Farmers In Vietnam Research Articles

Small-scale anaerobic digesters in Vietnam – development and challenges

Small-scale anaerobic digesters, known as biogas plants, were applied as an optimal livestock waste treatment as well as biogas supply for cooking and lighting demand for small-scale farmers in Vietnam. Although the biogas technology was introduced for nearly 30 years, the number of the constructed biogas plants is still limited. The current development of biogas plants is far below the real demand on livestock waste treatment that has increased significantly. This paper gives a comprehensive overview on the biogas plant development in Vietnam and attempts to address the challenges and discuss appropriate solutions for the further biogas development.
 Mô hìnhlên men yếm khíquy mô nhỏ (được biếtvới tên hầm ủ khí sinh học) đã được ứng dụng hiệu quả trongxử lý chất thải chăn nuôicũng nhưcung cấpnguồn nhiên liệu phục vụ nhu cầu nấu ănvàthắp sáng cho các hộ chăn nuôi nhỏ ở Việt Nam. Mặc dù đã hiện diện gần 30 năm, nhưng số lượng hầm ủ khí sinhhọc vẫn còn hạn chế. Sự gia tăng số lượnghầm ủ khí sinh học chưa theo kịp với nhu cầu về xử lý chất thải chăn nuôi đang ngày càng gia tăng. Bài báo trình bày các chặng đường phát triển của hầm ủ khí sinh học tại Việt Nam, ghi nhận các thách thức trong việcnhân rộng hầm ủ khí sinh họctrong thực tế và thảo luận một sốgiải pháp để phát triển công nghệ khí sinh học.

Survival of faecal indicator bacteria in treated pig manure stored in clay-covered heaps in Vietnam

Small-scale pig farmers in Vietnam typically store manure in heaps covered by a layer of clay. However, the hygienic quality of manure applied to agricultural soil is uncertain as storage time is determined by the need for soil fertilizer. This study aimed to assess how the storage of pig manure added straw, lime stone or urea in heaps covered by clay affected the survival of faecal bacteria. E. coli was reduced from 4log10CFU/g to below the detection limit within 2 weeks with 2% (w/w) urea (CO(NH2)2) whereas other amendments were associated with limited E. coli reductions. Enterococcus spp. were not reduced in any heaps indicating possible re-growth and that enterococci should be used as hygiene indicators with caution. Follow-up research should document the practical conditions under which the farmer practice of storing manure with a clay cover can be utilized to obtain a bactericidal effect of ammonia and a safe product with high fertilizer value.

Tropical spiny lobster (Panulirus ornatus) farming in Vietnam - bioeconomics and perceived constraints to development

This paper presents bioeconomic data on lobster farming in Vietnam, and perceived constraints to the development of the industry. The farms were found to be profitable, with an average benefit cost ratio of 1.44 and an average net revenue of 262 million VND year (or just under US$15 000 year). Investment in the enterprise is high compared with other enterprises in the region. However, disease has the potential to devastate lobster crops and there is little information available to lobster farmers about disease prevention and management. Hence, the lobster enterprise is a high-risk high-return industry. The predominant perceived constraints to the development of lobster operations include water quality and temperature issues, insufficient access to credit, good-quality affordable feed and accurate information about technology improvements in lobster farming. It seems that improving the livelihood of lobster farmers in Vietnam is dependent on reducing their dependence on wild stocks for seed and feed, improving access to credit and improving technical and market information flows. Such improvements are likely to lead to higher profitability, given high export demand and hence sustained high prices for their lobster product. © 2010 The Authors. Aquaculture Research

Survival of Ascaris eggs and hygienic quality of human excreta in Vietnamese composting latrines

BackgroundFor centuries farmers in Vietnam have fertilized their fields with human excreta collected directly from their household latrines. Contrary to the official guideline of six-month storage, the households usually only store human excreta for three to four months before use, since this is the length of time that farmers have available to produce fertilizer between two cropping seasons. This study aimed to investigate whether hygienically safe fertilizer could be produced in the latrines within this period of time.MethodsBy inoculating eggs of the helminth parasite indicator Ascaris suum into heaps of human excreta, a die-off experiment was conducted under conditions similar to those commonly used in Vietnamese latrines. Half a ton of human excreta was divided into five heaps containing increasing concentrations of lime from 0% to 11%.ResultsRegardless of the starting pH, which varied from 9.4 to 11.6, a >99% die-off of eggs was obtained after 105 to 117 days of storage for all lime concentrations and 97% of eggs were non-viable after 88 days of storage. The most critical parameter found to determine the die-off process was the amount of ammonia (urine) in the excreta which indicates that longer storage periods are needed for parasite egg die-off if urine is separated from the excreta.ConclusionBy inactivating >99% of all A. suum eggs in human excreta during a storage period of only three months the commonly used Double Vault Composting (DVC) latrine, in which urine is not separated, could therefore potentially provide a hygienic acceptable fertilizer.

