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.