Soil Diseases Suppressiveness Conferred by Organic Farming, Practices and Microbial Metabolites

ABSTRACT A major obstacle to the creation of efficient biobased disease management practices continues to be the poor integration of traditional agricultural practices and cutting-edge technical approaches. The present review will expand the understanding of organic amendments and metabolites-mediated microbial community metabolism and their mechanistic aspects in disease-suppressive soil (DSS). Organic amendments have been shown to promote the biocontrol potential of resident soil microbiota. Organic amendments positively affect the labile carbon, cation exchange content (CEC) and microbial enzymatic activity. DSS is considered a rich source of beneficial soil microbial community that produces a plethora of antibacterial metabolites. Multiple gene clusters associated with known metabolites offer mechanistic insights associated with disease-suppressive phenotypes. Organic amended soil has higher abundance of chemotaxis genes. Several strains of Bacillus and Pseudomonas produce key metabolites, phenazines, 2,4-diacetylphloroglucinol, pyoluteorin, pyrrolnitrin, cyclic lipopeptides and volatile organic compounds in DSS. High-resolution metagenomics combined with bioinformatics tools would be instrumental in the identification of biomarkers associated with suppressive soils. The integration of traditional and genomic approaches can be employed to infer the untapped potential of resident soil microbiomes.