Contribution of Fish Production to Farmers’ Subjective Well‐being in Vietnam – A Logistic Model

Abstract There is a growing awareness of the importance of food fish production on human nutrition, employment, poverty, and recreation. However, the role of aquaculture in livelihoods of fish farmers has not been considered rigorously. With 120 farmers interviewed in a field survey and a cumulative logistic model, this study identifies some determinants of subjective well‐being of small‐scale fish farmers in Vietnam and examines the role of earnings from fish production in generating their happiness. The results confirm that the farmers receive satisfaction from their farm working. Subjective well‐being of the farmers increases with their job satisfaction and cash earnings from fish farming. A doubling in cash returns from fish culture relative to household income raises a farmer’s happiness probability by an estimated 10.6%. Education also affects farmers’ life satisfaction. For better educated farmers, when their satisfaction from fish culture increases by one level, happiness probability is estimated to increase by 0.23%. Wild fish plays an important role in Vietnamese farmers as a doubling in relative income from wild fish captures raises their estimated probability of happiness by 139%.

Seroprevalence of Toxoplasma gondii in Cats and Pigs from Thua Thien Hue Province in Vietnam

The traditional small scale pig farmers in Vietnam keep animals in open backyard stalls and usually keep cats to catch rats and mice. Under these conditions, controlling for the exposure of pigs to toxoplasmosis, a significant zoonoses, is difficult. The purpose of this study is to investigate the seroprevalence of Toxoplasma gondii antibodies in domestic cats and pigs in T.T. Hue Province, Vietnam with commercial latex agglutination kits (Eiken-Toxocheck). A total of 155 cat and 260 pig sera samples (110 from a slaughterhouse and 150 from 6 pig farms) were collected in 2007. Among them, 112 (72.3%) cats, 62 (41.3%) live pigs and 76 (69.1%) slaughtered pigs tested positive for T. gondii antibodies (1 : 64 cut-off). The seroprevalence increases as the pig grows ; the seroprevalence of piglets less than 15kg was 16.7% and 71.0% for those over 50kg (OR=12.26, 95%CI=3.31, 45.34). We also have collected sera from the same herds of 6 farmers 2 times with 2 month interval. Of which, the prevalence rate at the first sampling was 28.4% (88 samples) and 2 months later in the 2nd sampling it was 64.0% (50 samples) (OR=4.48, 95%CI=2.14, 9.39). The results indicate a high prevalence of T. gondii in pigs under the current farming system in T.T. Hue Province, Vietnam.

Nested and teleconnected vulnerabilities to environmental change.

The vulnerability of distant peoples and places to global change in environment and society is nested and teleconnected. Here, we argue that such vulnerabilities are linked through environmental change process feedbacks, economic market linkages, and flows of resources, people, and information. We illustrate these linkages through the examples of the global transmission of severe acute respiratory syndrome (SARS) and the interdependent vulnerabilities and adaptations of coffee farmers in Vietnam and Mexico. These cases demonstrate that the vulnerability of specific individuals and communities is not geographically bounded but, rather, is connected at different scales, so that the drivers of their exposure and sensitivity are inseparable from large‐scale processes of sociocultural change and market integration. Aggregate outcomes of government policies, trends in global commodity markets, and even decisions by individuals to improve livelihood security can have negative repercussions, not only locally, through transformations of ecological systems and social relations, but also at larger scales.

Farmers, Biodiversity and Plant Protection: Developing a Learning Environment for Sustainable Tree Cropping Systems

More diverse, perennial cropping systems often have better natural mechanisms for keeping pests at bay. But while scientists emphasise the broad benefits of conservation in terms of effective ecosystem functioning, farmers are more interested in biodiversity for the provision of food or of services such as shade or windbreaks. Because of their limited knowledge of the role of biodiversity in plant protection, farmers sometimes unconsciously disturb natural regulatory mechanisms. Some citrus farmers in Vietnam introduced sapodilla as an intercrop to diversify their source of income, and because this fruit tree requires little care. However, this apparently worthwhile attempt to combine two valuable crops has misfired. The ecological conditions that traditionally sustained natural pest control in citrus have been disturbed, thus trapping farmers in the pesticide treadmill. The weaver ant Oecophylla smaragdina stopped protecting citrus from stinkbugs and leaf-feeding caterpillars after facing competition from the black ant Dolichoderus thoracicus, which favours sapodilla trees as a nesting habitat. To avoid similar scenarios in the future, methods for linking scientific research on ecosystem functions with farmers' own knowledge, experience and priorities are presented. Examples are given of ways in which farmers in perennial cropping systems learn, and how scientists can facilitate this learning process.

An analysis of insecticide use in rice: Case studies in the Philippines and Vietnam

Abstract The majority of pesticide applications by rice farmers in the Mekong Delta, Vietnam, and Leyte, Philippines, were insecticides. Farmers in Vietnam applied more insecticides per season (∼6.1 sprays) than Filipino farmers (∼2.6 sprays). About half of the insecticide sprays were organophosphates and the main chemicals were methyl parathion, monocrotophos, and methamidophos. About 22% and 17% of the chemicals in the Philippines and Vietnam, respectively, were classified as ‘extremely hazardous’ (Category la) by the WHO. Another 17% and 20% in the Philippines and Vietnam, respectively, were classified as ‘highly hazardous’ (Category Ib). High proportions of the sprays were targeted at leaf‐feeding insects which accounted for 42% and 28% of insecticide sprays in Vietnam and Philippines, respectively. In the Philippines, sprays against rice bugs accounted for 44% while in Vietnam, those against brown planthoppers accounted for 34%. Since research has shown that leaf feeder control generally does not increase yields, a large proportion of insecticides currently used may be unnecessary.