Soil is a complex and dynamic system in constant change due to its natural
processes, as well as interaction among physical, chemical and biological
characteristics that take part in it. However, the greatest transformation occurred due to
the farm business and the adopted management system. Thus, man can manipulate
some soil characteristics and make it more suitable for cropping development.
Although anthropic action cannot fully control how soil characteristics interact, it is
possible to track them. The action of chemical substances should not be disregarded, a
product of the secondary metabolism of plants, since they interfere with plant's ability
to compete and survive. Such substances can act out as protectors against herbivores
and pathogens. They can be attractive or repellent agents in plant-plant competition and
plant-microorganism symbiosis. They can also influence the interaction between plant
matter and soil organisms. Among these substances, terpenoids are highlighted as the
most structurally diverse chemical family in the class of secondary metabolites that are
part of natural products. This knowledge allows a better understanding of nutrient
decomposition and cycling processes, the influence of environmental factors on
production and terpenoid variability in some plants with medicinal and economic
importance.
Keywords: Allelochemicals in Soil, Ecological Interactions in Soil, Secondary Metabolism.
