Mekong Delta Research Articles

Evaluating the Performance of Alternate Wetting and Drying Irrigation Technology: An On-farm Rice Case Study in An Giang Province, the Mekong Delta of Vietnam

Alternate wetting and drying irrigation (AWD) is a promising technique that has been tried across Southeast Asia to reduce water consumption and methane emissions in irrigated rice cultivation. The study conducted in the upper Vietnamese Mekong Delta compared the effectiveness of plant growth, yield components, and yield under three different water application regimes: the treatments of community AWD (AWD_C), household individually (AWD_H), and continuous flooding (CF) with the expectation to explore the ability to use water effectively in rice cultivation. The results showed no significant difference in water use between the three treatments. However, there was a considerable difference in coefficient of variation value (CV); the CV value of the water column in the AWD_C (1.32%) was a significant difference from that of AWD_H (0.87%) and CF (0.89%). The mean chlorophyll content, the yield, and the weight of 1,000 grains of the AWD_H treatment were significantly higher than that of the other two treatments. In another aspect, the water productivity of the AWD_H treatment was the highest (0.66 kg/m3), a statistically significant difference compared to the AWD_C and CF (0.37; 0.33 kg/m3). In conclusion, the AWD_H shows efficiency in leaf chlorophyll content, 1,000-grain weight, yield, and water productivity. The AWD_C is inferior to the AWD_H due to the large variation of field elevation. It is noted that field elevation is critical to the technique’s success in being applied on a large scale.

Land Accumulation and Economic Efficiency in Extensive Black Tiger Shrimp Farming in the Vietnamese Mekong Delta

Land Accumulation and Economic Efficiency in Extensive Black Tiger Shrimp Farming in the Vietnamese Mekong Delta

Dissolved and particulate metals and metalloids in the eastern Mekong Delta, Vietnam

The article reports the concentration levels of particulate and dissolved metals and metalloids (Be, Se, Sb, Tl, V, Pb, Cd, Cu, Zn, Ni, Mo, Co, Fe As, Ag) in the eastern region of the lower Mekong Delta (Vietnam) in order to assess their possible influence on the environmental quality of river water. To measure the concentrations of trace elements, a mass spectrometric method was used. The critical particulate elements had included V, Cu, Ni, Co, Pb, Cd and potentially critical – Mo, Ag, Se, Tl. In the dissolved phase these were Cu, Zn, and Pb, Cd, Co, Ag, Se respectively. The high accumulation ability of studied elements to suspended particulate matter (102–107) suggests their important role in the distribution of elements. The water salinization boundary in the riverbeds of the delta moves upstream 30–50 km further in the dry season compared to the wet season.

Mechanized wet direct seeding for increased rice production efficiency and reduced carbon footprint

Crop establishment is one of the major rice production operations that strongly affects rice production, productivity, and environmental impacts. This research introduced a new technology and provided scientific evidence for the benefits of mechanized wet direct seeding (mDSR) of rice as compared with the other crop establishment practices commonly applied by farmers for wet direct seeded rice in Mekong River Delta in Vietnam, such as seeding in line using drum-seeder (dDSR) and broadcast seeding (bDSR). The experiment was implemented across two consecutive rice cropping seasons that are Winter-Spring season and Summer-Autumn season in 2020–2021. Treatments included (1–3) mDSR with seeding rates of 30, 50, and 70 kg ha− 1, (4) dDSR with 80 kg ha− 1 seed rate, and (5) bDSR as current farmer practice with seeding rate of 180 kg ha− 1. The fertilizer application was adjusted as per seeding rate with 80:40:30 kg ha− 1 N: P2O5: K2O with lower seed rate 30 and 50 kg ha− 1 in mDSR; 90:40:30 kg ha− 1 N: P2O5: K2O with medium seed rate of 70 to 80 kg ha− 1; and 115:55:40 kg ha− 1 N: P2O5: K2O with high seed rate of 180 kg ha− 1 in bDSR. Mechanized wet direct seeding rice with a lower seed rate of 30 to 70 kg ha− 1 and fertilizer rate by 22–30% reduced variation in seedling density by 40–80% and in yield by 0.1 to 0.3 t ha− 1 and had similar yield to bDSR. In consequence, N productivity was 27 and 32% higher in mDSR as compared to bDSR during the Winter-Spring season and Summer-Autumn seasons, respectively. The use of lower seed rate and fertilizer in mDSR also led to higher income and lower carbon footprint (GHGe per kg of paddy grains) of rice production than the currently used practices of bDSR. Net income of mDSR was comparable to that of dDSR and higher by 145–220 and 171–248 $US than that of bDSR in Winter-Spring season and Summer-Autumn, respectively. The carbon footprint of mDSR rice production compared to bDSR was lower by 22–25% and 12–20% during the Winter-Spring and Summer-Autumn seasons, respectively. Given the above benefits of farming efficiency, higher income, and low emission, mDSR would be a technology package that strongly supports sustainable rice cultivation transformation for the Mekong River Delta of Vietnam.

