Management of heavy metals in rice (Oryza sativa) soils by silicon rich biochar materials

Multiple heavy metals have contaminated soils with a combination of ecological consequences that make soil remediation more challenging. An experiment was conducted during 2022–23 at University of Agriculture and Forestry, Hue University, Hue city, Vietnam to evaluate the potential of silicon rich biochar from rice (Oryza sativa L.) husk and peanut shell in the remediation of heavy metals (Cd, Pb, Cu and Zn) present in rice soils of central Vietnam. A total of 20 samples of rice soil were taken from two distinct locations, Quang Tho commune and Thuy Phuong ward, Thua Thien Hue province, Central Vietnam to measure the quantity of heavy metals and evaluate the level of pollution. Silicon is a beneficial element and its external application as fertilizer seems impractical. Therefore, in this study, the effects of different silicon-rich materials [rice husk biochar (RHB) and peanut shell biochar (PSB)] at 6 different rates (0, 1, 2, 3, 4 and 5%) were determined in reducing heavy metal (Cd and Pb). The mean concentrations of Cd, Pb, Cu and Zn in soil samples ranged between 0.56–22.14 mg/kg; 19.48–81.30 mg/kg; 23.26–48.54 mg/kg and 28.47–55.12 mg/kg, respectively. Cd and Pb toxicity in rice soil samples was greater in Thuy Phuong ward than the average shale values. Considering the pollution load index (PLI), a total of 6 sites in Thuy Phuong ward had values >1.0 indicating pollution load in the respective sites, and Cd, Pb were the major contaminants in soils of the study area. The addition of silicon-rich materials decreased the contents of Cd and Pb in rice soils with adsorption efficiency from 22.83–38.54% and 30.69–31.53% in rice husk biochar (RHB); 20.47–29.55% and 26.77–27.87% in peanut shell biochar (PSB), respectively. Thus, RHB could be more effective to remediate soils contaminated with heavy metals when compared to other silicon-rich materials

Utilisation agricole de plantes aquatiques, notamment en tant qu'amendement des sols, dans la province de Thua Thien Hue, Centre Vietnam. 1. Inventaire, abondance et caractérisation chimique des plantes aquatiques disponibles localement

Agricultura Use of Aquatic Plants, mainly as Soil Amendment, in the Thua Thien Hue Province, Central Vietnam. 1. Inventory, Abundance and Chemical Characterization of Collected Plants. The use of aquatic plants for various purposes, and notably as organic amendment for sandy soils with low inherent fertility is a frequent empirical practice in Central Vietnam. In the Thua Thien Hue Province, the Tam Giang lagoon covering 22,000 ha represents a source of exogenous biomass potentially important for agriculture. The present study makes an inventory of the submerged macrophytes and the algae occurring in the lagoon during the period of February-April 2005. Twelve species of macrophytes (belonging to the Potamogetonaceae, Najadaceae, Cymodoceaceae, Hydrocharitaceae, Ceratophyllaceae, and Haloragaceae families) and five of algae (belonging to the Ulvaceae, Cladophoraceae, Characeae, and Gracilariaceae families) were identified. Their abundance varies significantly following species and location in the lagoon. Indeed, the salt concentration, the water depth and the type of sediments in which the macrophytes are anchored are submitted to large variations depending on position in the lagoon. The highest values of fresh biomass measured for monospecific vegetal mats were observed for Vallisneria spiralis (3.1 kg.m-2), Najas indica (2.9 kg.m-2), Halodule tridentata (2.5 kg.m-2) and Cymodoceae rotundata (2.3 kg.m-2). The concentrations of main elements were determined in samples of all plant species. In the macrophytes, the following ranges of element concentrations (in % of dry matter) were found: N 1.0 to 3.5; P 0.08 to 0.45; K 1.0 to 4.2; Mg 0.3 to 1.4; Ca 0.7 to 2.8; Na 0.7 to 7.6. These variations indicate that the fertilization capacity of aquatic plants when they are used as soil amendment can vary to a large extent according to the species. Even more contrasted element concentrations were found for the algae. The Na concentrations in the collected plants can be partly explained by the salinity level met in the sampling areas

The impact of brand positioning and knowledge on attitude towards brand and purchase intention: A study of organic rice in Ho Chi Minh City

The purpose of this study is to measure the effectiveness of factors of brand, including Brand Positioning, Brand Knowledge, Attitude towards Organic Rice Brand, and Organic Rice Purchase Intention. The survey was conducted with a sample of 224 consumers shopping at four organic rice shops in Ho Chi Minh City. The research was performed by quantitative research methods: Cronbach's Alpha Reliability Analysis, Exploratory Factor Analysis (EFA), Confirm Factor Analysis (CFA), and Structural Equation Modeling (SEM). The research results were conducted in two direct models and the indirect models in which the indirect model was supported. This means that brand positioning and brand knowledge had no direct impact on the Intention to buy organic rice, but only an indirect one through the consumer attitude towards the organic rice brand

