Achieving impacts at scale with integrated soil fertility management innovations in Sub-Saharan Africa: successes, lessons and prospects - Sanginga, Pascal C.; Chianu, Jonas N.; Vanlauwe, Bernard; Bationo, B. André; Smaling, E.M.A.; Woomer, P.L.; Mukunye, U; Sanginga, Nteranya (International Center for Tropical Agriculture, 2007)