Vol. 23 No. 4 (2025): Tạp chí Khoa học Nông nghiệp Việt Nam

The experiment was conducted to evaluate the effect of eggshell powder application rates and transparent plastic mulchingon growth and yield of MD7 groundnut variety in spring season in Phu Xuyen, Hanoi. A two factor experiment was laid out in a split-plot design with three replications. The main factor consisted of three rates of eggshell powder application (200, 300, and 400 kg/ha) and the sub-factor included plastic mulching and non-mulching. The results showed that higher values of growth and yield parameters of MD7 groundnut variety were observed under plastic mulching. Comparing among the rates of eggshell powder indicated that the highest values ​​of growth and yield parameters of MD7 groundnut variety were observed at the rate of 300 kg eggshell powder/ha, except for plant height. Briefly, the results indicated that the rate of 300kg eggshell powder/ha under plastic mulching was suitable for MD7 groundnut variety interms of growth and yield in the spring season in Phu Xuyen, Hanoi.

Creeping burhead (Echinodorus cordifolius) was grown on floating raft to treat municipal wastewater with two densities: 1 plant/raft (NT1) and 2 plants/raft (NT2), and un-planted was considered as control treatment (NT0). The experiment was arranged in a completely randomized design with four replications in net house condition. The municipal wastewater was collected in Bung Xang canal, Can Tho city. The plant height and root length increased 1.7 and 1.65; and 7.07 and 6.93 times compared to the initial plants in the treatments of NT1 and NT2. The total plant fresh and dry weight in the TN1 (319.9 g/plant and 22.8 g/plant) were higher than those in the NT2 (260.0 g/plant và 17.7 g/plant), respectively. The treatment efficiency of COD, total inorganic nitrogen (TIN), and total phosphorus (TP) were 54.2 > 49.7 > 37.3%; 88.3 > 71.8 > 60.5% and 85.3 > 79.4 > 72.7% in 2 plants/raft > 1 plant/raft > 0 plant/raft, respectively. The results showed that plant density significantly affected the plant growth and wastewater treatment efficiency of E. cordifolius, especially the density of 2 plants/raft providing a higher treatment efficiency. The study opens up new opportunities for the application of aquatic plants in wastewater treatment and urban landscape creation, contributing to solving the problem of water pollution in an environmentally friendly direction.

Probiotics are known as a promising alternative to antibiotics in improving productivity and controlling infectious diseases in livestocks. The study was conducted to isolate lactic acid bacteria (LAB) with strong antagonism against some common pathogenic bacteria in livestocks. A total of 33 LAB strains were isolated from 100 chicken intestine and pork intestine samples. Among them, 5 isolates showing strong antagonistic activity against 5 pathogenic bacteria tested (S. Typhimurium, S. Gallinarum, E. coli K88, S. aureus, and C. perfringens) were identified as Pediococcus pentosaceus, Levilactobacillus brevis, Lactiplantibacillus plantarum using MALDI TOF. The LAB isolates in this study were non-hemolytic, negative for DNase production, and highly resistant to acid and bile salt. The auto-aggregation rates of the LAB isolates were all over 40% and the rates of co-aggregation of them to the pathogens ranged from 24.39% to 45.17%. In particular, all LAB isolates were determined as multi-resistant strains, with the highest resistant rates to ampicillin, erythromycin, and tetracycline. Overall, the 5 selected LAB isolates are potential strains for the production of probiotics preventing animal diseases.

High total ammonia nitrogen (TAN) can be converted into toxic ammonia under high pH, posing a threat to aquatic animals. This study evaluated the ability of Bacillus polymyxa spores imported from India in reduction of TAN in a simulated environment. 1g dose of spores (5.3 billion CFU/g) was added to freshwater and brackish water (17ppt) with TAN concentrations of 0.5, 2.5, 5.0, 7.5, and 10 mg/l. TAN was determined using a test kit A3 (Otanics, Vietnam). After 24 hours of aeration, TAN levels decreased significantly. The maximum TAN reduction rate reached 0.16-0.18 mg/l/h at a concentration of 5 mg/l. The spores exhibited better activity in brackish water than in freshwater. Further research is needed to improve the effectiveness of B. polymyxa spores.

