Effects of cropping practices and soil properties on yam (Dioscorea spp) yields in different agro-ecosystems in Burkina Faso and Côte d’Ivoire

Abstract

Yam is a staple food for millions of people however, yam yields remain low due to its high variability.
This study aims to characterize yam cropping practices and to identify yield variability determinants at
farm level in four sites in Burkina Faso and Côte d’Ivoire. A survey was done on 130 yam farmers. Yam
germination rate, density of the plantation and yields were measured. Soil samples, taken at 0 – 30 cm,
were analyzed for soil chemical properties. Individual interviews with farmers were done on seedling s,
soil fertility management. Results showed yam cropping was characterized by the use of mineral
fertilizers (93 %) in Leo and by fallow practices (90 %) in Midebdo. In Liliyo, yam cropping is
characterized by the use of smaller seeds and higher density of plantation (187.7 ± 1.0 g, 10221.0 ± 268
plants ha^-1). Leo presented highest average yield for Dioscorea rotundata (9.0 ± 5.1 t ha^-1). Density of
plantation and pHwater significantly determined yam yield variability for D. alata while for D. rotundata,
yields were affected by total P for the four sites. These results highlight the need to better understand the
underling yam yield determinants before attempting to improve yam production in West Africa.