Farming system is an agricultural practice involving combinations of various farming enterprises which include, but is not limited to cropping and livestock husbandry, to which resources are allocated in a view to maximizing resource use efficiency and optimizing profitability. Various farming activities in which crops and farm byproducts of livestock origin integrated into the cropping system have been undertaken by many small holder farmers. Farmers in Nigeria are not used to monocropping system which is a common practice in many developed countries of the world. They practice mixed cropping/farming system. However, farmers plant the crops haphazardly without following definite sequence and pattern. This has led to the evolvement of Farming System Research which is a scientific approach to mixed cropping/mixed farming involving CRIN mandate crops in an appropriate sequence, arrangement and geometry leading to proper intercropping that can afford optimum yield without adverse effects on the land and the environment. Research activities in the Farming System Research Programme have been geared towards intercropping CRIN mandate crops – cacao, kola, coffee, cashew and tea with other tree crops and some arable crops. This has resulted in many perfected technologies of intercropping cacao with oil palm, kola, rice, plantain, yam, maize, cassava, melon, cocoyam, cowpea, pepper and okro; kola with cocoa, cassava, maize and yam; coffee with yam, maize, cowpea and rice; cashew with cassava, maize, plantain, cowpea, rice, melon and bambara nut; tea with plantain, banana and eucalyptus. Research in farming system has also led to the development of some end-use products like CRIN black soap and organic fertilizer using cocoa pod husk. The itemized activities of Farming system research are inexhaustible as research is still in progress on integrating other farming enterprises with the CRIN mandate crops.