@ARTICLE {OKPARA:2009, title = {Effect of three-year fallow with herbaceous cover legumes on soil fertility and sweetpotato production in south-eastern Nigeria}, author = {Okpara, D. A* and Ikeorgu, J. * and Njoku, J. E. * and Tarawali, G. }, journal = {African Journal of Root and Tuber Crops}, year = {2009}, volume = {7}, number = {1}, pages = {47--54}, issn = {1118-2075}, note = {RTB; Root and Tuber; Sweetpotato}, }