Rhizobium sp. provided superior protection against the nematode Meloidogyne javanica and promoted vigorous plant growth.

In Brazil, a global leader in the production and use of biological control agents, over 70 million hectares were treated with biopesticides in 2022. The growing supply of biological products containing multiple species or strains highlights the importance and potential of microbial consortia in agriculture, according to the Embrapa researcher Wagner Bettiol.

″Those advances point to a future in which precision agriculture and holistic plant health management become increasingly more viable,″ Nunes believes. ″In addition", the researcher underscores, "microbial consortia offer a sustainable solution for resilience to climate change, improved nutrient cycling and reduced environmental impact in agriculture. As the technology evolves, it is expected to play an increasingly important role in sustainable agricultural production".

Out of the 480 biopesticides registered for use in Brazil in 2023, 83 were made with microorganism combinations.