The study was conducted to determine the appropriate non-linear function to describe the laying rate curve of fighting chickens raised at Dabaco Chicken Breeding Company. The data collected was the laying rate of two groups including 600 Black fighting and 600 Dark Brown fighting hens from 1st to 26th laying week raised in an intensive farming system. Four mathematical models Logistic, Logistic Curvilinear, Compartmental and Modified Compartmental were used to investigate laying rate curve. The results obtained included mathematical parameters of the curve, weeks of age and peak laying rate, and criteria for the suitability of the models. The Modified Compartmental model with lower values of AIC, BIC, MSE, MAE and MAPE was the most appropriate to describe the laying curve for the Dark Brown fighting hens. The Modified Compartmental model and the Logistic Curvilineear model were appropriate options to describe the laying curves for the Black fighting hens.

Collection and evaluation of the natural genetic resources of reishi mushroom is important in the research on medicinal mushrooms. This study aimed to evaluate growth and development characteristics of the newly collected reishi mushroom strain Ga8 in nature, serving basis for applying in production. The reishi Ga8 strain collected in Lang Son province was determined as Ganoderma lingzhi based on morphological characteristics and ITS sequence with 100% similarity in Genebank. The mycelia of the Ga8 strain were cultured on five nutrient media at four different temperature conditions. The results showed that the Ga8 strain grew best on Raper medium with an average mycelial growth rate of 5.56 mm/day. The optimum temperature for mycelial growth was 26°C ± 2. In addition, the Ga8 strain mycelium was also cultured on some master spawn substrates and cultivated. The master spawn substrate consisting of 99% boiled rice and 1% CaCO3 gave the best mycelial growth results, with an average growth rate of 5.72 mm/day. The culture substrate consisted of 87% corn cob, 8% wheat bran, 4% corn powder and 1% CaCO3 yielded highest mushroom biological efficiency of 6.87%

This study focused on isolating and optimizing the exopolysaccharide (EPS) recovery process from lactic acid bacteria (LAB) isolated from Vietnamese traditional fermented foods. Out of 33 isolated LAB strains, 21 showed EPS-producing ability. The optimal culture conditions for EPS biosynthesis were determined to be 30°C and pH 6.5. Trichloroacetic acid (TCA) and ethanol were used for protein removal and EPS precipitation. Strain L4.1 exhibited the highest EPS production. The optimal TCA concentration was 25%, the optimal culture broth : ethanol ratio was 1:1.5, and the optimal precipitation time for EPS recovery was 24 hours. The obtained EPS showed water solubility (30.04%) and free radical scavenging activity (65.87% at 1 mg/ml). This research identified optimal conditions for improving EPS recovery efficiency from LAB, opening potential applications in the future.

This study aimed to evaluate the effects of agricultural restructuring policies implemented over the past ten years (2014-2023) in Can Tho city. The “theory of change” method was used, whereby the policy contents, outputs and outcomes of the policy were arranged in order to see the systematicity and rationality of the local agricultural restructuring process. The results show that the policies have influenced agricultural economic growth in a positive direction as seen inthe outputs such as reducing the area of ​​ineffective rice land and the mean time increasing the area of ​​higher value vegetables and fruit trees.The agricultural land income increased significantl, and the proportion of trained agricultural workers increased. In particular, agricultural labor productivity has increased significantly with over 15%/year in recent years. The policy implication is that the locality needs to accelerate the agricultural restructuring economy towards product standardization, linkage between production and consumption under value chain approach and more public investment in agriculture for promoting the effectiveness of measures implemented in the agricultural restructuring process.

Community agricultural extension (CAE) is a new organizational model for agricultural extension piloted in Vietnam since 2022 under a government project. This study aimed to assess the status and key factors affecting the operations of CAE groups. This study assessed the current situation and identified key factors affecting the activities of CAE units using primary data from interviews with 26 leaders of CAE units in 13 piloted provinces and officers in charge of CAE activities in other 21 provinces. The findings reveal that CAE units had diverse components, involving both public and private sectors, and were more flexible and more service-oriented compared to traditional agricultural extension activities. However, CAE units faced difficulties and challenges in their operations, including policies, operating conditions, capacity, multi-component nature of the team as well as other external factors. Several recommendations to improve the performance of CAE units were proposed in the coming time.

