Agricultural Knowledge Systems and Behavioural Determinants of Smallholder Farmers’ Adoption of Underutilised Crops in South Africa

Underutilised indigenous crops (UICs) are increasingly recognised for their potential to contribute to climate-resilient agriculture, dietary diversification, and household food security among smallholder farmers in South Africa. However, evidence regarding farmers’ knowledge, attitudes, and practices (KAP) toward these crops remains limited. This study examined the KAP of smallholder farmers toward UICs and assessed factors associated with their adoption in selected municipalities of South Africa. A quantitative cross-sectional survey was conducted among 205 smallholder farming households using a structured questionnaire. Respondents were selected through a multi-stage sampling procedure involving purposive, snowball, and stratified sampling. Data were analysed using descriptive statistics, Ordinary Least Squares (OLS) regression, binary logistic regression, and bootstrap mediation analysis. Results showed that smallholder farmers generally possessed positive knowledge and attitudes toward UICs, particularly regarding their nutritional value, adaptability to local climatic conditions, and contribution to household food security. However, utilisation practices remained uneven across households. Age, farming experience, water availability, extension support, and market access were significantly associated with adoption. Formal bootstrap mediation analysis (1000 simulations) did not support attitudinal mediation of the knowledge-adoption relationship (ACME = −0.007, 95% CI: −0.079 to 0.059, p = 0.802), suggesting that knowledge operates through mechanisms other than attitudinal change. The study concludes that UICs possess significant potential to contribute to food security and climate adaptation in the study areas, but stronger institutional support, extension services, and market development are required for wider adoption.