The relationships between soils, microbes and humans are of crucial relevance in the tropics, where plant stress and microbial activity are exacerbated. This volume of Soil Biology presents the living component of tropical soils, showing how it is shaped by environmental conditions and emphasizing its dramatic impact on human survival and well-being. Following an introduction to the specificities of tropical soils and of their microbial communities, the biological aspects of soil management are examined, dealing with land use change, conservation and slash-and-burn agriculture, the restoration of hot deserts, agroforestry and paddy rice cultivation. As they are of particular relevance for tropical agriculture, symbioses of plants and microbes are thoroughly covered, as are the biodegradation of pesticides and health risks associated with wastewater irrigation. Lastly, traditional soil knowledge is discussed as a key to our sustainable presence in this world.