Email: vuky124@gmail.com

Our study results on greenhouse gas (GHG) emissions from intercropping systems in Robusta coffee farms in Dak Lak province showed that synthetic fertilizer played the role of the absolute dominant driver of GHG emissions, specifically acting as the central “emission hotspot” that overshadows all other farm inputs.

1. The Dominant Source of Emissions: Synthetic nitrogen fertilizer was identified as the single largest contributor to the carbon footprint of coffee farming. Across all farm types surveyed, the use of inorganic fertilizers accounted for approximately 71% of total emissions. When analyzed specifically within intercropping systems, this figure ranged between 75.8% and 81.8% of total emissions, rendering all other sources, such as irrigation, lime, and fossil fuels, minor in comparison[1].

To contextualize its dominance, emissions from synthetic nitrogen fertilizer (2,300 to 4,340 kg CO₂e/ha) were significantly higher than those from urea, phosphorus, and potassium fertilizers. It also outweighed emissions from irrigation (~8%), lime (~6%), and plant protection products (~4.8%)

2. The Mechanism of Emissions: The “hotspot” status of synthetic nitrogen is driven by the biological and chemical processes that convert applied nitrogen into nitrous oxide (N₂​O), a gas with a Global Warming Potential 273 times that of CO₂[2]. Of which:

Direct Emissions: When synthetic nitrogen fertilizers are added to the soil, they increase the available nitrogen for microbial processes. This enhances nitrification of the oxidation of ammonium to nitrate) and denitrification (the reduction of nitrate to nitrogen gas), both of which are released directly as by-products from the soil[3].

Indirect Emissions: Synthetic nitrogen also drives emissions off-site through two pathways:

• Volatilization: a fraction of the applied nitrogen vaporizes as ammonia (NH₃) and nitrogen oxides (NO_x), which deposit elsewhere and convert to N₂​O.
• Leaching and Runoff: Nitrogen that is not taken up by plants (mainly as nitrate NO₃-) leaches into groundwater or runs off into surface waters, where it undergoes transformation into rivers and estuaries. The default factor for the fraction of nitrogen lost to leaching in wet climates is 0.24 (24% of applied N)

3. Drivers of High Emissions: the role of nitrogen as a hotspot is exacerbated by specific farming behaviors and environmental factors.

Overuse: farmers in the Central Highlands frequently apply significantly more nitrogen than recommended, up to 300% more in some cases, believing that high inputs guarantee high outputs.

Intercropping Demands: The integration of high-value crops like durian and black pepper has led farmers to increase agrochemical inputs further. Systems including durian were noted as the most input-intensive, often disregarding the actual nutrient demands of the mixed crops in favor of maximizing yield.

Habit over Science: The application of fertilizers is often driven by habit rather than scientific assessment of soil or crop needs.

4. Comparison with other activities: Understanding the scale of the nitrogen “hotspot,” it is helpful to compare it to other farming activities:

Nitrogen Fertilizer: ~71% of total emissions.

Irrigation (Energy use): ~8% (the second-largest source).

Lime: ~6%.

Pesticides/Plant Protection: ~4.8%.

5. Implications for Mitigation: Because synthetic nitrogen is the primary hotspot, it also represents the greatest opportunity for decarbonization. The study concludes that reducing inorganic fertilizer use and substituting it with organic alternatives (such as animal manure or compost) is the most impactful strategy for lowering the carbon footprint of these farms. Systems that relied less on intensive fertilization, such as coffee intercropped with avocado, demonstrated significantly lower overall emissions

[1] N. V. Ky (2025). Assessment of Greenhouse Gas Emissions from the Intercropping Systems in Robusta Coffee Farms in Dak Lak, Vietnam. Graduate School of Science and Technology, University of Tsukuba

[2] IPCC (2021). Climate Change 2021 – The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press. https://doi.org/10.1017/9781009157896

[3] IPCC (2019). 2019 Refinement to the 2006 IPCC Guidelines for National Greenhouse Gas Inventories. https://www.ipcc-nggip.iges.or.jp/public/2019rf/vol4.html.

#WASI #SOFRI #consultation #Capacity #Cadmium #AuramineO #Durian

Nguyen Van Long, Pepper Research and Development Center, Western Highland Agriculture and Forestry Science Institute.