ĐÁNH GIÁ THỰC TRẠNG CANH TÁC DỪA TẠI ĐẢO PHÚ QUỐC, TỈNH KIÊN GIANG

Coconut trees (Cocos nucifera L.)  are a popular crop on more than 30,000 islands around the world, with many uses and livelihood values for farmers. The study was conducted to evaluate the current status of coconut farming on Phu Quoc Island by interviewing farmer households. The results showed that coconut trees were planted in Cua Duong and Cua Can communes with growing areas ranging from 0.2 to 0.8 hectares per household, mainly in the form of specialised cultivation with two popular coconut varieties which were oil coconut and drinking coconut. Coconut oil varieties ranged in age from 1 to 15 years, flowering time from 4.0 to 5.0 years after planting, and yield from 40 to 60 fruits per tree per year. Drinking coconut varieties were less than 10 years old; flowering time was from 3.0 to 4.0 years after planting; and yielding was from 50 to 100 fruits per tree per year. The form of fruit sales on Phu Quoc Island was mainly drinking coconuts purchased, with harvests ranging from 10 to 15 times per year. The investment cost for coconut gardens of households the business period mainly under 10 millions VND and average incomes under 20 millions VND per hectare per year, respectively.Cây dừa (Cocos nucifera L.) là cây trồng quan trọng ở các vùng biển đảo, được trồng phổ biến ở hơn 30.000 hòn đảo trên thế giới với nhiều giá trị sử dụng và là sinh kế của người nông dân. Nghiên cứu được thực hiện nhằm đánh giá thực trạng canh tác dừa tại đảo Phú Quốc, tỉnh Kiên Giang bằng phương pháp thu thập số liệu thứ cấp và phỏng vấn nông hộ. Kết quả cho thấy, cây dừa được trồng tập trung tại xã Cửa Dương và xã Cửa Cạn với diện tích từ 0,2 đến 0,8 ha/hộ, chủ yếu là hình thức chuyên canh với hai nhóm giống dừa phổ biến là lấy dầu và uống nước. Giống dừa lấy dầu có độ tuổi từ 1 đến 15 năm, thời gian ra hoa từ 4,0 đến 5,0 năm sau trồng và năng suất từ 40 đến 60 quả/cây/năm. Giống dừa uống nước có độ tuổi dưới 10 năm, thời gian ra hoa từ 3,0 đến 4,0 năm sau trồng và năng suất từ 50 đến 100 quả/cây/năm. Hình thức bán quả dừa tại đảo Phú Quốc chủ yếu là uống nước với số lần thu hoạch từ 10 đến 15 lần/năm. Chi phí chăm sóc vườn dừa trong thời kỳ kinh doanh chủ yếu dưới 10 triệu đồng/ha/năm với lợi nhuận đa số dưới 20 triệu đồng/ha/năm

