Bacterial Mixtures, the Future Generation of Inoculants for Sustainable Crop Production

Plant growth-promoting bacteria (PGPB) have been extensively studied, because of different mechanisms to perform phytostimulation, as well as the abilities to colonize plants. The number of crop types and hectares of agricultural land, where PGPR are applied is low compared with the total crops or farming area. However, the PGPB application in crop fields is increasingly becoming more accepted due to the advantages to crops and environment such as the increment in productivity, the diminution in the use of chemical fertilizers and toxic compounds such as pesticides and herbicides. These traits make beneficial bacteria formulations the ‘right choice’ in healthy agriculture since they are highly compatible with sustainable crop production. The co-inoculation of plants with two or more beneficial bacteria apparently provides greater phytostimulation than mono-inoculation, perhaps because of the synergistic and multifarious effects occurring when two or more microorganisms are co-interacting. There is a consensus that bacterial mixtures provide greater benefits to the plants, the number of formulations containing more than three species of microorganisms in consortium is still limited. Therefore, we believe that more research and investment is needed to design and formulate multi-species inoculants containing compatible bacteria and other beneficial microorganisms in order to be capable of coexisting both in the designed formulation and associated with plants for sustainable benefits.