The Role of Compost and Biochar in Improving Saline-Affected Soil Characteristics and Total Nutrient Uptake of Rice Grains in The Mekong Delta, Vietnam

The Role of Compost and Biochar in Improving Saline-Affected Soil Characteristics and Total Nutrient Uptake of Rice Grains in The Mekong Delta, Vietnam

The Factors Influencing the Depression, Anxiety, and Stress of Grassroots Healthcare Workers in the Context of the Covid-19 Pandemic in the Vietnamese Mekong Delta: A Cross-Sectional Study in An Giang Province

Introduction: Grassroots health workers are crucial in Vietnam's healthcare system. As the frontline of healthcare, closest to the community, they are considered the backbone for disease prevention, control efforts, and initial healthcare for the population. The Ministry of Health in Vietnam has endeavored to improve infrastructure, equipment, and workforce quality, along with providing mental health care for grassroots healthcare workers to effectively carry out health education, disease prevention, and well-organized healthcare services. This paper aims to investigate factors affecting depression, anxiety, and stress among grassroots health workers in An Giang Province located in the Vietnamese Mekong Delta region. Methods: A population-based cross-sectional study was conducted using data from the 2023 Grassroots health workers in An Giang Province. A total of 466 grassroots health workers were selected. The Research method to collect quantitative data from the questionnaire tools was applied and data analysis was conducted using the SPSS 22.0. Results: The research findings showed that 18.3%, 28.8%, and 16.8% of participants exhibited symptoms of depression, anxiety, and stress, respectively, predominantly at mild, moderate, severe, and extremely severe levels. Risk factors impacting mental health included income and benefits, COVID-19 infection, and prolonged symptoms affecting physical health, as well as workplace infrastructure. Conclusions: Improving salary policies, physical health care, and upgrading workplace infrastructure will reduce the risk of mental health issues among grassroots health workers, both during the pandemic and in the future.

Farmers’ Perceived Impact of High-Dikes on Rice and Wild Fish Yields, Water Quality, and Use of Fertilizers in the Mekong Delta, Vietnam

Farmers’ Perceived Impact of High-Dikes on Rice and Wild Fish Yields, Water Quality, and Use of Fertilizers in the Mekong Delta, Vietnam

Integrated assessment of salinity intrusion and water scarcity in Ben Tre, Mekong Delta: implications for sustainable livelihoods and adaptive water management

Integrated assessment of salinity intrusion and water scarcity in Ben Tre, Mekong Delta: implications for sustainable livelihoods and adaptive water management

Food System Governance in the Cambodian Mekong Delta: Food Production, Food Security, Migration, and Indebtedness

Despite the government’s active promotion of rice production, a significant portion of the population still faces food insecurity. While existing literature often highlights the success of achieving rice surplus, few studies delve into the connections between rice surplus and food security, and critically analyze why food security is persistent. In addressing this issue, the study investigates the underlying causes of food insecurity amidst the government’s efforts to increase rice production. The study entails a comprehensive review of existing literature and an examination of food security in three provinces in the Cambodian Mekong Delta. It concludes that while rice intensification has led to increased rice production available for consumption, challenges persist in terms of access to and utilization of rice for food consumption. These challenges are attributed to increased production costs with minimal profit margins, indebtedness, migration, land grabs, water conflicts, and lack of institutional integration in food systems, compounded by the effects of climate change and environmental degradation. As a result, a farming household with one hectare of farmland cannot produce enough rice for food consumption. Consequently, young people opt to sell off their land to settle debts and seek employment opportunities in urban and overseas areas.

Multi-step-ahead prediction of water levels using machine learning: A comparative analysis in the Vietnamese Mekong Delta

This study evaluates the efficacy of five machine learning algorithms Support Vector Regression (SVR), Decision Tree (DT), Random Forest (RF), Light Gradient Boosting Machine Regressor (LGBM), and Linear Regression (LR) in predicting water levels in the Vietnamese Mekong Delta's tidal river system, a complex nonlinear hydrological phenomenon. Using daily maximum, minimum, and mean water level data from the Cao Lanh gauging station on the Tien River (2000-2020), models were developed to forecast water levels one, three, five, and seven days in advance. Performance was assessed using Nash-Sutcliffe Efficiency, coefficient of determination, Root Mean Square Error, and Mean Absolute Error. Results indicate that all models performed well, with SVR consistently outperforming others, followed by RF, DT, and LGBM. The study demonstrates the viability of machine learning in water level prediction using solely historical water level data, potentially enhancing flood warning systems, water resource management, and agricultural planning. These findings contribute to the growing knowledge of machine learning applications in hydrology and can inform sustainable water resource management strategies in delta regions.

