IntroductionClimate change poses severe risks to smallholder farmers in developing regions, yet adaptation responses do not uniformly enhance resilience: some are sustainable and strengthen long-term adaptive capacity, whereas others are maladaptive and may deepen future vulnerability. Comparative evidence across regions of the Global South remains limited.MethodsFollowing PRISMA 2020 guidelines, we systematically reviewed 58 studies from 15 countries in the Southern African Development Community (SADC) and South India. We identified common crop-based adaptation strategies and classified them as sustainable or maladaptive based on their environmental, social, and economic consequences.ResultsThe most frequently reported strategies were changing planting dates, crop diversification, drought-tolerant crops, irrigation, and soil conservation. Approximately 80% of recorded strategies were sustainable, including pit planting, agroforestry, and cover cropping. However, we also identified maladaptive responses, including excessive use of chemical fertilisers, riverbank gold mining, and the sale of productive assets. The most persistent barriers to sustainable adaptation were limited financial support, poor access to climate information, and unreliable weather updates.DiscussionThese findings reveal that maladaptive responses persist where farmers face severe financial, informational, and institutional constraints. Sustainable strategies generated co-benefits aligned with SDGs 1, 2, 3, 13, and 15. Strengthening climate-resilient adaptation requires targeted support expanding access to affordable finance, bundled insurance, reliable climate services, and farmer training in sustainable practices, while discouraging environmentally damaging coping responses.