Successful agroforestry requires an understanding of the complex relationship between trees, crops and soils. This book provides a review of both social and biophysical aspects of soil use and research in agroforestry in the tropics, with an emphasis on nutrient-poor forest and savanna soils. Key topics covered include decomposition, nutrient cycling and leaching, soil structure, and soil biological processes. The book combines theory and a review of methods used in research.