Dynamics of yam-based cropping systems in the Guineo-Sudanian savannahs in Benin

Dynamics of yam-based cropping systems in the Guineo-Sudanian savannahs in Benin Most yams are being cultivated after slash and burn of woody savannahs. As these zones are being turned into cultivated areas, the future of the yam is questioned. For the last 20 years, agronomists have been developing alternatives to long-term natural fallows but their adoption is still low. At the same time, areas cultivated in yam have been increasing. In order to understand actual dynamics in yam-based production systems, an exploratory study has been conducted in 10 villages of the central part of Benin, representing three levels of forest availability. Yam makes a high contribution to income in areas with high forest availability: new fields are opened by autochthonous producers as well as by new settlers. In areas with low or no forest availability, yam production has decreased but still exists, part of the fields being cultivated in a crop rotation or after livestock penning. In intermediate areas where yam was a major crop two or three decades ago, farmers cope with now low forest availability by bringing lowlands into use. These adjustments make it possible for producers to keep track of early varieties for yam fufu in spite of their high soil fertility requirements. Lowland cultivation and crop-livestock integration constitute alternative forms of intensification for producers. A sedentary system based on cover crops and agroforestry developed by researchers are not yet widely adopted. The focus of further research may have to be shifted to take farmers' adjustments into account.