Outstanding impact of Azospirillum brasilense strains Ab-V5 and Ab-V6 on the Brazilian agriculture: Lessons that farmers are receptive to adopt new microbial inoculants

ABSTRACT For decades, researchers around the world search for strategies aiming at higher sustainability in agriculture. The microbial inoculants or biofertilizers are biotechnological products used different purposes, main one being to totally partially replace chemical fertilizers, with an emphasis on N-fertilizers, reducing costs of production and decreasing contamination soil, water, atmosphere. Depending microorganism inoculated crop, can also induce plant protection abiotic biotic stresses positively modify their physiology. Although inoculation studies use by farmers date more than a century ago, they have gained notoriety past decade. Brazil has long tradition rhizobial inoculants, especially soybean but it was only 2009 that first commercial inoculant carrying plant-growth-promoting Azospirillum brasilense strains Ab-V5 (=CNPSo 2083) Ab-V6 2084), identified our research group, reached market. One decade after release these two strains, 10.5 million doses were commercialized grasses, including corn, wheat, rice, pastures brachiarias, co-inoculation legumes, such as common bean. Several groups presented impressive results increases root growth, biomass production, grain yield, uptake nutrients increased tolerance due Ab-V6. In this review, we gathered obtained so far several grasses legume crops, confirming versatility indicating convincing, reliable, consistent results, Brazilian receptive adoption new sustainable technologies based microorganisms.