Detection and Analysis -- Secondary Metabolites in Soil Ecology -- Detection of Antibiotics Produced by Soil and Rhizosphere Microbes In Situ -- Rhizosphere Metabolomics: Methods and Applications -- N-Acyl Homoserine Lactone Quorum Sensing in Gram-Negative Rhizobacteria -- Bacterial Metabolites -- The Effect of Bacterial Secondary Metabolites on Bacterial and Fungal Pathogens of Rice -- Secondary Metabolites of Soil Streptomycetes in Biotic Interactions -- Fungal Metabolites -- The Effect of Fungal Secondary Metabolites on Bacterial and Fungal Pathogens -- Biological Significance of Truffle Secondary Metabolites -- Mycotoxins in the Soil Environment -- Plant Metabolites -- Constitutive Secondary Plant Metabolites and Soil Fungi: Defense Against or Facilitation of Diversity -- Root Exudates Modulate Plant—Microbe Interactions in the Rhizosphere -- Functional Aspects -- The Impacts of Selected Natural Plant Chemicals on Terrestrial Invertebrates -- The Role of Soil Microbial Volatile Products in Community Functional Interactions.