@INBOOK {NWEKE:1988d, title = {Economics of fertilizer application by different methods in a cassava-maize intercrop system}, author = {Nweke, F. and Ezumah, H. C. and Agu, M. }, year = {1988}, type = {Cassava-based cropping systems reserach 1}, pages = {124--131}, publisher = {International Institute of Tropical Agriculture (IITA)}, address = {Ibadan, Nigeria}, note = {RTB; Root and Tuber; Cassava}, }