Black pepper is one of Vietnam’s key export crops, largely concentrated in the Central Highlands. In recent years, however, productivity and sustainability of black pepper production systems have been increasingly threatened by soil degradation and rising pressure from soilborne pests and diseases.

A study conducted by the Pepper Research and Development Center, Western Highlands Agriculture and Forestry Science Institute (WASI) in 2023, surveyed 150 intensive black pepper plantations across Dak Lak, Dak Nong, and Gia Lai provinces to assess soil acidification and nutrient balance under long-term intensive cultivation. The results identified three major constraints to sustainable production: (i) strong to very strong soil acidity (pH 3.55–6.40), (ii) low cation exchange capacity (CEC), and (iii) pronounced nutrient imbalances.

More than 80% of soil samples showed excessive phosphorus accumulation (>96 mg P/kg soil), while potassium deficiency was widespread, particularly in Dak Lak (57.6%) and Gia Lai (48%). Calcium (365-978 mg Ca/kg soil) and magnesium (108-161 mg Ca/kg soil) levels varied considerably across provinces, resulting in imbalanced nutrient ratios in many plantations. Correlation and principal component analyses highlighted soil pH and organic matter as the key factors regulating nutrient availability and retention. Spatially, Dak Lak exhibited the most severe soil acidification and CEC depletion; Dak Nong showed relatively stable soil fertility; and Gia Lai soils had higher nutrient levels but greater variability among farms.

These constraints not only reduce fertilizer-use efficiency but also weaken root systems and create favorable conditions for soilborne diseases such as Phytophthora, Fusarium, and plant-parasitic nematodes. The study recommends prioritizing correction of soil acidity, improving soil buffering capacity, and adopting balanced, soil-test–based nutrient management to restore soil health and ensure the long-term sustainability of black pepper production in the Central Highlands.

Author: Nguyễn Văn Long     Phone: 0935 493 127    Mail: vanlongpleiku@gmail.com

Download: https://smujo.id/aja/article/view/23725

PhD. Nguyen Van Long

Determining the harvest stage is one of important factors that directly affect the yield and quality of black pepper. The experiment investigated the effect of harvesting ripe levels of pepper fruits on quality in Gia Lai and Dak Lak provinces, including 5 treatments: CT1 (the number of ripe fruits/spike > 75%), CT2 (the number of ripe fruits/spike > 50%), CT3 (the number of ripe fruits/spike > 25%), CT4 (the number of ripe fruits/spike > 5%), CT5 (the number of ripe fruits/spike < 5%). The results showed that the levels of ripe fruits affect both the physical (percentage of firmness, ratio of fresh fruits to peppercorn and weight of 1,000 peppercorns) and chemical characteristics (piperine, volatile oil and ete) of peppercorns. The physical parameters increased gradually as ripeness levels increased and there was a statistically significant difference between the treatments (P < 0.05); however, the chemical compositions of peppercorns decreased. To achieve the highest chemical contents of peppercorn, harvesting should be done when the ripe fruits/spikes are less than 5%. On the other hand, harvesting should be done when ripe fruits/spike is over 75% to achieve the best physical parameters, fitness, and appearance of peppercorns. The study has provided scientific evidence related to changes in peppercorn’s physical and chemical properties caused by different ripeness levels, helping producers choose appropriate harvest stages to meet various product quality and yield requirements.

Contact author: Nguyen Van Long, Mail: vanlongpleiku@gmail.com

Article download address:

