Adaptation to flood and salinity environments in the Vietnamese Mekong Delta: Empirical analysis of farmer-led innovations

Extremes of wet and dry weather experienced in the UK in recent years have raised many questions and issues about traditional water management and farming practices. Farm infrastructure and traditional machinery have been found to be limited when addressing these issues, which include increases in flooding, diffuse pollution and the inability to access land to carry out basic farming operations. This paper reviews reactions to these issues from those tasked with addressing them in the short and long term. Drawing on theories of learning systems, it considers the nature of some of the learning that has taken place and what kinds of social infrastructure can support such learning. Implications for future learning system design are discussed. Key examples are drawn from two research contexts, one concerned with a new generation of agricultural machines and the other with water management, governance and climate adaptation.

The water budget in the Vietnamese Mekong Delta (VMD) depends heavily on rainfall which play crucial roles in supporting agriculture, aquaculture, and local livelihoods. This study evaluated rainfall trends across the VMD from 1978 to 2022, revealing significant spatial and seasonal variations. While a few inland stations showed marginal increases in dry season rainfall, our findings indicate an overall decline in both wet and dry season rainfall across the region. This trend is particularly concerning for coastal areas, such as Ca Mau Province, which rely predominantly on rainfall due to limited upstream inflows; these areas recorded substantial declines in annual and wet season rainfall, with Sen’s slope values of –7.582 mm/year and –6.335 mm/year, respectively. Although the VMD is situated within the Asian monsoon region, geographical factors, including coastal and inland locations, exert a strong influence on rainfall variability patterns across the delta. The observed rainfall decline has critical implications for water resource management in the VMD, where climate variability is projected to increase. Although other factors, such as evapotranspiration and land use changes, also impact water availability, our study focuses on rainfall’s direct role. These findings highlight the necessity for adaptive water management strategies that account for declining rainfall, particularly in vulnerable coastal areas. This study provides a critical analysis of rainfall trends in the VMD to inform adaptive water resource strategies under climate variability, answering how these long-term trends affect the region’s water availability and resilience, and contributes to the broader understanding of climate change impacts, informing both regional adaptation strategies and global climate policy formulation.

The Vietnamese Mekong Delta is the most important agricultural production area in Vietnam. Most of this deltaic plain has an extremely low mean elevation of about 0.8 m above sea level and dissected by an inter-linked system of natural rivers and man-made canals connected to the sea. It is recognized as one of the areas worldwide most vulnerable to the impacts of climate change. In recent years, saline intrusion into the Vietnamese Mekong Delta has become increasingly serious due to a combination of factors, including the low topography, a dense system of rivers and canals connected to the sea, drought, low flow rates in the Mekong River during the dry season, growing competition for rapidly depleting water resources, sea level rise, and land subsidence. In 2020 saltwater intruded further inland than ever before and affected 10 out of 13 provinces of the Vietnamese Mekong Delta, causing severe damage to millions of hectares of farming land and the livelihoods of thousands of households. Solutions and adaptation strategies include storage of fresh water in ponds, shifting to farming systems and varieties that are more resilient to high salinity, changing cropping schedules, and building sluices to regulate saltwater intrusion. This paper discusses the main causes of salt intrusion, its effects on people’s life and production, and adaptation strategies to mitigate its impacts.

The Vietnamese Mekong Delta faces severe flooding challenges due to variations in Mekong River flows combined with extreme weather conditions. Despite these adversities, agricultural sectors in VMD have demonstrated remarkable development and resilience in flood circumstances over time. This study examines the participatory efforts of farmers and governments of the social hierarchy in Cho Moi district, An Giang province, to improve flood resilience for agricultural development. The investigation draws on information collected through a focus group discussion, a semi-structured survey of 10 government officials, a structured survey of 127 farmers, and secondary documents. The analysis reviews that the full implementation of the South Vam Nao scheme, led by the government following the success of the earlier North Vam Nao project, has encouraged farmers to innovate their farming practices. The study also underscores the crucial role of innovative strategies and policies in directing farming practices; for instance, introducing flood-tolerant rice varieties, implementing seasonal planting calendars, and organizing formal group discussions and training sessions. Such initiatives have motivated farmers to take advantage of the flood-control infrastructure established under the scheme to enhance their agricultural productivity. Notable models include growing durian on raised beds, converting rice fields to fruit tree cultivation, adopting the 3B model (Cow - Corn - Biogas), and using crop rotation systems such as the “2-year-5-crop” and “3-year-8-crop” models. The experience learned in the Cho Moi case indicates the value of coordinated flood resilience measures and is referable for other areas in the VMD and beyond.

