This college-level textbook summarizes the state of current knowledge in the rapidly expanding field of agroforestry. The book, organized into 25 chapters in six sections, reviews the developments in agroforestry during the past 15 years and describes the accomplishments in the application of biophysical (plant and soil related) and socioeconomic sciences to agroforestry. Although the major focus of the book is on the tropics, where the practice and potential of agroforestry are particularly promising, the developments in temperate zone agroforestry are also discussed. This text is recommended for students, teachers, and researchers in agroforestry, farming systems, and tropical land use.