Adoption and Income Effects of Biofortified Cassava Varieties in Southwestern Nigeria

Abstract Biofortified cassava offers potential nutritional and livelihood benefits to smallholder farmers; however, evidence on the factors influencing its adoption, intensity of use, and associated income outcomes remains limited. This study examined the determinants of adoption and adoption intensity of biofortified cassava varieties and assessed their relationship with farmers’ income in Oyo and Ogun States, Southwestern Nigeria. A multistage sampling procedure was used to collect cross-sectional data from 648 cassava-farming households. Descriptive statistics, gross-margin analysis, a Double-Hurdle model, and an instrumental-variable approach were employed. Within the study sample, 42.75% of households adopted biofortified cassava varieties. The adoption decision was positively influenced by education, farm size, extension contact, yield attributes, dry-matter content, market demand, and product price, although effects varied across locations. Adoption intensity was particularly associated with household resource endowments, extension contact, pest resistance, market demand, and product price. Gross-margin analysis showed that adopters earned ₦319,850/ha compared with ₦263,450/ha among non-adopters, representing an observed difference of approximately ₦56,400/ha. After accounting for the potential endogeneity of adoption using an instrumental-variable specification, the findings indicate that adoption of biofortified cassava was positively associated with higher annual cassava farm income and improved profitability among sampled households. The findings highlight the importance of extension services, access to planting materials, farmer-preferred agronomic traits, and remunerative markets in promoting adoption. Policies strengthening technology dissemination and output-market development could enhance the livelihood benefits associated with biofortified cassava cultivation. This study contributes directly to several Sustainable Development Goals (SDGs), particularly SDG 1 (No Poverty), SDG 2 (Zero Hunger).