Unlocking the potential role of neglected and underutilised crops in enhancing food security and building a climate-resilient food system for rural households in KwaZulu-Natal, South Africa.

Abstract

Climate change and food system homogenisation threaten agricultural biodiversity and nutritional security, with smallholder farmers in developing regions facing heightened vulnerability. This study contributes new empirical evidence on the status, determinants, and impacts of cultivating neglected and underutilised crops (NUCs) among smallholder farmers in KwaZulu-Natal, South Africa, where declining agrobiodiversity undermines dietary resilience and climate adaptation. Using data from 319 smallholder farmers across uMkhanyakude and King Cetshwayo District Municipalities, and employing Tobit regression, investment appraisal, and an Ordered Probit Endogenous Switching Regression model, the study reveals a moderate adoption rate (40%). Adopters are predominantly older, female, married farmers with stronger traditional knowledge and notably less engagement with formal agricultural institutions, a counter-intuitive finding that challenges conventional extension assumptions. Adopters achieved significantly higher net profits (ZAR 8,500/ha) and superior investment returns (IRR 38.2%), with strong resilience to market and yield shocks. The OP-ESR model confirms causal welfare impacts: adoption increased dietary diversity and alleviated food insecurity, with counterfactual analysis revealing larger potential gains for non-adopters. The study makes three explicit contributions to knowledge. First, it provides empirical evidence in the South African smallholder context that formal institutional factors, such as education, access to extension services, and agricultural training, negatively correlate with NUC adoption, whereas indigenous knowledge and cultural affiliation are the primary drivers. Second, using counterfactual analysis, it demonstrates that non-adopters stand to benefit more from adoption than current adopters, with direct implications for intervention targeting. Third, it uniquely shows that incorporating NUCs (pumpkin leaves, beans, cream-fleshed sweet potato) into culturally central staple foods improves protein quality, fibre, mineral content, and amino acid profiles without compromising consumer acceptability, thereby bridging agrobiodiversity conservation with tangible nutritional outcomes. The study concludes that NUCs offer a viable pathway for enhancing economic resilience, food security, and dietary quality. Scaling their impact requires policies that formally recognise indigenous knowledge, reorient extension services, and implement gender-sensitive interventions targeting female custodians of these crops.