Among the various methods used to assess economic viability, partial budget analysis (PBA) is considered a practical and effective tool for evaluating the economic efficiency of technical interventions in livestock production. PBA focuses on changes in four key economic components - increased income, reduced costs, increased costs, and decreased income - resulting from the implementation of a specific technical solution. By concentrating only on the elements affected by the intervention, PBA enables the estimation of net income change without requiring comprehensive data from the entire production system. This paper presents an overview of PBA, covering its concept, guiding principles, scope of application, and practical use in livestock research and production. Case study analyses illustrate PBA’s capacity to quantify the economic benefits of various technical improvements, including enhanced nutrition, genetic upgrades, housing system improvements, and veterinary interventions. The paper concludes that PBA is a straightforward yet powerful tool for evaluating the economic impact of technical advancements, thereby supporting more informed and efficient investment decisions in livestock production

Vegetables play an essential role in human health. However, issues related to the safety of vegetables cause concern among consumers, especially urban consumers in Vietnam who depend on the traditional vegetable distribution system. This paper presented the results of a review of some international and domestic theories and practices on urban consumers' access to safe vegetables. The study showed increasing worldwide access to and consumption of safe vegetables. The main factors affecting urban consumers' access and consumption of safe vegetables included awareness, education, price, income and freshness and deliciousness of the product, reputation of the supplier/seller, gender, age, convenience of the place of sale, distance to the place of purchase, health status... Based on the current situation and learning from experiences in some developed countries, the study proposes several solutions to increase urban consumers' access to safe vegetables in Vietnam.

This paper aimed to analyze the main barriers in pplication of information and communication technologies in agriculture. While information and communication technologies offer numerous benefits, the adoption remains low, particularly in developing countries including Vietnam. The results indicate that the adoption of information and communication technologies in agriculture is hindered by four main barriers: economic, technical, social, and institutional. Economic barriers relate to high investment costs, low income, and a lack of suitable economic models. Technical barriers include inadequate infrastructure, lack of appropriate applications and insufficient usage skills. Social barriers are linked to low educational levels, psychological factors, and limited community support. Institutional barriers involve the absence of supportive policies, lack of coordination among stakeholders, and insufficient training programs. To better promote the adoption of information and communication technologies in the Vietnamese agriculture sector, it is necessary to enhance the policy framework, improve farmers' capacities, upgrade information and communication technologies infrastructure, and develop effective business models.

Consumer cooperatives are a collective economic model, established to meet the needs of members by coordinating the purchase and sale of goods and services, thereby reducing costs and enhancing market competitiveness. This model originated in the 19th century with the success of the Rochdale cooperative in England and has since expanded and thrived globally. Throughout its development, consumer cooperatives have demonstrated their potential and inevitable growth trend in the market, becoming a significant component of the economies of many countries worldwide. They ensure member benefits and foster sustainable economic and social development. Using an overview research methodology and document analysis from various countries, this article aims to provide a comprehensive overview of theoretical issues related to consumer cooperatives. By doing so, the article contributes to building a theoretical foundation, supporting research, and proposing policies to promote the development of consumer cooperatives in Vietnam.

Tourism product development is one of the key factors in enhancing the competitiveness of Vietnam's tourism industry. However, theoretical studies on the tourism product development remain limited. Based on synthesized data and information from published research materials, articles, and textbooks, this paper aims to: (i) Provide an overview of the fundamental theoretical issues related to tourism product development; (ii) Summarize experiences in tourism product development from various countries around the world and localities in Vietnam; and (iii) Propose suggestions for tourism product development in Vietnam.

The article focuses on discussing several theoretical issues related to coastal agricultural development - a key area contributing to livelihood improvement, ecosystem protection, and the mitigation of negative impacts from climate change. The study employs a systematic literature review method combined with content and thematic analysis of scientific documents to clarify the concepts, roles, characteristics, key components, and factors influencing coastal agricultural economic development. The review of existing studies reveals that agricultural economic development in coastal areas should take advantage of regional ecosystem strengths to form an appropriate economic structure; select optimal production organization models; exploit natural resources sustainably with community participation; and enhance risk management capacity. Promoting agricultural economic development in coastal regions requires innovations in public investment and service provision, prioritization of infrastructure development, expansion of marine aquaculture, diversification of local livelihoods, integration of production with processing and market access, poverty reduction, as well as the effective application of climate-smart agriculture.