@ARTICLE {SANGINGA:1997, title = {Nitrogen fixation and N contribution by promiscuous nodulating soybeans in the southern Guinea savanna of Nigeria}, author = {Sanginga, N. and Dashiell, K. and Okogun, J. and Thottappilly, G. }, journal = {Plant and Soil}, year = {1997}, volume = {195}, pages = {257--266}, issn = {0032-079X}, }