Climate change significantly threatens agriculture and food production, particularly impacting small-scale producers in low- and middle-income countries who rely heavily on rain-fed agriculture. Extreme weather events reduce crop yields, exacerbating food insecurity and poverty. To adapt, farmers employ various strategies including adjusting planting times, irrigation, intercropping, conservation agriculture, and adopting climate-resilient crops. This scoping review investigates the factors influencing the adoption of these climate-resilient crops over the past 30 years in low- and middle-income countries, focusing on small-scale producers in climate-vulnerable regions. The adoption of climate-resilient crops is crucial for enhancing food security in these regions, given their increased tolerance to various stresses, enabling them to maintain or increase yields even under adverse conditions. However, adoption rates are highly variable, prompting this study to investigate the underlying factors.

The introduction establishes the context of climate change impacts on agriculture and food security in low and middle-income countries. It highlights the vulnerability of small-scale farmers, the need for adaptation measures including climate-resilient crops, and the inconsistent adoption rates, setting the stage for the scoping review. The study defines key terms such as small-scale food producers, climate-vulnerable countries, climate resilience, climate change adaptation, climate-resilient crops, climate-smart agriculture, conservation agriculture, adoption, and gender, providing a common framework for interpreting the reviewed literature. The literature review is implicitly woven into the introduction and results sections, synthesizing existing knowledge on the adoption of climate-resilient crops and identifying knowledge gaps.

This scoping review followed the PRISMA-P (Preferred Reporting Items for Systematic review and Meta-Analysis Protocols) guidelines. A PRISMA-P protocol was registered on June 4, 2019. The researchers conducted a double-blind title and abstract screening of 5,649 citations, resulting in 568 papers selected for full-text screening. 202 papers met the inclusion criteria for data extraction. Inclusion criteria specified studies focusing on small-scale food producers in low- and middle-income countries published after 1990, with an explicit focus on climate change resilience or adaptation, crops, varieties, seeds, and adoption factors. The data extraction template documented study type, context, and themes of interest. The extracted data were qualitatively summarized to identify determinants of adoption and dis-adoption, along with policy recommendations. 89% of the included papers were from peer-reviewed journals, with mixed methods predominantly used (87%).

The analysis of 202 studies revealed that the most important determinants of climate-resilient crop adoption were: access to and effectiveness of agricultural extension services (nearly 50% of studies), education level of household heads, access to inputs (seeds and fertilizers), and socioeconomic status. These factors were consistent across sub-Saharan Africa, South Asia, and East Asia. Cereals were the most frequently studied crops (67%), while legumes were underrepresented. Adoption was primarily driven by the need to cope with abiotic stresses, with drought tolerance being the most common trait followed by water-use efficiency. 53% of studies reported that social differences (sex, age, education) influenced adoption. Dis-adoption was discussed in 12 papers, mainly attributed to technology underperformance or government policies. Access to seed was a major constraint, with social networks and information access playing key roles in facilitating adoption. The study emphasizes context-specificity and the need for holistic, multifaceted interventions, given that farmers often adopt climate-resilient crops alongside other climate-smart strategies (67% of papers).

The findings highlight the crucial role of extension services in facilitating climate-resilient crop adoption. Effective outreach and readily accessible information are vital for successful technology transfer. Education levels positively correlate with adoption, indicating the importance of investing in farmer education and awareness programs. Access to crucial inputs, such as seeds and fertilizers, is also a key factor in adoption. The significant influence of socioeconomic status underscores the need for interventions that address poverty and inequality. The study emphasizes the importance of context-specific interventions tailored to local conditions and cropping systems. The lack of adequate representation of legumes and other crops crucial for food security and nutrition in the literature represents a major knowledge gap.

This scoping review identifies key determinants of climate-resilient crop adoption among small-scale producers. The most significant factors are access to extension services, education, input availability, and socioeconomic status. The study underscores the need for holistic, context-specific interventions, addressing not only the technical aspects but also the social and economic barriers to adoption. Further research should focus on gender dynamics, dis-adoption reasons, and understudied crops like legumes. Policy recommendations include improved extension services, access to inputs and finance, and promotion of diverse, farmer-preferred climate-resilient crop varieties.

The study's reliance on existing literature may introduce biases, given that publications might overrepresent certain regions or crops. The qualitative synthesis nature of the review limits the ability to draw definitive causal conclusions. The variation in definitions of small-scale producers, climate resilience, and adoption across studies may affect the overall synthesis. The limited number of studies on legumes and underrepresentation of women's perspectives beyond household headship are also limitations. The study acknowledges the complexity of the factors influencing adoption and the context-specific nature of interventions, urging caution against generalization.