Maize is an important commodity produced and consumed as a food and a beverage in various parts of the world. Brazilian maize production ranks third highest in the world. The high costs of cultivation, in terms of fertilizers, can be obstacles to the small farmer and suggests that simpler strategies are needed. Brazil is one of the highest beer-consuming countries. Beer production generates a significant number of by-products rich in functional nutrients that can be used in agriculture. This work aimed to investigate the development of hybrid maize AG1051, planted in soil enriched with barley malt bagasse (BMB), generated from the industrial production of craft beer. BMB samples 2.5; 5.0 and 10.0% (w/w) were tested in a soil free of NPK fertilizer. Two controls were tested: soil samples with the addition of only NPK 10/10/10; and soil samples not supplemented with BMB. After 50 days the treatment of the samples with BMB by > 5% significantly improved the development of the maize, in terms of height, dry mass of the stem and roots, diameter of the stem, and number of viable leaves. On the other hand, there could be no correlation between microbiota growth and enhanced plant biomass because the BMB stimulated total cultivable heterotrophic bacteria similarly in all tested groups, suggesting that the essential nutrients for maize development were bioavailable as much with the barley mass bagasse as they would be from microbial degradation. BMB is then suggested as a low-cost alternative to NPK fertilizers for subsistence agriculture.