Rice and fish are staple foods essential for food security, supplying carbohydrates, proteins, amino acids and fatty acids vital to human nutrition. In Vietnam, they also underpin local and national economies. Rice is predominantly cultivated in irrigated systems under diverse ecological and hydrological conditions, particularly in flood-prone areas that sustain wild fish habitats, aquatic biodiversity and ecosystem productivity. This review synthesizes existing knowledge and provides a comprehensive overview of the history and status of rice-field fisheries resources in the context of agricultural development in the Mekong Delta. It synthesizes evidence on the typology, technological practices, diversity of farming models, ecological interactions, economic performance and environmental sustainability of integrated rice–fish (RF) production systems. The review further identifies key drivers, benefits, constraints, policy frameworks and development opportunities, highlighting the contribution of integrated RF and rice–aquatic systems to food security, rural livelihoods, sustainable agriculture and climate resilience in Vietnam. The findings indicate a substantial decline in wild rice-field fisheries and aquatic biodiversity, primarily due to the expansion of intensive rice monocropping and aquaculture production. In response, RF farming in the Mekong Delta has evolved into multiple forms, including wild rice-field fisheries, community-based aquaculture and concurrent and rotational RF and rice–aquatic animal systems, of which the latter two are the dominant production models. Integrated RF systems are increasingly recognized as effective nature-based solutions that enhance farm incomes, improve environmental quality, and deliver ecological and economic benefits. These systems increase rice and fish productivity, diversify household income and food sources, reduce agrochemical inputs and strengthen rural well-being. However, despite these advantages, including improved soil and water quality and reduced dependence on external inputs, integrated RF systems have not been widely adopted. Overall, this review demonstrates that agro-ecological RF and rice–aquatic farming systems offer a sustainable alternative to intensive rice monoculture.

This study investigates how fish are affected by the insecticide Padan 95SP (95% cartap hydrochloride, CH) used by rice farmers in the Mekong Delta, Vietnam. The impact on survival rate, acetylcholinesterase (AChE), total red (RBC) and white blood cells (WBC), blood glucose and lysozyme activity were measured in silver barb (Barbodes gonionotus), raised in a rice field. The field experiment included a control and two treatments, 0.7 kg (R) and 1.4 kg (2 R), of Padan 95SP/ha. Each treatment had three replicates. The water concentration of Padan 95SP decreased from 38.70 and 24.27 to 2.57 and 1.47 µg/L during the first seven days after exposure in the R and 2 R treatments respectively. Although causing only a few fish mortalities, the spraying of Padan 95SP caused significant physiological and immune responses in silver barb. The strongest AChE inhibitions of 18% and 34% were reached after one day in fish from the R and 2 R treatment respectively. The fish recovered fully after seven days. After an initial small increase during the first day, the RBCs, WBCs, and lysozyme activity decreased and were significantly lower in the treatments than in the control between day three and seven, but reached normal levels after 14 days. The glucose levels increased significantly during the first three days but decreased to the same levels as the control after seven days. Despite only few fish mortalities, the results suggests that the use of Padan 95SP has a negative effect on the long-term production of healthy fish in the Mekong Delta.

Soil degradation driven by intensive management practices has become of increasing concern for olive cultivation, as trends for desertification and loss of arable land have emerged across the Mediterranean basin. Agroecological management practices, such as mulching made from olive tree pruning remains, have shown potential for improving soil structure, nutrient retention and biodiversity. This study aimed to enhance the understanding of how soil management influences soil properties and arthropod diversity in small-scale olive orchards in a heterogeneous landscape in south-west Greece. Soil was sampled from 11 orchards managed under one of two systems: conventional (herbicide use, tillage, mowing) and agroecological (cover cropping, mulching), encompassing a diversity of management practices. Physicochemical properties were measured alongside soil arthropod abundance and diversity, allowing for comparisons at two levels: between management systems and among practices nested within each system. When compared across broader systems, the agroecological orchards, compared to conventional orchards, had greater porosity (56.38% and 48.75%), and soil organic matter (8.99% and 6.87%), though differences in soil composition likely accounted for some of the variation. Additionally, metrics for arthropod diversity were improved under agroecological management, with 21% higher Shannon diversity and 16.8% greater evenness compared to conventional management. Ordination analysis and generalized linear models further supported these findings illustrating the relationship between agroecological management, soil health and arthropod diversity. These results support a growing body of research which illustrate the potential of agroecological management in enhancing soil health and biodiversity in olive orchards and contributing to the development of more resilient agroecosystems within the Mediterranean basin.

