Do rice varieties matter? Climate change adaptation and livelihood diversification among rural smallholder households in the Mekong Delta region of Vietnam

While it is known that the threat of climatic stresses induces rural smallholders to diversify their livelihood strategies, a consensus has not been reached as to what type of stress induces which strategy, especially in the Mekong Delta Region (MDR) of Vietnam. Primary data were obtained from randomly selected 405 households producing rice (Oryza sativa L.) in three provinces in the MDR. Simpson's diversity index was used to assess the level of diversification, multivariate probit regression was utilized to examine the factors affecting farmers' adoption of livelihood strategies, and tobit regression was employed to examine the factors influencing the extent of farmers' diversification. The index showed relatively low levels of livelihood diversification in the study area. The results of the multivariate probit regression analysis of four livelihood strategies indicated that farmers who were exposed to drought or flood were more likely to cultivate conventional rice varieties than newer cultivars, likely because the newer varieties accessible in the study areas were of the resource-using type that were high-yielding under favorable conditions but susceptible to environmental stresses. Furthermore, those prone to salinity intrusion tended to engage in off-farm income opportunities. In addition, the results of the tobit regression analysis exhibited significant effects of asset endowment, extension services, public transport availability, agricultural inputs, and cooperative membership on the extent of livelihood diversification. To enhance rural livelihoods in the MDR, intervention programs should ensure to provide the resource-saving type of improved varieties as well as promote off-farm employment in salt-affected areas.