Coinoculação com bradyrhizobium e azospirillum associada ao silício no feijão-caupi: revisão de literatura

Abstract

Cowpea productivity in Brazil is still limited by water stress, low soil fertility, inadequate management, and reduced adoption of sustainable technologies. Among emerging strategies, co-inoculation with plant growth-promoting bacteria, especially Bradyrhizobium spp. and Azospirillum ssp., combined with silicon (Si) application, has stood out for its potential to optimize biological nitrogen fixation, improve root development, and increase tolerance to adverse conditions. This study aimed to analyze and gather scientific evidence on the effects of co-inoculation with Bradyrhizobium spp. and Azospirillum spp., associated with silicon application, on the physiological and productive performance of cowpea. This review article synthesizes scientific evidence published between 2021 and 2025 on the effects of co-inoculation and silicon application on the growth, physiology, and productivity of cowpea, including comparisons with related legumes. In general, studies demonstrate that co-inoculation can increase nodulation, biomass accumulation, nutrient absorption, and yield components, 4 especially in stressful environments or those with low nitrogen availability. Silicon, in turn, acts as a beneficial element by reinforcing cell integrity, modulating antioxidant responses, and improving water and photosynthetic efficiency, potentially enhancing microbial effects. Despite advances, gaps remain related to variability among cultivars, environments, and application methods. It is concluded that the integration of co-inoculation and silicon represents a promising and sustainable alternative, but depends on recommendations tailored to cultivation conditions. Keywords: Vigna unguiculata; growth-promoting bacteria; biological nitrogen fixation; silicon; abiotic stresses