Livelihood impact of alternative crop adoption under climate stress: a meta-analysis

Climate change is depressing yields of major staple crops, heightening pressure on farming systems and accelerating crop transitions in marginal environments. In response, farmers are increasingly adopting stress-tolerant alternative crops as an adaptation strategy. However, evidence on the livelihood associations of such adoption remains fragmented. To address this gap, this meta-analysis quantifies the associations between stress-tolerant alternative crop adoption and livelihood outcomes (income, food security, resilience and adaptive capacity). Meta-regression is used to assess spatiotemporal heterogeneity and examine whether estimated associations vary across key explanatory factors, crop types and regional contexts. Based on 56 empirical studies published between 2000 and 2025, 247 percentage-change effect-size estimates were extracted across the broader evidence base. Results suggest that drought-tolerant crops are positively associated with food security-related outcomes (β = 0.175; p < 0.05), heat-tolerant crops with resilience-related outcomes (β = 0.549; p < 0.01), and salt-tolerant crops with positive associations across income (β = 0.195; p < 0.10), food security (β = 0.225; p < 0.10), resilience (β = 0.395; p < 0.01) and adaptive capacity (β = 0.683; p < 0.01). Adoption-related associations are consistently linked to institutional support, credit access and market linkages, although the relative importance of these factors varies by climate stressor. Overall, the findings suggest that stress-tolerant alternative crop adoption is more consistently associated with food security and resilience than with short-term income-related outcomes, and that policy design may benefit from greater attention to stressor-specific adoption conditions.