Vol. 23 No. 8 (2025): Tạp chí Khoa học Nông nghiệp Việt Nam

The study on the effect of nitrogen and potassium fertilizer levels on the growth, yield of aloe vera (Aloe vera L.) in the sandy soil ofBinh Thuan, from June to November 2023. The two-factor experiment was arranged in a Split - plot design with three replications. The main factor (main plot) was three potassium levels including 85; 95 and 105kg K2O ha-1 year-1 and the secondary factor (main plot) was three potassium levels including 85; 95 and 105kg K2O ha-1 year-1. The secondary factor (sub plot) was five nitrogen fertilizer levels including 130; 150; 170; 190 and 210kg N ha-1 year-1 .The basis application was 30 tons of farmyard manure + 160kg P2O5 ha-1 year-1 . The research results showed that different amounts of nitrogen and potassium had a clear impact on plant height, leaf length, number of leaves/plant, yield and yield components. Aloe vera plants were fertilized with 190kg N combined with 105kg K2O ha-1 year-1 on 30 tons of farmyard manure and 160kg P2O5 ha-1 year-1 for the highest leaf length (52.3cm) and leaf yield (35.5 tons/ha).

Cassava mosaic disease is the most serious disease affecting cassava worldwide and its is caused by at least 11 viruses belonging to the genus Begomovirus. In Vietnam, cassava mosaic disease was first reported in Tay Ninh province in 2017 and rapidly spread throughout the country. The objectives of this study were to assess the status of cassava mosaic disease in major cassava-growing regions, identify epidemiological factors influencing the disease, and confirm its causal agent. Field surveys conducted in 2022 showed that cassava mosaic disease was present in 10 out of 12 surveyed provinces, with an average disease prevalence of 70.4%. The average disease incidence (DI), disease severity index (DSI), and adult whitefly (Bemisia tabaci) density were 75.4%, 2.80, and 2.51 individuals per plant, respectively. Statistical analyses revealed that: (i) cassava variety determined DI, DSI, and whitefly density; (ii) plant age influenced DSI; (iii) plants propagated from infected cuttings had higher DSI than those infected via whiteflies; (iv) adult whitefly density had a slight effect on DI but no effect on DSI. PCR testing of 507 cassava leaf samples and sequencing of 15 virus isolates confirmed that Sri Lankan cassava mosaic virus (Begomovirus stanleyi) was the sole causal agent of cassava mosaic disease in Vietnam at the time of investigation.

This study was conducted to determine the species composition, external morphological characteristics, and distribution of freshwater snails on Bach Long Vi Island. A total of 254 snail specimens were collected from freshwater habitats across the island in September 2024. Seven species of freshwater snails were identified, belonging to six genera, six families, and two subclasses, including three exotic species (Pomacea canaliculata, P. maculata, Physella acuta) and four native species (Melanoides tuberculata, Angulyagra boettgeri, Orientogalba viridis, Gyraulus convexiusculus). This is the first checklist of freshwater snails from Bach Long Vi Island. None of the recorded species are listed in the 2024 Vietnam Red Data Book as endangered, rare, or threatened. The study provides scientific data on the taxonomy, distribution, and ecological characteristics of freshwater snails on the island, and proposes preliminary management measures to help control and mitigate the impacts of invasive species.

The emergence of recombinant ASFV strains with genetic characteristics of both genotype I and genotype II (rASFV I/II) in Vietnam since 2023 poses a major challenge for disease control, especially given the limited protective efficacy of current vaccines. This study aimed to evaluate the virulence and transmission potential of the recombinant ASFV strain VNUA/rASFV/HD1/23 using an experimental infection model by intranasal inoculation and natural contact exposure. The results showed that pigs directly inoculated with the virus developed acute clinical disease with a 100% mortality rate (3/3). Death occurred between the 5th and 12th day after infection (average 8 days). In the contact group, the first pig died on the 14th day after exposure. Typical clinical signs included high fever (> 40°C), anorexia, lethargy, and restricted mobility. Gross pathological findings in the infected pigs were consistent with acute ASF, characterised by splenomegaly with friability, haemorrhagic lymph nodes, and marked haemorrhage and congestion in the lungs, kidneys, intestines, and stomach. These results confirm the high virulence and transmissibility of the rASFV I/II strain.

