The living soil: a bit of what happens in this environment. An emphasis on phytopathogens

Abstract

Soil is an ecosystem with a carbon pool that suports biological diversity. In this review, we present how significant is the symbiosis between the plant root and the macro and microorganisms of the soil, as well as the benefits it generates to achieve an ecological balance and maintain low populations of plant pathogens in food production. For instance, earthworms, collembola, mealybugs and oribatid mites greatly influence the functioning of the soil system, as they build and maintain soil structure and actively participate in nutrient cycling through mineralization and humification processes, in addition to consuming pathogens. On the other hand, microorganisms such as mycorrhizal fungi, which benefit by absorbing the nutrients of the plant and help it absorb minerals from the soil, provide protection to the roots against phytopathogens. Mycorrhizal fungi induce changes in the plant and then the plant responds by producing exudates from the roots that reduce or repel plant pathogens. Another example is the Trichoderma fungus, known as a biocontrol agent for producing secondary metabolites with antimicrobial activity against plant pathogens. Biological control agents and their secondary metabolites are potential approaches currently being used to reduce or replace agrochemicals. Finally, integrated crop management promotes competition and balance essential to maintaining soil health and ensuring food production.