This study assesses and identify major factors of social capital that affect the use of trade credit among shrimp farmers and how these contribute to and affect the profits of households in coastal provinces of the Mekong Delta, Vietnam. Data was collected through observations, informal discussions, and interviews with 364 shrimp farmers from the Ca Mau, Bac Lieu, Ben Tre and Tra Vinh provinces. The Probit and Tobit regression models were applied to analyze and evaluate the effect of social capital on the use of trade credit and the amount of trade credit used by farmers. The results show that many social capital factors affect the use of trade credit by shrimp farmers in the investigated areas, including in descending order of importance: profit, wholesale agents, colleague-friend-family line-neighbor, and trust. Besides the factors above, other factors such as agricultural land value, households’ income, distance, experiences in shrimp production, households’ assets, savings, profits of the previous crop, and the average household income had also an effect on trade use and amount of trade credit used by shrimp farming households. 

This study investigates factors that encourage and discourage farmers to adopt rice–fish (RF) farming in the Hau Giang province in the Mekong Delta, Vietnam. A mixed-method approach was employed to collect data, comprising focus group discussions, face-to-face interviews with rice (R) and rice–fish (RF) farmers, as well as in-depth interviews with agricultural officers and selected R and RF farmers. Economic benefits are the main motivation for adopting RF farming, but suitable agro-ecological conditions, farm size and access to social networks, technical training, and support from extension officers also positively influence the adoption of RF farming. Environmental and health factors have less impact on farmers’ choice of farming. The study also identifies several barriers to the adoption of RF farming, including spatial, operational, and market barriers. To enhance the adoption of RF farming, policymakers should prioritize promoting RF farming in areas with suitable agro-ecological conditions and implement supportive measures, particularly financial assistance and technical training. Additionally, raising farmers’ awareness of both the economic advantages and long-term ecological benefits of RF farming is essential.

This study assesses the sustainability of intensive rice monocropping (IRM) and integrated rice-fish (IRF) farming in the Vietnam Mekong Delta, through systems analysis. Stakeholder (SH) consultations and a literature review were conducted to construct a Causal Loop Diagram (CLD), visualising the connections and effects of the two farming strategies across environmental, economic and social domains. 42 SHs, including farmers and scientists, assessed the impact of IRM and IRF on 42 interlinked CLD variables using a 5-point scale (-2 to 2). The SHs' scores were used to assess the farming strategies impact on 18 ecosystem services (ES) and the fulfilment of nine sustainable development goals (SDGs). The results show that IRM would have a negative impact on 14 ES, while IRF would have a positive impact on 17 ES. IRM was perceived to primarily have positive impacts on the rice yield and flood protection through an increased use of high dikes and agrochemicals, which however also was the main causes of the negative impacts on several other ES. IRF was perceived to have a positive effect on all SDGs, while IRM would only contribute to two and move away from seven SDGs. It is concluded that IRF provide a more sustainable alternative to IRM because it strengthens physical, ecological and social connections for an enhanced use of interlinked ES. This contributes to an increased productivity, farmers profit and wellbeing. IRF was also perceived to increase farming systems resilience, which is important for adapting to ongoing climate change and upstream dams.

Cartap hydrochloride (CH) is commonly used to control insect pests in the Mekong Delta, and this study assesses the effects of CH (1%, 10%, and 20% of the median lethal concentration at 96 hr value) on brain cholinesterase activity, food intake, feed conversion rate, and growth of silver barb (Barbonymus gonionotus) under laboratory conditions. The inhibition of the acetylcholinesterase activity increased with both concentration and time, reaching its peak 9 hr after exposure. After 96 hr, the inhibition remained at 10.4% in fish exposed to the lowest concentration and at 18.2% and 19.9% in fish exposed to the two highest concentrations. After 48 hr, the fish were placed in clean water, but the inhibition levels at the two highest concentrations still remained at 20% until Day 7, and only recovered fully after 14 days. The feed intake was similar between the control and all treatments, but the fish exposed to CH had higher feed conversion ratio than the fish in the control during the first 30 days. This indicates an increased stress in the exposed fish and that more energy was used for detoxification. As a result, fish in the control had gained most in weight after 60 days, whereas fish exposed to the highest level of CH had gained the least, and there was a significant effect of CH on fish growth. It is concluded that expected water levels of CH from doses commonly sprayed on rice fields may affect the health of fish in these habitats, and the use of CH should be limited, as it may negatively affect healthy fish production in the Mekong Delta, Vietnam.