This study evaluated the post-harvest sand depuration efficiency of market-sized Meretrix lyrata clams using a recirculating aquaculture system (RAS). A total of three laboratory experiments and 17 pilot-scale trials were conducted. The laboratory trials, each lasting 48 hours, independently examined the effects of three factors: microalgal (Chaetoceros gracilis) concentration (0, 11 × 103, 22 × 103, 33 × 103 cells/ml), feeding frequency (every 3, 6, 9, and 12 hours), and clam stocking density (18, 54, 90, 126 kg/m3). Assessing parameters included survival rate, proportion of clams containing sand, and clearance rate. The optimal microalgae concentration for depuration was determined to be 22 ×103 cells/ml. Feeding every 3 hours resulted in the highest sand removal efficiency; however, a 6-hour interval was adopted in subsequent trials to improve operational feasibility. The best performance in terms of sand removal and clearance rate was observed at a density of 18 kg/m3. Pilot-scale trials conducted under commercial conditions, with densities ranging from 170 to 380 kg/m3, demonstrated that RAS-based depuration was more effective than conventional aerated soaking when the treatment duration exceeded 24 hours. These findings highlight the potential of RAS technology to enhance clam depuration efficiency and provide a foundation for an optimized system aimed at improving meat yield recovery in future applications.

This study was conducted to determine the appropriate stocking density of giant freshwater prawns in the combined farming model with black apple snails. The experiment consisted of 4 treatments and each treatment had 3 replications with different prawn densities: no prawn and prawn densities of 3, 5 and 7 ind./m2. Snails were stocked at a density of 100 snails/m2. After 90 days of culture, the survival rate of prawns reached 100% and did not differ between treatments (P >0.05), However, the survival rate of snails decreased significantly when increasing the density of prawns in the system. If cultured alone, the snails obtained a higher weight (3.20 ± 0.16g) and shell height (24.76 ± 0.26mm) than the treatments of culture with prawns. The highest yield of snails was obtained when cultured without prawn, but there was no significant difference (P >0.05) when cultured with 3 prawns/m2. The research results showed that in the apple snail culture system (density of 100 snails/m2), co-culture with giant freshwater prawns is possible at a density of 3 prawns/m2.

The study assessed the current situation and proposes solutions to improve the operational efficiency of the Hanoi City Land Registration Office. The research team randomly selected a total of 100 land users who came to work at the Land Registration Office and 30 officers working at the Land Registration Office and related agencies were randomly selected. The results show that in terms of granting land use right certificates to organizations, households, and individuals, 146,934 records have been granted. In terms of land change registration, 137,601 records have been granted. In terms of secured transactions, 95,540 records of mortgages using land use rights have been resolved; 62,072 records of mortgage cancelations; and 4,476 records of changes in mortgage content. The preliminary investigation results show that the 6/9 criteria are rated at a very high level, and 3/9 criteria are rated at a high level. According to the results of the land user survey, the 6/9 criteria were rated at a very high level, and the remaining 3/9 criteria were rated at a high level. From there, it is proposed to implement synchronous solutions to mechanisms and policies; improve the quality of human resources; invest in upgrading facilities; finance; and strengthen coordination with relevant parties.

This study aimed to propose solutions for developing and scaling-up climate-smart agriculture (CSA) models appropriate to Giao Thuy district, Nam Dinh province - a coastal area heavily affected by climate change. Data were collected through a survey of 180 farming households, focus group discussions (FGDs), and participatory on-farm experiments. Three promising farming models were identified: crop rotation of hybrid melons and vegetables, polyculture of red tilapia and white-leg shrimp in freshwater, and intensive white-leg shrimp farming in brackish water. The experimental models, combined with technical interventions, showed higher economic efficiency than conventional models, while improving soil and water quality and enhancing resilience to extreme weather events. The study proposed a three-phase CSA scaling roadmap, initially targeting households with farming experience and financial capacity, then expanding to more vulnerable groups. Supporting solutions include technical interventions (soil, water, and seed management), market linkages, credit access, and integration of CSA into local planning. The findings confirmed that CSA is a feasible approach to improve livelihoods and climate resilience in Giao Thuy district.

This study evaluated projected changes in precipitation, streamflow, and flooding in the Pho Day River Basin by the end of the 21st century under the high-emission scenario SSP5-8.5. An integrated modeling approach combining the Weather Research and Forecasting (WRF) model and the Rainfall-Runoff Inundation (RRI) model was employed, using observational data from 56 meteorological stations, JRA-25/JCDAS reanalysis data, and climate projections from the CMIP6 GCMs EC-Earth3 and HadGEM3-GC31-MM. Validation results showed that WRF accurately captured meteorological conditions for the 2003-2022 period, while RRI reliably simulated the 2019 flood event, confirming the models’ suitability for hydrometeorological assessments. The findings revealed a significant increase in summer (JJA) precipitation by 2080-2099, particularly in the northern and northeastern upstream regions. This leads to pronounced increases in streamflow and flood peaks, especially in downstream areas, resulting in more severe flooding characterized by greater depth and spatial extent,most notably under extreme climate scenarios. Streamflow during the rainy season may rise by 8.8% to 15.6%, with peak flood depths increasing by 1-3 meters. These increases are concentrated toward the end of the wet season, underscoring the considerable impact of climate change on future flood risks.