http://tapchikhoahoc.nnmt.net.vn/vjae/article/view/942

Abstract

Monoculture and intensive fertiliser use in the cultivation of Robusta coffee (Coffea canephora var. Robusta) and black pepper (Piper nigrum L.) have led to soil degradation and increased disease pressure in Vietnam’s Central Highlands. To identify key factors driving soilborne diseases and threatening sustainable production, a soil and root survey was conducted across three provinces: Gia Lai, Dak Lak, and Dak Nong. Soils were characterised by high clay content (51.2–62.0 %), moderate silt (35.5–46.0 %), and low sand (2.5–2.8 %), with a notably low cation exchange capacity (7.72–8.04 cmol_c kg⁻¹). The soils were strongly acidic, with average pH values of 4.51 in coffee farms and 5.45 in pepper farms. Despite sufficient levels of nitrogen (N), phosphorus (P), and potassium (K), soilborne pathogens were widespread. Fusarium spp. were detected in all samples, Phytophthora spp. in 64–76 % of black pepper farms, and plant-parasitic nematodes in 67–84 % of farms, with Meloidogyne spp. predominant. Fusarium density increased with soil acidity in coffee plantations. In coffee, nematode density was positively correlated with N input, while in black pepper, N was negatively correlated with Phytophthora. Organic matter and available K were negatively associated with Fusarium in coffee but positively with Phytophthora in black pepper. These findings underscore the need for integrated management of nutrients and pathogens to sustain perennial crop production in the region.

Pepper Research and Development Center, 322 Truong Chinh, Hoi Phu Gia Lai.

^*Email: vanlongpleiku@gmail.com ; ĐT: 0935 493 127

ABSTRACT

Pinto peanut (Arachis pintoi) is a versatile legume that helps protect soil, improve its physicochemical properties, and, significantly, fix nitrogen. The study aimed to identify the biomass, nutrient content, and the effects of Arachis pintoi mulch on soil fertility and the yield of Black pepper (Piper nigrum L. cv. Vinh Linh). The experimental design consisted of two blocks without replication across two locations on productive Black pepper plantations in Gia Lai and Dak Lak. The trial consisted of two treatments: A+ (Arachis pintoi planted in inter-rows of Black pepper and A- (the unplanted control). After two years, depending on intercropped areas, Arachis pintoi produced an average of 5.31 MT of fresh biomass/ha/year (equivalent to 1.48 tonnes of dry biomass/ha/year). Arachis pintoi contributed an average of 32.7 kg N + 4.2 kg P and 17.9 kg K/ha/year through this bio-mulching practice. Moreover, Arachis pintoi mulching significantly improved soil pH, organic carbon, nitrogen, phosphorus, and potassium concentration when compared to the control by 1.87 – 6.59%, 7.36 – 13.58%, 9.52 – 11.75%, 7.95 – 11.87%, and 3.57 – 4.96%, respectively. However, the study did not find differences in crop yield between treatment and control, regardless of location. Arachis pintoi should be recommended for sustainable Black pepper production in Vietnam. These findings provide evidence that cover cropping with Arachis pintoi could reduce overall nitrogen fertilizer applications, reduce soil erosion, maintain soil moisture, and contribute to the sustainable development of the pepper industry.

Keywords: Black pepper, Arachis pintoi, intercropping, and soil health improvement.

Sexual hybridation is primary method for black pepper breeding in order to select good varieties with higher productivity, yield, quality as well as resistance to disease and environmental risks. Research showed that white pepper seeds germinated after 13-27 days after incubation, most of seeds were germinated 15-23 days after incubation with 56,1-86,9% of seeds germinated. The three-month old seedlings of  H-DP6 and  H-L1 showed better growth with good plants accounted for 54,17 and 80,83%, respectively.

