@ARTICLE {LYASSE:2003, title = {Balanced nutrient management systems for cropping systems in the tropics: from concept to practice}, author = {Lyasse, O. and Diels, J. and Sanginga, P. and Vanlauwe, B. and Merckx, R. }, journal = {Agriculture, Ecosystems and Environment}, year = {2003}, volume = {100}, number = {2-3}, pages = {99--314}, }