Cover crops as a vehicle for soil application of bio-inputs based on Azospirillum brasilense and Bacillus amyloliquefaciens

Abstract

The adoption of cover crops and bio-inputs is a promising strategy for more sustainable agricultural systems. This study aimed to evaluate the physiological performance of three winter cover crops: white oats (Avena sativa L.), vetch (Vicia sativa L.), and turnip rape (Raphanus sativus L.), inoculated with Azospirillum brasilense and Bacillus amyloliquefaciens, applied individually and in combination, in different doses via seed treatment. The assessments included germination, vigor, and root system development variables, evaluated using a germination test and an image capture and interpretation scanner. The results showed that the response to inoculation varied according to the crops species tested. In white oats, the application of A. brasilense, alone or in a mixture, stood out for promoting greater seedling growth and root development. For vetch, the best results were obtained with isolated inoculation of A. brasilense, with significant increases in germination, vigor, and root system characteristics. In turnip rape, the combination of microorganisms performed satisfactorily, with no negative effects on initial development, while the highest doses of both microorganisms, applied alone, reduced germination and root growth. Considering the set of physiological responses, the capacity to retain grout and the tolerance to inoculant doses, white oats are the most suitable species as a vehicle for soil inoculation of the microorganisms tested.