Factors influencing farming households’ climate change adaptation strategies in Central Vietnam

PLOS One | https://doi.org/10.1371/journal.pone.0328058 July 10, 2025 16 / 22 The role of education as both an enabler and a filter for adaptation strategy selection is also noteworthy. While higher levels of education were associated with a reduced likelihood of engaging in labor-intensive agricultural adaptations such as shrimp or salt-tolerant rice cultivation, they were positively linked with more knowledge-intensive approaches like the lotus-fish model. This finding resonates with the work of Batunga-wayo et al (2023) and Cammarano et al (2020) who posited that education increases farmers’ capacity to process information, evaluate risk, and innovate [14,61]. However, it may also suggest a movement among better-educated individuals away from traditional agriculture toward non-farm income activities, reflecting structural shifts in rural labor markets. Age and farming experience exhibited a dual role in shaping adaptation behaviors. Older farmers were more inclined to maintain traditional practices, such as rice farming using salt-tolerant varieties, possibly due to risk aversion and accumu- lated knowledge. In contrast, younger or more experienced farmers appeared more open to adopting complex systems like lotus-fish farming or diversifying into aquaculture. These results parallel observations by Akum et al (2022) and Der Tambile et al (2024), suggesting that age is not only a proxy for experience but also for behavioral rigidity, whereas experi- ence enhances capacity for strategic adaptation depending on perceived risk and opportunity [1,10].

The significance of household income in determining adaptation choices cannot be overstated. Households with higher income levels were more capable of investing in capital-intensive adaptation methods such as shrimp farming and aqua- culture systems. Conversely, households with limited income were more likely to rely on traditional or subsistence strat- egies, and less likely to engage in innovation. The negative association between income and vegetable production may reflect both its low economic return and high labor input, discouraging wealthier households from pursuing it. This aligns with findings from Li et al (2023) and Datta et al (2024), who highlighted the pivotal role of economic resources in enabling or constraining adaptive choices, particularly in resource-scarce settings [6,20]. From an environmental perspective, both the extent of salinized land and the spatial position of agricultural plots emerged as significant determinants of strategy selection. Households experiencing severe salinity on their plots favored the adoption of more resilient rice varieties, whereas those in moderately affected areas diversified toward aquaculture or integrated farming. These patterns reflect an adaptive logic based on land suitability and are consistent with studies by Ayal and Leal (2017) and Ayal et al. (2021), who emphasized that agro-ecological conditions critically shape both the feasibility and profitability of adaptation strategies. The salinity threshold, beyond which certain crops or models become

unviable, presents a strong environmental constraint that must be incorporated into local planning and land use zoning [38,63]. Institutional factors—notably access to information, credit, training, and civic networks—were also found to play a vital role in facilitating adaptation. Access to climate-related information from public authorities significantly increased the likelihood of adopting salt-tolerant rice and shrimp farming. This finding aligns with Getahun et al. (2021), who argued that timely and reliable information is essential for informed decision-making [39]. Membership in civic organizations such as the Women’s Union also increased the probability of adopting all four strategies, underscoring the role of collective action and social capital in building adaptive capacity. Particularly in Vietnam, where the Women’s Union has been instrumental in disseminating information, facilitating microcredit access, and organizing training sessions, these organizations serve as critical intermediaries between state-led adaptation policies and community-level action. Interestingly, while access to public credit had a modest influence—only significantly affecting shrimp and lotus-fish adoption—it reveals deeper structural limitations in the rural credit market. Many households remain excluded from formal financial services, limiting their ability to make upfront investments in adaptive infrastructure or technologies. This finding echoes the conclusions of Saguye (2016) and Belay et al. (2017), who noted that credit constraints remain one of the

most significant barriers to smallholder adaptation across developing countries [41,55]. Participation in training programs had a robust and positive effect on the adoption of nearly all adaptation strategies, with the exception of vegetable production. This supports the view that climate adaptation, particularly in contexts involv- ing technical innovations or ecological complexity (e.g., saline-affected land), requires continuous learning and institutional