Study of Fluctuation in Surface Water Quality in Can Tho Province (Mekong Delta, Vietnam)

Study of Fluctuation in Surface Water Quality in Can Tho Province (Mekong Delta, Vietnam)

Movement Games as a Means of Enhancing Physical Fitness and Vestibular Stability in 8-9-year-old Pupils in the Mekong Delta, Vietnam: A Case Study

Movement Games as a Means of Enhancing Physical Fitness and Vestibular Stability in 8-9-year-old Pupils in the Mekong Delta, Vietnam: A Case Study

Understanding Precipitation Moisture Sources and Their Dominant Factors During Droughts in the Vietnamese Mekong Delta

AbstractThe Vietnamese Mekong Delta (VMD) is the most productive region in Vietnam in terms of agriculture and aquaculture. Unsurprisingly, droughts have been a prevalent concern for stakeholders across the VMD over the past decades. However, the VMD precipitation moisture sources and their dominant factors during drought conditions were not well understood. Using the ERA5 reanalysis data as inputs, the Water Accounting Model‐2layers (WAM‐2layers), a moisture tracking tool, was applied to identify the VMD precipitation moisture sources from 1980 to 2020. The modeling simulation indicates that the moisture sources transported from the upwind regions dominate the VMD precipitation by 60.4%–93.3%, and the moisture source areas vary seasonally with different monsoon types. Results of the causal inference algorithms indicate that the humidity and wind speed in the upwind area are the dominant factors for driving moisture transport and determining the amount of VMD precipitation in dry and wet seasons, respectively. The local atmospheric conditions may also have a causal effect on moisture recycling. During the drought events in 2015–2016 and 2019–2020, the reduced moisture transport in the 2016 dry season was mainly caused by the anomalies in both humidity and wind speed, while the below average moisture sources in the 2020 dry season were dominated by humidity. In the 2019 wet season, an anomaly in wind speed led to a decrease in the tracked moisture. These findings are of great significance for understanding the moisture sources of precipitation and further improving drought prediction in the VMD.

Analyzing the Characteristics of the 1968 Spring General Offensive and Uprising in the South Central Mekong Delta, Vietnam

Analyzing the Characteristics of the 1968 Spring General Offensive and Uprising in the South Central Mekong Delta, Vietnam

Macrozoobenthos of the Mekong River Delta under Conditions of Extremely Low Water

Macrozoobenthos of the Mekong River Delta under Conditions of Extremely Low Water

Evolving pathways towards water security in the Vietnamese Mekong Delta: An adaptive management perspective.

The interplay of climate change, upstream hydropower development, and local water engineering interventions for agricultural production contributes substantially to the transformation of waterscapes and water scarcity in the Vietnamese Mekong Delta. This paper aims to examine how these dynamics are linked to the paradigm shift in water management in An Giang and Ben Tre, the two ecologically distinct provinces that face serious water scarcity in the delta. We used the adaptive management concept to examine how state-led policy directions from food security towards water security enable change in water management that gives priority to water retention. While policy learning is evident, questions remain about how this ad-hoc solution could help address the presently acute water scarcity and water security over the long term. The paper advocates achieving water security should focus not only on diplomatic interventions into upstream climate-development complexities but also local water-livelihood politics.

WHY ARE INTERNATIONAL TOURISTS SATISFIED WITH ECOTOURISM IN THE MEKONG DELTA, VIETNAM?

The satisfaction of tourists plays a crucial role in the success of a tourist destination. This study aims to demonstrate factors influencing the satisfaction of international tourists with ecotourism in the Mekong Delta, Vietnam. The study employs a convenient sampling combined with direct interviews of 256 international tourists who have experienced ecotourism services in the Mekong Delta region of Vietnam. Quantitative analysis methods used in the study include testing the reliability of the scale using Cronbach’s alpha, exploratory factor analysis (EFA), confirmatory factor analysis (CFA), and covariance-based structural equation modeling (CB-SEM). The research results have proven 06 factors influencing the satisfaction of international tourists with ecotourism in the Mekong Delta, including trust, responsiveness, assurance, empathy, tangible facilities, and local characteristics. Among these, the local characteristic factor has the most impact on the satisfaction of international tourists with ecotourism in the Mekong Delta. The research results will provide managerial implications to enhance service quality and improve the satisfaction of international tourists with ecotourism in the Mekong Delta region, Vietnam.

