Socioeconomic Determinants of Crop Diversification Among Smallholder Farmers in Adamawa State

Crop diversification is widely documented as a risk management strategy and a pathway to dietary improvement and income stability for smallholder farm households. In Adamawa State, in Nigeria's North East geopolitical zone, where both climatic stress and market access constraints are pronounced, understanding what drives crop diversification decisions has important implications for rural development programming. This study analyses the socioeconomic determinants of crop diversification among smallholder farmers in Adamawa State. Cross-sectional data were collected from 240 farming households across four local government areas using a structured questionnaire. A diversification index combining the Herfindahl-Hirschman Index and the crop portfolio breadth measure was constructed. Tobit regression was applied given the bounded nature of the diversification index. Control variables included household demographics, asset endowments, market access variables, and institutional factors. Results indicate that farm size, access to extension services, and proximity to markets are the strongest positive determinants of diversification. Conversely, households with dominant participation in contract farming arrangements that mandate specific crops showed lower diversification scores. Female-headed households diversified more extensively, particularly into high-value vegetables and legumes, which the study attributes to lower risk tolerance and higher nutritional prioritisation. Land insecurity was negatively associated with diversification among tenant farmers. The study recommends design of market linkage programmes that permit rather than restrict crop portfolio flexibility and targeted diversification support for tenant farming households in Adamawa State. Keywords: crop diversification, Herfindahl-Hirschman Index, smallholder, Adamawa State, risk management