The experiment aimed to determine the effects of treatment conditions (aerobic, anaerobic) and seasons (Spring, Summer) on the composting process of industrial livestock waste (cow, chicken, pig). The wastes were co-composted with biochar at a ratio of 9:1 (v/v) under different conditions to analyze the changes during composting. The results showed that aerobic treatment conditions were suitable for all types of waste. The anaerobic composting method, which produced compost product with higher nutritional and organic content but carried harmful microorganisms (E. coli, Salmonella) exceeding the standard. After 30 days of composting, cow manure possessed highest organic content (46.54-47.67%) and a total NPK content of 4.04-4.43%, but C/N ratio was higher than the regulation (> 12). In contrast, chicken waste compost possessed lowest organic matter content (36.46-37.59%), but highest total NPK content (5.05-5.44%) and met the standard for C/N ratio. In addition, pig waste compost possessed an average organic matter content and lowest total NPK content value. In both Spring and Summer, chicken waste and biochar, which were treated aerobically, had NPK nutrient content, pH, C/N ratio and heavy metal content (As, Pb, Cd, Hg) meeting the organic fertilizer standards according to QCVN 01-189-2019.

This study analyzed the consequense of large-scale agricultural investment program on the livelihood strategies of the ethnic minority communities in Vietnam’s Northwest region based on integrated theoretical framework that combines sustainable livelihoods, livelihood pathways, and political economy in agriculture, using the case study of rubber cultivation program in Điện Biên province. Based on surveys with 205 ethnic minority households, 15 local government officials, and 5 company representatives, the research revealed that following land lnad allocation to state rubber farm ethnic minority households deliberately shifted their livelihoods from subsistence-based farming to a diversification of livelihood strategies. These strategies were shaped by the livelihood assets available to each ethnic group, as well as their socio-political relationships and market conditions. The study findings suggested several policy implications for improving the livelihoods of ethnic minority populations, i.e. designing large-scale agricultural investment programs that are ecologically and socially appropriate for the Northwest region; protecting land use rights and promoting sustainable livelihoods for ethnic minorities; and identifying and supporting vulnerable population groups during the investment process.

The application of artificial intelligence in veterinary medicine is expected to support the development of this field in many aspects. Launched by OpenAI in November 2022, ChatGPT is the fastest-growing artificial intelligence (AI) application with users as a learning tool in recent times. In veterinary medicine, ChatGPT is a virtual assistant that supports clinical diagnosis, training, and scientific research in the animal health care industry based on information available on the internet. In addition to the advantages, challenges, and limitations of ChatGPT also need to be considered and evaluated such as reliability, copyright issues, and user personal information security issues. Therefore, this review briefly discusses ChatGPT with a focus on its advantages and limitations, with the hope that veterinary students and veterinarians can exploit the power of ChatGPT most effectively, contributing to the development of this field in today's digital transformation society.

This paper provides an overview of the role of online business in the development of household economies in Vietnam in the context of digital transformation. The study employs methods of collecting, synthesizing, and analyzing secondary data from academic journals, scientific articles, and reports issued by domestic and international organizations. The results showed that online business has become a growing trend, helping households expand markets, reach customers more effectively, reduce operating costs, increase income, and create additional employment opportunities. It examines the relationship between online business and household economic development through various aspects, including market expansion, cost optimization, enhanced competitiveness, and job creation. The research also identifies several opportunities to promote the household economic development such as the rapid growth of digital platforms, supportive government policies, and increasingly improved digital infrastructure. However, challenges remain, including limited digital skills, high advertising costs, and intense competition from larger enterprises. Based on these findings, the article proposes solutions to improve the effectiveness of online business, thereby contributing to the modernization and sustainable development of the household economy.

Streptococcus iniae is a highly pathogenic microorganism that poses significant economic threats to marine aquaculture, notably impacting commercially valuable species such as snubnose pompano, seabass, groupers, and snappers. The recent emergence of new infection cases in both farmed and wild fish populations, domestically and internationally, underscores the urgent necessity for comprehensive data collection for the development of effective disease management strategies. Such measures are vital to reducing economic losses in Vietnam’s marine fisheries sector. This review explores the mechanisms of infection, virulence factors, antibiotic resistance, and the current approaches to disease control in marine fish affected by S. iniae. The review highlights ongoing research and practical applications involving vaccines, probiotics, and botanical products aimed at enhancing immunological defences and resistance against this pathogen. Furthermore, the review discusses future prospects and research directions pertinent to S. iniae infections in Vietnamese marine fish, thereby supporting the advancement of sustainable aquaculture practices and effective disease management.