Asian Journal of Research in Agriculture and Forestry

Scale, Distribution and Forest Ownership of Poor Production Natural Evergreen Broadleaf Forest in the Former Gia Lai Province, Vietnam: Implications for Management

Nguyen Toan Thang — 2026-03-17

This study examines the former Gia Lai province as it existed prior to the July 2025 administrative merger with Binh Dinh province; all data and analyses refer exclusively to pre-merger boundaries. The former Gia Lai was located in the northern Central Highlands of Vietnam. With its diverse topography, including mountains, highlands, and valleys, the province holds significant potential for forestry development. This potential contributes to the local economy, creates employment opportunities, and supports social sustainability for ethnic communities in the region. This study provides an overview of the scale, distribution, and ownership of degraded natural evergreen broadleaf forests in the former Gia Lai, based on secondary data from the 2023 Vietnam national forest dataset (Decision No. 861/QD-BNN-KL, March 2024), analysed using descriptive statistical methods. The findings indicate that the total area of degraded natural evergreen broadleaf forests in the province is 90,736.57 hectares, distributed across 10,503 plots spanning all 17 districts. The forest area is allocated to seven categories of ownership: Communities (3,111.83 ha), Commune People's Committees (36,283.67 ha), Protection Forest Management Boards (37,315.75 ha), Forestry Companies (12,832.85 ha), Private Enterprises (143.51 ha), Armed Forces Units (910.81 ha), and Others (138.15 ha). Plots smaller than 0.5 ha are scattered throughout the province, presenting significant challenges for investment, management, and development efforts. The Commune People's Committees account for 40.00% of the total area of degraded natural evergreen broadleaf forests, despite not being specialised management entities. This institutional mismatch poses substantial difficulties for the effective management and development of these forest areas.

Characterization of Soil Properties in Basement Complex Landscapes of Orile-Igbon/Gambari, Oyo State, Nigeria

R. O. Teliat — 2026-03-31

This study assessed the physical and chemical properties of soils along a toposequence in the Orile-Igbon/Gambari area of Surulere Local Government Area, Oyo State, Nigeria. The toposequence was divided into upper, middle, and lower slope positions. Soil profile pits were excavated at each position, and samples were collected from all horizons for laboratory analysis. Physical properties evaluated included soil texture, structure, color, and horizon depth, while chemical properties comprised soil pH, exchangeable cations (Ca²⁺, Mg²⁺, K⁺, and Na⁺), effective cation exchange capacity (ECEC), organic carbon, total nitrogen, available phosphorus, and selected micronutrients.

Clear variations in soil physical characteristics occurred along the toposequence. Upper slope soils were light-colored, coarse-textured, and well-drained, with sandy clay to sandy clay loam textures and loose consistence. Middle slope soils exhibited darker surface horizons, finer textures, and increased clay accumulation in subsurface horizons, resulting in moderate water retention and nutrient-holding capacity. Lower slope soils showed darker horizons, finer textures, blocky structures, and evidence of waterlogging in deeper horizons, indicating restricted drainage and downslope material accumulation.

The soils were slightly acidic, with pH values of 5.0–5.7. Exchangeable calcium dominated the exchange complex, while magnesium, potassium, and sodium occurred at low levels. ECEC values indicated moderate nutrient-holding capacity. Organic carbon and total nitrogen contents were higher in surface horizons, particularly at the lower slope, due to organic matter accumulation. Available phosphorus varied and may limit crop growth in some horizons, while micronutrients were generally adequate. Overall, topography influenced soil properties, land-use planning, and sustainable agricultural production.

Disaggregated Agricultural Output and Economic Growth in Nigeria: Evidence from Distributional Regression Models

Olubisi L. Aako — 2026-03-31

The role of agriculture in spurring economic growth is often treated as a homogenous industry and modeled under limiting Gaussian conditions. These strategies blur heterogeneity in sub sectors of agriculture and do not reflect the asymmetric and volatile character of growth in resource-dependent economies such as Nigeria. This paper analyzes the impacts of disaggregated agricultural subsector output on the economic growth of Nigeria, and evaluates the ability of both the flexible distributional regression and the traditional normal multiple regression to make better inferences. The study models the real GDP using 60 quarterly data between 2010 and 2024 to determine its relationship between crop, livestock, forestry, and fisheries output. A Generalized Additive Model of Location, Scale and Shape (GAMLSS) is utilized to enable agricultural subsectors to not only influence the conditional mean of the growth, but the variance of the growth and the distributional shape. The performance of the models is compared to a reference Gaussian regression with the information criteria and diagnostic tests. The findings indicate that production of crops is an important driver of growth followed by forestry with a minor contribution. There are weak relationships between livestock and fisheries and aggregate output. The heterogeneous models that use heavy-tailed and asymmetric distributions perform better in comparison to the Gaussian specification, which indicates that the growth process in Nigeria is volatile and asymmetric. The study recommends renewed policy efforts targeted at agricultural modernization, infrastructural development, and sectoral stabilization to enhance agriculture’s contribution to economic growth.

