Olaniyan, G.O, V.M. Manyong and B. Oyewole
An opinion survey of the village extension agents in about 1300 cells of the Nigerian middle belt indicated that yam was the first crop of the cropping system in terms of area cultivated in more than 50% of cells. It was one of the five main crops (yam, sorghum, cassava, rice, and maize) in 100% of survey cells. Cassava was ranked as a first crop in less than 10% of cells. While the expansion of yam was recorded in only about 12% of cells cassava cultivation was found to be expanding in about 43% of cells. The observed changes in crop enterprises are an indicator of both diversification and intensification in agricultural practices. Criteria on the diversification and intensification of agriculture were then used to make a typology of cells and to select sites for detailed studies. The challenge in the middle belt is to sustain yam production in an intensified land use while capitalizing on the dynamics of cassava.