African farmers pursue a wide range of crop and livestock enterprises that vary both across and within the major agro-ecological zones. Food production and food security in Africa depend on many different systems, unlike other regions of the world where the contribution to food production and food security is based on a limited number of systems. For the foreseeable future in Africa a multitude of farming systems need to become more productive and to generate the desired productivity increases outlined in chapter 2. This chapter describes and characterizes the major farming systems, analyses recent trends in productivity and identifies priority systems which offer the best prospects for measurable gains in productivity and food security.