Book excerpt: Principles and Practices in Plant Ecology: Allelochemical Interactions provides insights and details recent progress about allelochemical research from the ecosystem standpoint. Research on chemical ecology of allelochemicals in the last three decades has established this field as a mature science that interrelates the research of biologists, weed and crop scientists, agronomists, natural product chemists, microbiologists, ecologists, soil scientists, and plant physiologists and pathologists. This book demonstrates how the influence of allelochemicals on the various components of an ecosystem-including soil microbial ecology, soil nutrients, and physical, chemical, and biological soil factors-may affect growth, distribution, and survival of plant species. Internationally renowned exper†s discuss how a better understanding of allelochemical phenomena can lead to true sustainable agriculture.