Sáng ngày 15 tháng 7 năm 2022, tại Viện Khoa học Kỹ thuật Nông Lâm nghiệp Tây Nguyên, Đơn vị chủ trì và nhóm nghiên cứu đã tổ chức Hội thảo tham vấn ý kiến chuyên gia về xây dựng mô hình OCOP dựa vào nội lực cộng đồng; Hội thảo là một trong những nội dung của Đề tài: “Nghiên cứu đề xuất xây dựng mô hình OCOP (One commune one product – Mỗi xã một sản phẩm) dựa vào nội lực cộng đồng tại tỉnh Đắk Lắk”.
Đại biểu tham dự Hội thảo gồm: TS. Phan Thanh Bình – Trưởng Phòng Khoa học và Hợp tác quốc tế – WASI chủ trì Hội thảo; đại diện Sở Khoa học và Công nghệ tỉnh Đắk Lắk – PGS. TS. Phạm Thế Trịnh; đại diện các nhà quản lý, các nhà khoa học và các chủ thể OCOP của tỉnh Đắk Lắk.
Mục đích của Hội thảo là tham vấn ý kiến chuyên gia để hoàn thiện các tài liệu hướng dẫn xây dựng OCOP dựa vào nội lực cộng đồng tại tỉnh Đắk Lắk.
Hội thảo đã được nghe nhóm nghiên cứu và chuyên gia trình bày các bài tham luận: Kết quả lựa chọn để xây dựng mô hình mẫu OCOP dựa vào nội lực cộng đồng; Giải pháp phát huy nội lực cộng đồng để xây dựng OCOP tại tỉnh Đắk Lắk; Một số vấn đề khó khăn khi xây dựng sản phẩm OCOP trong vùng đồng bào dân tộc thiểu số; Một số lưu ý trong xây dựng hồ sơ OCOP; Đánh giá những thành công, hạn chế và nguyên nhân của hạn chế trong phát triển sản phẩm OCOP tại địa bàn tỉnh Đắk Lắk; Một số giải pháp nâng cao hiệu quả, chất lượng sản phẩm OCOP; Nhận diện 5Ps trong triển khai kế hoạch xúc tiến thương mại và quảng bá sản phẩm OCOP tỉnh Đắk Lắk: Phân tích và giải pháp. Đây là các nội dung chính mà nhóm nghiên cứu đưa ra để xin ý kiến tham vấn của các chuyên gia, các nhà quản lý, các đơn vị hưởng lợi, các chủ thể OCOP nhằm xác định các vấn đề chính và định hướng các giải pháp phát triển OCOP trên địa bàn.
Hội thảo đã nhận được nhiều ý kiến thảo luận từ các đại biểu về các vấn đề liên quan đến xây dựng mô hình OCOP dựa vào nội lực cộng đồng, trong đó đặc biệt chú ý tới các ý kiến: cần xác định yếu tố nào là chính, yếu tố nào là phụ của nội lực để có giải pháp phát huy trong cộng đồng đạt hiệu quả cao; làm thế nào để tổ chức tốt sản xuất: đó là hỗ trợ hình thành tổ hợp tác và hợp tác xã, ứng dụng công nghệ số trong khâu sản xuất, chế biến, hỗ trợ lưu thông và tiêu thụ sản phẩm…; Công tác truyền thông cần được chú trọng, truyền thông phải dễ hiểu, phù hợp với người dân để người dân hiểu rõ hơn về OCOP, lợi ích thiết thực khi tham gia OCOP; Lựa chọn sản phẩm OCOP phải hợp thị hiếu và có sức cạnh tranh trên thị trường; Thúc đẩy và phát huy cao độ năng lực của cộng đồng để xây dựng tốt các mô hình OCOP tại tỉnh Đắk Lắk.
Phát biểu kết luận Hội thảo, TS. Phan Thanh Bình ghi nhận tất cả các ý kiến và cảm ơn các đại biểu đã đóng góp ý kiến hết sức thẳng thắn và quý báu. Đồng thời yêu cầu Ban chủ nhiệm Đề tài tiếp thu, rà soát và hoàn thiện tài liệu để góp phần hoàn thiện các sản phẩm của đề tài, đáp ứng các yêu cầu của Sở Khoa học và Công nghệ và của Tỉnh Đắk Lắk.

Tran Van Phuc, Nguyen Xuan Hoa, Nguyen Thi Van

Western Highlands Agriculture and Forestry Science Institute

Booth 7 avocado has high yield, good fruit quality, good appearance, and late harvesting season, which is suitable for Central Highlands. To contribute to the development and improvement of avocado production, the research experiments to complete the intensive process of Booth 7 avocado were carried out from 2018 to 2019 in Dak Lak and Lam Dong provinces. The results showed that the appropriate fertilizer dose recommended for adult phase is 1.0 N + 0.3 P₂O₅ + 0.9 K₂O + 0.1 CaO kg/tree at average yield from 50 to 60 kg/tree. Watering several times with a cycle of 10 days (12 times a year), an amount of 500 – 600 liters/tree at the flowering period and exponential fruit growth is necessary, it gives the highest yield. The treatment with Matalaxyl (Mataxyl 500WG) + Trichoderma spp. (Vi – DK) had the highest effect on the disease incidence of Phytophthora root rot disease, followed by Phosphorous acid (Agri-Fos 400SL) + Trichoderma spp. (TricôĐHCT-Phytoph).