Sedentary yam-based cropping systems in West Africa: Benefits of the use of herbaceous cover-crop legumes and rotation—lessons and challenges
Résumé
New farming technologies such as improved fallow of herbaceous legumes have been developed over the last 20 years as alternatives to traditional yam cropping systems in areas where shifting cultivation is no more possible. One aim of this research was to analyze actual adoption by smallholders of such a technology and influencing factors in the Southern Guinea Savannah in Benin (West Africa). On the other hand, a second objective was to measure agronomic and economic performances of the innovative yam-based cropping systems in comparison with the usual ones under producers’ natural and socioeconomic circumstances in order to discuss the technology potential for large scale adoption. Smallholders with limited land access now develop as usual cropping systems a one-year fallow of Andropogonon gayanus–yam rotation or a maize–yam rotation. Innovative sedentary yam-based systems consist of an Aeschynomene histrix intercropped with maize–yam rotation or a Mucuna pruriens intercropped with maize–yam rotation. Factors potentially affecting adoption were included in a polynomial logit model. Agronomic and economic performances were assessed by the multiple regression and net present value of the 4-years double rotation. Ranking matrix was used to highlight constraints that may impede adoption. Benefits, lessons, and challenges are discussed in this article.
Mots clés
contingent ranking matrix
legume
maize
fallow
sustainable agriculture
crop rotation
relay cropping
logit model
dioscorea
adoption de l'innovation
légumineuse
performance économique
système de culture innovant
aeschynomene
mucuna
maïs
légumineuse herbacée
jachère
agriculture durable
évaluation agronomique
rotation culturale
culture intercalaire
modèle logit
évaluation contingente
benin
afrique de l'ouest
intensification
performance agronomique