Rising to the challenge of sustainable intensification of agricultural production in Africa - Farming systems design to support action research for development - Groot, Jeroen C.J.; Klapwijk, C.J.; Timler, Carl J.; Bekunda, Mateete A.; Mourik, Tom A. van; Descheemaeker, Katrien K.; Tittonell, Pablo A.; Giller, Kenneth E.; Snapp, Sieglinde S.; Vanlauwe, Bernard (Wageningen University & Research, 2013)