Decision support tools for smallholder agriculture in Sub-Saharan Af rica : a practical guide / T.E. Struif Bontkes and M.C.S. Woperei s, (editors). - Wageningen, Netherlands : CTA, 2003 - ix, 194 p. : ill. (some col.) ; 22 cm. Includes bibliographical references. ISBN: 088090142X Subjects--Topical Terms: Soil fertilityFertilizers-- Africa, Sub-Saharan.Soil management Dewey Class. No.: 631.4