THỰC TRẠNG CANH TÁC DỪA TẠI TỈNH BẾN TRE, VIỆT NAM

Coconut is an important cash crop in Ben Tre Province, Vietnam, which has a lot of value. This study aimed to determine the current status of coconut cultivation in Ben Tre province through secondary data collected from the Ben Tre Provincal Statistical Office as well as primary data provided by 150 farmers in five coconut cultivated districts consisting of Chau Thanh, Giong Trom, Ba Tri, Thanh Phu, and Binh Dai via participatory interview method. The results showed that coconut planting and harvesting areas in Ben Tre province have been a significant increase over the period from 2012 to 2022, with production increasing by 1.6 times, reaching 686,279 tonnes in 2022. The predominant coconut cultivated method was specialised farming, with most households using tall coconut varieties. Planting density ranged from 160 to 240 trees per hectare. Flowering of the coconut plants was within 3 to 6 years of planting. Fertilization application was 4 to 6 times year-1 during the business period. Besides, insect pests and diseases on the coconut plants had been controlled by pesticides with 3 to 6 times per year. Coconut fruit yields were depended on variety and cultivation techniques, averaging 80 to 100 fruits tree-1 year-1 and 40 to 80 fruits tree-1 year-1 for dwarf and tall coconuts, respectively. The investment cost for coconut gardens ranged from 10 to 30 million VND hectare-1 year-1, with average incomes of 30 to 100 million VND hectare-1 year-1, yielding profits of 30 to 60 million VND hectare-1 year-1.Cây dừa là cây trồng quan trọng của tỉnh Bến Tre có nhiều giá trị sử dụng. Nghiên cứu này nhằm đánh giá thực trạng canh tác dừa tại tỉnh Bến Tre dựa trên số liệu thứ cấp từ Cục Thống kê tỉnh Bến Tre và số liệu sơ cấp thông qua phỏng vấn 150 hộ trồng dừa tại 5 huyện gồm Châu Thành, Giồng Trôm, Ba Tri, Thạnh Phú và Bình Đại. Kết quả cho thấy, diện tích trồng và thu hoạch dừa tại tỉnh Bến Tre có xu hướng tăng mạnh trong 10 năm (2012–2022), sản lượng tăng gấp 1,6 lần và đạt 686.279 tấn vào năm 2022. Hình thức canh tác dừa chủ yếu chuyên canh, phần lớn các hộ sử dụng giống dừa cao, mật độ trồng dao động 160–240 cây/ha, cây dừa bắt đầu ra hoa sau 3–6 năm trồng, số lần bón phân trong thời kỳ kinh doanh là 4–6 lần/năm, quản lý sâu bệnh hại dừa chủ yếu bằng thuốc bảo vệ thực vật với 3–6 lần phun/năm. Năng suất dừa phụ thuộc vào giống và kỹ thuật canh tác, trung bình 80–100 quả/cây/năm đối với dừa lùn và 40–80 quả/cây/năm đối với dừa cao. Chi phí đầu tư cho vườn dừa 10–30 triệu đồng/ha/năm, thu nhập bình quân 30–100 triệu đồng/ha/năm và đem lại lợi nhuận 30–60 triệu đồng/ha/năm

Farming systems in the sandy area of the Thua Thien Hue Province, Central Vietnam, survey of socio-economic situation and constraints identified by farmers

peer reviewe

Состояние провоспалительного цитокинового звена у больных с нестабильной стенокарадией и сахарным диабетом 2-го типа в зависимости от функционального класса хронической сердечной недостаточности

Проанализировано состояние провоспалительного звена цитокинов у больных с нестабильной стенокардией (НС) и сопутствующим сахарным диабетом (СД) 2−го типа в зависимости от функционального класса хронической сердечной недостаточности (ХСН). Нарастание проявлений сердечной декомпенсации у больных с НС и СД 2−го типа ассоциируется с высокой активностью провоспалительного цитокинового звена, представленного фактором некроза опухолей−α и интерлейкином−6. Повышение функционального класса ХСН характеризуется увеличением инсулинорезистентности у больных с НС и СД 2−го типа.Проаналізовано стан прозапальної ланки цитокінів у хворих із нестабільною стенокардією (НС) та супутнім цукровим діабетом (ЦД) 2−го типу залежно від функціонального класу хронічної серцевої недостатності (ХСН). Наростання проявів серцевої декомпенсації у хворих із НС та СД 2−го типу асоціюється з високою активністю прозапальної цитокінової ланки, представленої фактором некрозу пухлин−α та інтерлейкіном−6. Підвищення функціонального класу ХСН характеризується зростанням інсулінорезистентності у хворих із НС та ЦД 2−го типу.The state of pro−inflammatory cytokines in patients with unstable angina (UA) and associated type 2 diabetes mellitus (DM) was analyzed depending on the functional class of chronic heart failure (CHF). The increase in manifestations of cardiac decompensation in patients with UA and type 2 DM is associated with high activity of pro−inflammatory cytokine level represented by tumor necrosis factor−β and interleukin−6. Increase of functional class of CHF is characterized by increased insulin resistance in patients with UA and type 2 DM

ĐẶC ĐIỂM HÌNH THÁI VÀ ĐẶC ĐIỂM VI HỌC CỦA LOÀI BA KÍCH TÍM (Morinda officinalis How.) THU HÁI TẠI TỈNH THỪA THIÊN HUẾ