Sustainability of rice-based livelihoods in the upper floodplains of Vietnamese Mekong Delta: Prospects and challenges

Resilience of various innovative water management practices: The case of rice production in the Vietnamese Mekong Delta floodplains

In response to the increasing impacts of climatic stressors on human populations, climatic scholars have emphasized the need for alternative approaches to adapt food crop production to climate change and sustain the livelihoods of smallholder farmers. Inspired by agro-ecological intensification (AEI) practices of smallholder farmers, this study contributes to climate change adaptation debates in Sub-Saharan Africa by providing a context-specific exploration of everyday traditional soil and water management practices employed by smallholder farmers in adapting food crop production to climate change. The study employed a qualitative research design, conducted household case studies, focus group discussions, key informant interviews, and a review of secondary data. We show that smallholder farmers employ diverse range of agronomic practices, with a particular emphasis on traditional soil and water management techniques. Such as the preparation and application of organic manure and compost, ridges formation, crop rotation, and cover cropping. These agronomic practices were complemented by the application of limited inorganic fertilizers and applied across different types of farms; compound and bush farms, valley fields, and gardens to adapt production to climate change. We argue that smallholder farmers are more inclined towards adopting AEI as a means of climate change adaptation due to their strong reliance on traditional farming methods, that draws heavily on local resources, indigenous knowledge as relatively affordable practices. Therefore, we emphasize the importance of incorporating an Endogenous Development (ED) approach in promoting AEI as part of climate change adaptation planning, particularly in rural Ghana and other Sub-Saharan African regions facing similar conditions.

Several studies found science-based knowledge has only able to reach a small fraction of their desired recipient. To compensate for the lack of formal sources, farmers often relied on informal sources of knowledge within their farming community. This study investigates the role of farmer’s social engagement in developing farming knowledge and farmer’s decision-making. A structural equation modelling was used to test the hypothesised moderating role of social engagement among farmers on the effects of service access, training, and knowledge-sharing on farming knowledge. The study used the case of rice farmers in Northern Thailand, wherein a focus group discussion and a series of survey interviews were conducted. Study results found that social interactions among farming communities significantly moderated the effects of training and knowledge-sharing. The findings support the critical role of social engagement among farmers in increasing information flow and experiential knowledge exchange in developing farming knowledge. Furthermore, social interactions promote farming innovation and management practices through advice-seeking with other farmers. Hence, in supporting farming sustainability, extension support should also focus on network building among actors within the farming community and understand how farmers exchange experiential knowledge to compensate for the lack of formal sources of knowledge.

Food production in delta areas such as the Vietnamese Mekong Delta (VMD) faces pressures from climate change effects, primarily salinity intrusion and drought. This urges a transition towards a more sustainable food system, which is better able to deal with the pressure factors. Multiple transition pathways are considered, including implementing adaptation strategies at the primary production stage. However, these changes may affect food safety. This study applied a qualitative framework to investigate changes in the occurrence of food safety hazards resulting from adopting adaptation strategies at primary production. We selected three case studies (CS) in the VMD: (1) adaptation in the usage and application of water sources for agricultural production, (2) shifting from monoculture rice, duck, and fish to an integrated crop-livestock farming, and (3) introduction of a new crop (i.e., quinoa). Potential microbiological and chemical hazards were assessed based on a literature study and expert input, and their likelihood of occurrence in each future scenario was compared to the current situation. The simplified approach was considered functional given the limited data for future scenarios. Our theoretical analysis showed that applying different types of fresh water resulted in different hazards (CS 1). Similarly, hazards in integrated farming (CS 2) would differ from those in separate farming. Quinoa production (CS 3) might result in similar or reduced hazards compared to rice. Regardless, building awareness on quinoa safety as a new commodity is crucial. The results of this analysis can inform policymakers and stakeholders to prioritize food safety hazards for mitigation and monitoring, and ultimately facilitate the joint efforts towards a “safe-by-design” food system transition. • A comprehensive evaluation of a food system transition must include food safety. • To this end, a qualitative framework was applied. • The framework was applied to three case studies in the Vietnamese Mekong Delta. • It helped to identify changes in occurrence of potential food safety hazards. • Data gaps on food safety before and after food system transitions were identified.