Effects of Certification Standards Compliance on Burundi Coffee Marketing: A Case Study of COCOCA (2019-2023)

Silas NIMUBONA — 2026-04-02

Burundian coffee, widely recognized for its quality, faces significant challenges in the international market due to rising competition and quality requirements. Certification standards play a key role in improving agricultural practices and enhancing product value in the marketplace.

This study evaluates the effects of compliance with certification standards on the coffee marketing within Consortium of Coffee farmer’s cooperatives (COCOCA). Data were collected from 33 cooperatives, including 22 certified and 11 non-certified cooperatives, totaling 96 commercial green coffee sales contracts.

Based on data analysis, this paper examines the economic effects of voluntary certification schemes for coffee production and explores how certification schemes can be effective in encouraging more demands among buyers. Three major voluntary certification schemes are evaluated to identify the impacts on coffee price. The finding indicate that certification has a significant effect on coffee price, as shown by the F-value of 49.451 and the p-value < .05. This show a strong statistical evidence that the prices of certified coffee differ significantly from those of non-certified coffee. It indicated a substantial relationship between certification and price. The finding also show that a large majority of contracts for certified coffee come from abroad, indicating a strong international demand for certified coffee.

The study concludes that certification scheme significantly improves coffee marketing performance by increasing prices, enhancing market access, and strengthening international competitiveness. Certified cooperatives benefit from better access to markets, higher prices, and improve visibility for their products.

Effects of Rhizobial and Non-rhizobial Bacterial Isolates from Legume Root Nodules on the Growth of Maize (Zea mays L.) in Umudike, Abia State, Nigeria

N. Oji, Glory — 2026-04-03

The increasing dependence on chemical fertilizers in Nigeria has resulted in soil degradation, nutrient depletion, and environmental, necessitating sustainable alternatives like microbial biofertilizers. This study evaluated the effects of bacterial isolates obtained from the root nodules of selected leguminous plants on the growth of maize (Zea mays L.), contributing to sustainable agriculture and ensuring a healthier environment for future generations. Thirteen bacterial isolates were obtained from root nodules of beans, groundnut, soybean, sensitive plant and butterfly pea, using selective media including Yeast Extract Mannitol Agar, Ashby’s Mannitol Agar, Nitrogen-Free Malate Agar, and Nitrogen-Free BG-11 Agar. The isolates were morphologically and biochemically characterized, and formulated into liquid biofertilizers applied at 5.00ml and 10.00ml volumes to maize seedlings in a completely randomized pot experiment with untreated plants as control. Growth parameters including plant height, number of leaves, leaf area, internode length, and number of cobs were measured at two-week intervals up to 14 weeks. Data were analyzed using analysis of variance (ANOVA), and treatment means were separated using Duncan’s Multiple Range Test at 5% significant level. The results showed significant differences among treatments for all parameters measured. At 14 weeks, T3 (5.00ml) recorded the highest plant height (104.43 ± 25.06 cm), number of leaves (13.67 ± 2.05), leaf area (291.71 ± 33.12 cm²), internode length (5.37 ± 0.48 cm) and number of cobs (1.67 ± 0.40), all significantly exceeding the control values. The findings demonstrate that bacterial isolates from legume root nodules significantly enhanced maize growth and reproductive performance compared to the untreated control. However, molecular identification using 16SrRNA sequencing was not conducted and is recommended for accurate taxonomic confirmation The superior performance of the 5.00ml treatments, particularly T3, demonstrates the potential of indigenous bacterial biofertilizers as effective, eco-friendly inputs for sustainable maize production and reduced reliance on chemical fertilizers.

Microbial Inoculation as Plant Growth Promoter under Abiotic Stress Condition

Oke Kingsley Oyediran — 2026-04-01

Bio-inoculants comprising beneficial microorganisms such as plant growth-promoting rhizobacteria (PGPR), arbuscular mycorrhizal fungi (AMF), and their consortia offer a sustainable nature-based solution for enhancing plant-soil synergy under abiotic stress conditions. These microorganisms employ multiple mechanisms to bolster crop resilience against drought, salinity, heavy metals, and temperature extremes. Key mechanisms include enhanced nutrient mobilization through nitrogen fixation, phosphorus solubilization, potassium mobilization, and siderophore-mediated iron chelation that improve nutrient availability under stress. Phytohormone modulation via microbial production of indole-3-acetic acid (IAA), gibberellins, and cytokinins modifies root architecture and promotes growth, while ACC deaminase activity reduces stress-induced ethylene levels, delaying senescence and maintaining root development. Osmolyte accumulation including proline, trehalose, and glycine betaine maintains cellular turgor and protects membrane integrity, while activation of antioxidant enzymes (SOD, CAT, APX, GR) scavenges reactive oxygen species, reducing oxidative damage. Microbial consortia consistently outperform single strains through synergistic interactions and functional complementarity. Field applications demonstrate significant yield improvements under stress: 32.9% biomass increase in salt-stressed rice, 36% shoot dry weight enhancement in metal-contaminated soils, and successful large-scale adoption in Brazil where 86% of soybean growers use inoculants. Transitioning to microbiome-aware farming systems requires integrated research, supportive policies, and farmer engagement to realize the full potential of bio-inoculants for climate-resilient agriculture.