Inoculants or biofertilizers aiming to partially or fully replace chemical fertilizers are becoming increasingly important in agriculture, as there is a global perception of the need to increase sustainability. In this review, we discuss some important results of inoculation of a variety of crops with rhizobia and other plant growth-promoting bacteria (PGPB). Important improvements in the quality of the inoculants and on the release of new strains and formulations have been achieved. However, agriculture will continue to demand chemical pesticides, and their low compatibility with inoculants, especially when applied to seeds, represents a major limitation to the success of inoculation. The differences in the compatibility between pesticides and inoculants depend on their active principle, formulation, time of application, and period of contact with living microorganisms; however, in general they have a high impact on cell survival and metabolism, affecting the microbial contribution to plant growth. New strategies to solve the incompatibility between pesticides and inoculants are needed, as those that have been proposed to date are still very modest in terms of demand.

Soil microorganisms play an important role on plant development and the homogenization of soil microbiomes is harmful to agri-environments. It is essential that agricultural practices are carried out by taking soil microbiome preservation in consideration. Agroforestry systems are one of the most environmentally friendly agrosystems and its plant diversity directly influences the soil microbiome diversity. In this study, we tested the efficacy of the microbial consortium (MC) obtained from compost and the cyanobacteria Arthrospira platensis (Ap) compared with the application of the vermicompost tea (VT) and bokashi (Bk) in arugula, lettuce, beetroot, and carrot in two seasons in a recently implemented agroforestry system. We aimed to verify if MC and Ap could be new promising sustainable alternatives in vegetables production. The strategy can be broken down into three stages: (1) Green manure management: planting, cutting, griding, and incorporation in the soil, (2) agroforestry system implementation, and (3) treatment application in a completely randomized blocks design. The vegetables yield was measured. Nutritional traits and the plant root system were evaluated for arugula and lettuce. Greater plant yield, nutritional values, and plant root development were observed in the MC-treated plants; Ap and Bk had, in general, similar results. Our data show that both MC and Ap have potential to become a sustainable product for agricultural production.