INTENTION TO RETURN TO NATIONAL PARK: THE ROLE OF PERCEIVED QUALITY, PERCEIVED VALUE, AND TOURIST SATISFACTION

Understanding and predicting tourists’ intention to return to a destination is a fundamental factor for the success of a tourism destination. The objective of this study is to demonstrate the influence of perceived quality, perceived value, and satisfaction on the intention to return to the national park of tourists. The research utilizes a convenient sampling method with direct interview techniques to collect research data. The achieved sample size is 308 tourists who have visited and experienced tourism services at national parks in the Mekong Delta region, Vietnam. Applying a combination of qualitative and quantitative research methods, the study has proven that perceived quality positively influences satisfaction, enhancing the intention to return to national parks of tourists. Additionally, perceived value also has a positive impact on satisfaction, contributing to promoting the intention to return to national parks. Finally, the research has revealed a positive correlatio n between satisfaction and the intention to return to national parks of tourists.

Characterization of endophytic bacteria isolated from wild rice plants in the Mekong Delta, Vietnam

Abstract. Thi QVC, Minh NLK, Thuy NP, Tat TQ, Tran T. 2024. Characterization of endophytic bacteria isolated from wild rice plants in the Mekong Delta, Vietnam. Biodiversitas 25: 2576-2585. Endophytic bacteria bring many benefits to plants, such as stimulating plant growth and inhibiting many microbial pathogens that cause plant diseases. Hence, this investigation aimed to evaluate the association of endophytic bacteria with wild rice (Oryza rufipogon) that can fix nitrogen, solubilize phosphorus and produce indole-3-acetic acid (IAA). Twelve-five bacterial strains were recovered from wild rice stems and roots collected from Vinh Long and Tien Giang provinces of the Mekong Delta. Among these strains, six had phosphorus solubilizing and seven had nitrogen-fixing activity. Strain BR3.5 fixed the highest nitrogen, i.e. ammonia (NH4+) content of 0.109 ± 0.002 mg/L after eight-day incubation. However, the highest phosphorus solubilization was recorded in two isolates, RR3.7 and RR1.1, with clear zone diameters of 0.800 ± 0.020 mm and 0.800 ± 0.030 mm, respectively. In addition, bacterial strains could synthesize IAA, and BR2.5 produced the highest, i.e., 0.067 ± 0.002 ?g/mL, IAA after eight-day incubation. Notably, strain BR3.5 exhibited multiple activities like nitrogen fixation (0.109 ± 0.002 mg/L), phosphorus solubilization (1.02 ± 0.002 mm), and IAA synthesis (0.056 ± 0.00 ?g/mL). Strain BR3.5 was identified as Pantoea sp. based on 16S rRNA gene sequencing (92.69% similarity) together with morpho-physiological and biochemical characteristics. The findings indicate that strain BR3.5 may be used for the production of biofertilizers for rice farming.

Pathogenic and Antibiotic-Resistance Genes of Pasteurella multocida Isolated from Goats in the Mekong Delta, Vietnam

Pasteurella multocida (P. multocida) is one of the predominant pathogens that mostly cause respiratory diseases in domestic animals, such as goats. To determine P. multocida serotypes and the prevalence of pathogenic and antibiotic-resistance genes the PCR method was used. A total of 143 isolated P. multocida strains were collected from 289 healthy hybrid Boer-Saanen goats’ nasal samples in the Mekong Delta, Vietnam, from March to June 2023. A total of 143 P. multocida strains, serotype B accounted for the highest proportion (51.05%), followed by serotype A (14.69%), and the lowest was serotype E (0.70%) while (39.86%) of strains could not be determined serotypes. Among the six virulence genes surveyed, the sodA gene (56.64%) had the highest presence, while the ompH gene (4.20%) had the lowest presence. Pathogenic genes were present mainly in serotypes A and B; tbpA was frequently detected in serotype A (66.67%), and sodA was commonly detected in serotype B (56.16%). There were 14 virulence gene combinations in 59/109 (54.13%) serotyped P. multocida strains, and the pattern of sodA + toxA + tbpA was prevalent at the highest rate (12.84%). Moreover, among the eight investigated antibiotic resistance genes, the sulII gene had the highest presence rate (74.13%), compared to the tetA gene with the lowest presence rate (13.29%). Gene sulII was mainly detected on strains belonging to serotypes A (80.95%), B (83.56%), and F (77.78%). A total of (77.98%) of serotyped P. multocida strains indicated multi-harbor from two to six antibiotic-resistance genes, and the most common pattern was aadB + sulII (10.09%). The prevalence of five pathogenic P. multocida serotypes harboring diverse antibiotic-resistance genes isolated from nasal samples could be a critical issue in treating and preventing the respiratory diseases caused by P. multocida in goats in the Mekong Delta.