The textbook "Secondary Metabolites in Soil Ecology" offers a comprehensive analysis of the role of secondary metabolites produced by bacteria, fungi, and plants in soil ecosystems. Despite the known structural diversity and pharmacologically relevant activities of these compounds, our understanding of their biological functions remains limited. This volume examines the functional aspects of secondary metabolite production, focusing on the interactions between soil organisms. The topics covered range from truffle metabolites and the phenomenon of combustion to the ecology of mycotoxins in soil, as well as root exudates and chemical interactions between Streptomyces and mycorrhizal fungi. Additionally, the role of microbial metabolites as quorum-sensing signals, their protection of plants against pathogens, and the effects of volatile compounds on soil invertebrates are discussed. Techniques for detecting antibiotics in soil and the application of metabolomics in rhizosphere research, which has made significant progress in recent years, complete the book.