Morinda officinalis How. is a medicinal plant that has been studied and used for a long time. Previous studies on M. officinalis primarily focused on the source in the northern provinces of Vietnam. This study is the first one on the botanical characteristics, including morphology, anatomy, and powder microscopy of M. officinalis in Thua Thien Hue province. Morphological and microscopic characteristics were determined by comparing the shape and double-staining and observing under a microscope through 10× and 40× objective lenses. The results show the similarities and differences of M. officinalis in Thua Thien Hue and other regions of Vietnam. Particularly, the root of M. officinalis in Thua Thien Hue has a higher percentage of usable parts than other M. officinalis species in northern regions. Furthermore, the results of the study provide scientific data for learning and investigating the morphological and microscopic characteristics of M. officinalis in Thua Thien Hue.Ba kích tím (Morinda officinalis How.) là một loài dược liệu quý được nghiên cứu và sử dụng từ rất lâu đời. Các nghiên cứu về Ba kích tím trước đây chủ yếu tập trung vào nguồn giống thu hái tại các tỉnh phía Bắc của Việt Nam. Nghiên cứu này là công trình đầu tiên về đặc điểm thực vật bao gồm hình thái, vi phẫu và soi bột của cây Ba kích tím được thu hái tại môi trường tự nhiên của tỉnh Thừa Thiên Huế. Đặc điểm hình thái và đặc điểm vi học được nghiên cứu bằng phương pháp so sánh hình thái và nhuộm kép và quan sát dưới kính hiển vi qua vật kính 10× và 40×. Kết quả nghiên cứu cho thấy sự tương đồng và khác biệt chính về đặc điểm thực vật của cây Ba kích tím giữa Thừa Thiên Huế và các vùng miền khác ở Việt Nam. Đặc biệt, rễ củ Ba kích tím tại Thừa Thiên Huế có tỷ lệ bộ phận sử dụng nhiều hơn so với các loài Ba kích tím tại khu vực phía Bắc. Kết quả của bài báo góp phần cung cấp dữ liệu khoa học cho học tập và nghiên cứu về đặc điểm hình thái và vi học của loài Ba kích tím ở Thừa Thiên Huế

Logging intensity drives variability in carbon stocks in lowland forests in Vietnam

Forest degradation in the tropics is generating large carbon (C) emissions. In tropical Asia, logging is the main driver of forest degradation. For effective implementation of REDD+ projects in logged forests in Southeast Asia, the impacts of logging on forest C stocks need to be assessed. Here, we assess C stocks in logged lowland forests in central Vietnam and explore correlations between logging intensity, soil, topography and living aboveground carbon (AGC) stocks. We present an approach to estimate historical logging intensities for the prevalent situation when complete records on logging history are unavailable. Landsat analysis and participatory mapping were used to quantify the density of historical disturbances, used as a proxy of logging intensities in the area. Carbon in AGC, dead wood, belowground carbon (BGC) and soil (SOC) was measured in twenty-four 0.25 ha plots that vary in logging intensity, and data on recent logging, soil properties, elevation and slope were also collected. Heavily logged forests stored only half the amount of AGC of stems ≥10 cm dbh as lightly logged forests, mainly due to a reduction in the number of large (≥60 cm dbh) trees. Carbon in AGC of small trees (5–10 cm dbh), dead wood and BGC comprised only small fractions of total C stocks, while SOC in the topsoil of 0–30 cm depth stored ~50% of total C stocks. Combining logging intensities with soil and topographic data showed that logging intensity was the main factor explaining the variability in AGC. Our research shows large reductions in AGC in medium and heavily logged forests. It highlights the critical importance of conserving big trees to maintain high forest C stocks and accounting for SOC in total C stock estimates

Risk Factors of Streptococcus suis Infection in Vietnam. A Case-Control Study

Background: Streptococcus suis infection, an emerging zoonosis, is an increasing public health problem across South East Asia and the most common cause of acute bacterial meningitis in adults in Vietnam. Little is known of the risk factors underlying the disease. Methods and Findings: A case-control study with appropriate hospital and matched community controls for each patient was conducted between May 2006 and June 2009. Potential risk factors were assessed using a standardized questionnaire and investigation of throat and rectal S. suis carriage in cases, controls and their pigs, using real-time PCR and culture of swab samples. We recruited 101 cases of S. suis meningitis, 303 hospital controls and 300 community controls. By multivariate analysis, risk factors identified for S. suis infection as compared to either control group included eating "high risk" dishes, including such dishes as undercooked pig blood and pig intestine (OR1 = 2.22; 95% CI = [1.15-4.28] and OR2 = 4.44; 95% CI = [2.15-9.15]), occupations related to pigs (OR1 = 3.84; 95% CI = [1.32-11.11] and OR2 = 5.52; 95% CI = [1.49-20.39]), and exposures to pigs or pork in the presence of skin injuries (OR1 = 7.48; 95% CI = [1.97-28.44] and OR2 = 15.96; 95% CI = [2.97-85.72]). S. suis specific DNA was detected in rectal and throat swabs of 6 patients and was cultured from 2 rectal samples, but was not detected in such samples of 1522 healthy individuals or patients without S. suis infection. Conclusions: This case control study, the largest prospective epidemiological assessment of this disease, has identified the most important risk factors associated with S. suis bacterial meningitis to be eating 'high risk' dishes popular in parts of Asia, occupational exposure to pigs and pig products, and preparation of pork in the presence of skin lesions. These risk factors can be addressed in public health campaigns aimed at preventing S. suis infectio