The Vietnamese Mekong Delta (VMD) has an important role in terms of food security and socio-economic development of the region. The VMD is a densely populated area and is a social and economic hotspot for coastal hazard risks and vulnerability. The amount of people exposed to flooding, storm surges and seasonal river floods in VMD is estimated to increase as the sea level rises, land-use changes and urbanization in flood-prone areas is growing. Therefore, it is necessary to focus on assessing and mapping flood hazard, risk and vulnerability of the Mekong delta. There are many flood hazard and risk studies carried out in the VMD, however very little is done with respect to vulnerability. The region is facing a rapid economic growth and vulnerability to floods becomes an important issue to be addressed.The study presented here focuses on mapping of the vulnerability of the VMD, based on the situation in the area and on the available data. The study evaluates the VMD districts from vulnerability point of view and presents maps, which will be helpful to the decision makers who need to take measures on how to reduce and mitigate the flood impact in the area. Collaboration between deltas' administrations, multiple stakeholders and organizations, at national and international level (delta alliances), has to be undertaken to support the most vulnerable areas and to learn from each other. Mapping vulnerability offers the opportunity to get a broad overview on affected areas and on possible adaptation options that could be applied, directing resources at more in-depth investigation of the most promising adaptation strategies. Moreover, at a later stage, it can also serve to evaluate the effectiveness of the adaptation measures.The present study presents a map of flood vulnerability for the VMD for the years 2000 and 2050 (see Main Map). The map is created by applying Coastal Cities Flood Vulnerability Index (CCFVI) methodology; the flood map will overlay flood hazard in order to create flood risk maps using tools such as ArcGIS.

Biochar application is considered a potential approach to mitigating greenhouse gas emissions (GHGs) from the agricultural sector and improving soil physicochemical properties. Thus, we conducted a field experiment to examine the efficacy of biochar application rates in combination with water management practices on soil methane (CH4) and nitrous oxide (N2O) emissions and carbon increment in the Vietnamese Mekong Delta (VMD). Rice husk biochar (RB) and Melaleuca biochar (MB) were incorporated in the topsoil (0–20 cm) at 5 and 10 Mg ha−1, followed by the water management regimes of continuous flooding (CF) and an alternative wetting and drying (AWD). The results identified that biochar application rates and water management measures were major factors in decreasing CH4 and N2O emissions. Compared with the conventional practice, the RB and MB amendment in the rice fields under CF practices reduced 12.9–21.3% of total GHGs (tGHGs), while biochar incorporation under the AWD management practice reduced from 22.3% to 30.5% tGHGs. Compared to CF treatments, biochar amendment concerning the AWD regime lowered from 25.4% to 31.6% tGHGs. Increasing biochar from 5 to 10 Mg ha−1 did not reduce tGHGs considerably. We identified that biochar application significantly increased grain yields from 12.8% to 20.6% under the CF management practice, while the percentage varied from 2.5% to 3.8% for the AWD practice. Similarly, higher grain yields were achieved from 4.9% to 13.7% by applying AWD compared to the CF treatments. Our findings showed that although higher biochar application rates could reduce the tGHGs, the difference in biochar types and water management applications in connection with the tGHGs was neglectable. Incorporating biochar enhanced soil bulk density and porosity under AWD and CF practices. Going forward in further studies, we recommend a long-term biochar application in the VMD’s low-lying paddy fields with a broader range of biochar rates under different soil types.

Chapter 16 - Farmers’ livelihoods and adaptation in the Vietnamese Mekong Delta: Current practices and policy implications

Vulnerability and ecosystem-based adaptation in the farming communities of droughtprone Northwest Bangladesh

Farming communities in the Vietnamese Mekong Delta (VMD) face a range of socio-economic and environmental pressures. With out-migration and changing career opportunities, many young people are unwilling to remain in agriculture and prefer careers elsewhere due to poor perceptions of farming as a career. To better understand the educational choices and career aspirations of rural youth in the VMD and the contextual factors affecting these choices, we used an online survey and several focus group discussions to consult university students about their selection of university major, their career aspirations, the role of climate change and other pressures, and opportunities available to alleviate these pressures. Farming itself was an unattractive career pathway, though agricultural services, research and extension were relatively popular. Climate change may reduce agricultural employment prospects, requiring some respondents to pursue other, less impacted careers. Other pressures reported included a lack of certain workplace skills; gendered differences in career prospects and sectors; inadequate personal networks; and COVID-19 economic impacts. Government and private sector initiatives may help alleviate these pressures via educational, financial and entrepreneurial support, valourising diverse career pathways, and ensuring improved inclusivity for youth in rural communities.

Development strategies increasingly emphasize agricultural development, employment, and equity; it is therefore important to examine the role of education in light of these new emphases. The purpose of this paper is to synthesize the conclusions of a number of studies of the effect of a farmer's educational level and exposure to extension services on his productivity. Eighteen studies conducted in low-income countries provided 37 sets of farm data that allow a statistical estimation of the effect of education. The overall conclusion of this paper is that farm productivity increases as a result of a farmer's completing at least 4 additional years of elementary education rather than none. Also, the effects of education were much more likely to be positive in modernizing agricultural environments than in traditional ones.