Abstract The use of amendments in combination with Bacillus subtilis has been understudied as a strategy for rehabilitating acid soils and improving cropping systems. This study aimed to evaluate the effects of amendments and B. subtilis on the development, yield, and nutritional quality of the hard yellow maize Marginal 28 T variety. A randomized complete block design with a factorial arrangement was employed, considering five amendments, including biochar, alongside the application of B. subtilis.