@INBOOK {KEATINGE:2001, title = {Sustaining soil fertility in West Africa in the face of rapidly increasing pressure for agricultural intensification}, author = {Keatinge, J. and Breman, H. and Manyong, V. and Vanlauwe, B. and Wendt, J. }, year = {2001}, type = {Sustaining soil fertility in West Africa Vol 58}, pages = {1--22}, publisher = {Madison, WI USA: Soil Science of America (SSA); American Society of Agronomy}, }