Effect of the Application of Seaweed and Fishing Industry Derivatives on the Soil Microbial Community and Performance of Common Bean Plants

The rhizosphere microbiome plays a key role in plant nutrition, development, and productivity and is strongly influenced by soil management practices. This study evaluated increasing rates of a marine-derived organo-mineral fertilizer based on seaweed and fishing industry derivatives (0, 1.4, 2.8, and 4.2 g pot−1) on plant gas exchange, yield components, rhizosphere bacterial community structure, and predicted microbial functions in common bean (Phaseolus vulgaris L.) under greenhouse conditions. Fertilization did not significantly affect plant gas exchange (p > 0.05), whereas the highest mean values for yield components were observed at 2.8 g pot−1. Organo-mineral fertilization significantly altered rhizosphere bacterial community structure (PERMANOVA, p < 0.001) and Shannon diversity, whereas estimated richness (Chao1) was not significantly affected. Treatment-associated shifts in bacterial genera and predicted metabolic pathways were detected, particularly at the highest fertilizer rate, but none remained significant after FDR correction. Overall, marine-derived organo-mineral fertilization was associated with changes in common bean yield components and rhizosphere bacterial community structure, without detectable effects on gas exchange at the vegetative stage. These findings demonstrate the potential of marine-derived organo-mineral fertilization to simultaneously influence crop performance and rhizosphere bacterial communities, supporting its application as an input for integrated nutrient management in common bean production.