Manufacturing and quality control of inoculants from the paradigm of circular agriculture

Abstract

The use of beneficial rhizosphere microorganisms is part of a “new green revolution” for increasing crop productivity without environmental damage in accordance with the new paradigm of the circular agriculture and bioeconomy that includes either organic or sustainable agriculture which is a reality in several countries. This review analyzes several types of bio-inputs with emphasis on inoculants containing either single or a mixture of beneficial microorganisms such as rhizobia, plant growth-promoting rhizobacteria, or mycorrhizal fungi. Inoculants help in achieving greater harvests by using available microbial resources whose physiological activities or mechanisms may prevent significant losses due to pest and disease incidence. Multiple beneficial mechanisms are considered for isolating functional and beneficial microorganisms from soils and plant tissues. Thus, several methodological steps are involved for developing effective microbial inoculants based on achieving consistent results under field conditions. The survival and maintenance of the microbial activity of inoculants in both rhizosphere and non-rhizosphere soils is critical for the success of any inoculation protocol. This chapter pointed out the need to integrate plant breeding programs, which include the selection of elite microbial strains to enhance inoculant performance. In addition, an extensive revision was made on types of formulations and quality control of inoculants which are determinants to define both strain survival and their effects under field conditions. Experiences of use, regulations, and legislations for inoculants in Latin America are also described. Overall, the perspectives about the use of inoculants are directly linked to reach sustainable agroecosystems.