This study assessed the effects of fenobucarb (F) (1%, 10%, and 20% of the LC50-96h value) on the brain cholinesterase (AChE) activity, food intake (FI), feed conversion rate (FCR), and growth of silver barb (Barbonymus gonionotus, Bleeker, 1849). It also assessed the AChE inhibition levels that cause the abnormal swimming, behavior, and mortality of silver barb and how the feeding regime affects the recovery rate of the AChE activity. The results showed that the brain AChE inhibition increased with the F concentrations. It peaked after nine hours, at 73.6% and 79.7% for the two highest concentrations, and then the AChE activity started to recover. After 96 h, the inhibition level was still 11.8% in the fish exposed to the two lowest concentrations and 30.5% in the fish exposed to the highest concentrations. Even when placed in clean water, the inhibition level in the fish that were exposed to the highest concentrations and only fed every third day was 32% after 14 days. Although there were no differences in the feed intake at any time, the fish exposed to F had a higher FCR and a lower specific growth rate and weight compared to the control fish at the later stages of the experiment. Thus, although the use of F in rice farming in the Mekong Delta may not lead to direct fish kills, it impacts the growth and health of the fish, which could have negative implications for wild fish populations and the long-term production of healthy fish in the Mekong Delta.

This study compares the food-production efficiencies of integrated rice-fish farming and rice monoculture and evaluates how these farming systems contribute to sustainable food production in the Mekong Delta. The study explores how food-production efficiencies are influenced by the systems’ ecological connectivity by comparing more integrated systems that apply integrated rice-fish farming and integrated pest management (IPM) with less integrated systems farming only rice. Rice-fish farmers with plenty of fish had significantly higher rice yields than farmers with less or no fish, especially during the second crop when the rice was grown together with the fish. A positive correlation between the fish and rice yields, indicated synergistic effects between the fish and rice, due to strengthened ecological connectivity and trophic interactions within the rice-field ecosystem. Overall, rice-fish farmers had higher rice yields than rice farmers, despite using lower amounts of fertilizers and pesticides. They also had lower rice production costs compared to rice farmers, partly because the fish helped fertilize the rice and control rice pests. They had a significantly higher profit and benefit cost ratio than rice farmers because of lower production costs, and high rice and fish yields. The results indicate that food-production efficiencies in the Mekong Delta can be enhanced through diversification and increased ecological connectivity, leading to a more efficient use of rice field ecosystem services that support a long-term and healthy production of food.

This study assesses farmers’ perceived impact of high-dikes on rice and fish yields, use of synthetic fertilizers, water quality, fish diversity, and inflow of nutrient-rich water and sediments in the Mekong Delta. Interviews were conducted with 89 farmers from three districts in the An Giang province, of which 69-98% of the agricultural land is covered by high-dikes. Only 57% of the farmers felt that the rice yields had increased after the construction of high-dikes. 93% of respondents perceived that the inflow of nutrient-rich water and sediments had decreased, and 99% felt that the use of synthetic fertilizers had increased by 26-37% after the construction of high-dikes. 94% of all farmers felt that high-dikes had impacted on the aquatic environment and water quality, which was perceived to have decreased from good to poor quality. The wild fish yield and fish diversity were estimated to have decreased by 68-83 and 75-81%, respectively, and had decreased most in Cho Moi, followed by Phu Tan and Chau Phu districts. It is concluded that high-dikes have helped to increase rice yields in some areas, but at the expense of decreased natural fertilization, water quality, fish diversity and yields, which all impact on the farmers’ profit and well-being.