Conference Proceeding

Effectiveness of WhatsApp-Based Weather Information Dissemination - A Case Study Based on Two Cascade Systems under CRIWMP in the Dry Zone, Sri Lanka

2026-01-01T00:00:00Z

Effectiveness of WhatsApp-Based Weather Information Dissemination - A Case Study Based on Two Cascade Systems under CRIWMP in the Dry Zone, Sri Lanka Wickramasinghe, W.R.M.R.L.K.; Wijerathne, M.A.Y.K.; Jayaweera, A.; Weerahewa, J. Changing climatic conditions are serious challenges to agricultural productivity, especially in the Dry Zone in Sri Lanka. In such contexts, timely, accurate weather information is critical for enabling climate-resilient agricultural decisions. The Climate Resilient Integrated Water Management Project (CRIWMP) has introduced WhatsApp-based weather information dissemination to support farmers. Despite the availability of WhatsApp-based weather information, its effectiveness in supporting farmers’ decisions remains unclear. This study examines the effectiveness of this approach, considering two cascades that benefited from CRIWMP; the Thuduwakkaikulam cascade and the Sivalakulama Cascade. Rogers's Diffusion of Innovations theory, which highlights factors influencing adoption, including relative advantage, compatibility, complexity, trialability, and observability, was used as the framework guiding the study. A qualitative case study design was adopted, employing purposive sampling to select farmers in WhatsApp groups. Data were collected through Focus Group Discussions conducted in Sinhala and translated into English. Thematic analysis generated five key themes: Establishment and Institutional Support, Information Type, Comprehension, Accuracy and Information Use, and Limitations and Unmet Needs. Findings indicate that WhatsApp groups provide localized, timely, and actionable weather information, enhancing decisions related to irrigation, fertilizer and pesticide application, harvesting, and tank management. Challenges included comprehension difficulties, message overload, limited digital literacy, and insufficient awareness of group existence. Addressing language barriers, simplifying messages, and raising awareness of group availability can improve adoption and impact. These findings show the potential of WhatsApp as an information source to strengthen climate adaptation strategies for farmers in Sri Lanka’s Dry Zone.

Spatial Assessment of Soil Erosion in a Gently Sloping Coconut Plantation at Dambadeniya (IL1), Sri Lanka

2026-01-01T00:00:00Z

Spatial Assessment of Soil Erosion in a Gently Sloping Coconut Plantation at Dambadeniya (IL1), Sri Lanka Dilshani, D.M.C.N.; Jayawardana, H.M.A.S.; Subashini, J.K.W.N. Soil erosion is a major land degradation process affecting agricultural sustainability, soil fertility, and long-term productivity. In low-country agricultural systems, erosion risk is often assumed to be minimal due to gentle slope conditions; however, variations in land cover and management can still generate spatial differences in soil loss. This study applied the Revised Universal Soil Loss Equation (RUSLE) model integrated with Geographic Information System (GIS) techniques to assess spatial soil erosion patterns in a coconut plantation managed by the National Livestock Development Board (NLDB) in Dambadeniya, Sri Lanka, within the Low Country Intermediate Zone (IL1). Rainfall data, soil properties, Digital Soil Map of the World, Digital Elevation Model (DEM), and satellite imagery were used to derive rainfall erosivity (R), soil erodibility (K), slope length and steepness (LS), vegetation cover factor (C), and support practice factor (P) .The P factor was assigned based on existing land-use conditions and published RUSLE literature, considering the absence of engineered soil conservation measures. ArcGIS was used to integrate all factors and generate an annual soil loss map. The study area covers 619 acres, including 495 acres (79.97%) cultivated coconut land and 124 acres (20.03%) uncultivated land. Estimated annual soil loss ranged from 0 to 3.58 t ha⁻¹ yr⁻¹, which falls within the low erosion category (<5 t ha⁻¹ yr⁻¹). Although overall erosion is low, spatial variability was observed across the landscape. Higher soil loss was mainly associated with reduced vegetation cover and weaker land management practices, while well-vegetated areas showed minimal erosion. The study demonstrates that in the study area, even gently sloping coconut landscapes exhibit spatially variable erosion controlled mainly by land cover. GIS-based RUSLE modelling effectively identifies erosion variability and supports targeted land management planning.

Green Synthesis of Iron Nanoparticles using Made Tea and Refused Tea for Dye Removal in Wastewater

2026-01-01T00:00:00Z

Green Synthesis of Iron Nanoparticles using Made Tea and Refused Tea for Dye Removal in Wastewater Athapaththu, M.A.A.P.M.; Lochana, E.A.L.; Ellepola, V.P.; Perera, G.A.A.R. Iron nanoparticles are emerging as cost-effective and eco-friendly materials for wastewater treatment. This study developed a sustainable method for synthesizing iron-based nanoparticles using aqueous extracts of made tea and refused tea from black and green tea varieties. Refused tea, which accounts for 4–6% of Sri Lanka’s total tea production, is recognized as a waste material that can be used for environmental remediation. This study allowed tea extracts (10% w/v, pH ~5.5) to react with 0.10 M FeCl₃ under mechanical stirring at room temperature for 15 minutes, for the synthesis of nanoparticles. FTIR, UV-Visible Spectroscopy, XRD, and SEM were employed for characterization. FTIR confirmed involvement of polyphenolic functional groups in iron reduction and stabilization, while Fe–O vibrations verified iron oxide formation. Nanoparticle synthesis was confirmed by UV-Vis spectra, which showed strong absorption around 390 nm. XRD indicated predominantly amorphous structures with weak reflections corresponding to α-Fe. SEM analysis revealed irregular quasispherical particles (30–80 nm) with agglomeration due to magnetic interactions. Synthesis yield varied among tea types, with green tea samples showing higher yields than black tea. The nanoparticles were evaluated for methyl orange dye removal under optimized conditions (50 mg/L, pH 6.5, 120 min). Black made tea nanoparticles achieved the highest removal efficiency (80.5%), followed by green made tea, green refused tea, and black refused tea nanoparticles. Increased nanoparticle dosage further improved removal efficiency. The findings demonstrate the potential of tea-derived iron nanoparticles as sustainable and efficient adsorbents for dye-contaminated wastewater treatment while promoting tea waste valorization.

Carbon Sequestration Potential of Cashew Plantations under Varying Tree Densities in a Dry Zone Agroforestry System

2026-01-01T00:00:00Z

Carbon Sequestration Potential of Cashew Plantations under Varying Tree Densities in a Dry Zone Agroforestry System Jayawardana, H.M.A.S.; Wijetunge, P.M.A.P.K.; Attanayaka, D.P.S.T.G.; Abeysinghe, D.C. Cashew (Anacardium occidentale L.) is an important perennial crop with significant potential for carbon sequestration in tropical dry zone agroforestry systems. However, information on the influence of planting density on biomass carbon and soil organic carbon (SOC) accumulation under long-term plantation conditions remains limited. This study evaluated the effect of five planting densities on above-ground biomass carbon (AGB), below-ground biomass carbon (BGB), SOC, and total ecosystem carbon (TEC) in a field experiment established in 2012 at the Puttalam Plantation of the Sri Lanka Cashew Corporation. The experiment was arranged in a Randomized Complete Block Design (RCBD) with three replicates using cashew variety WUCC 19. Five spacings were evaluated: 7.62 m × 7.62 m, 7.0 m × 7.0 m, 6.0 m × 6.0 m, 5.4 m × 5.4 m, and 4.8 m × 3.9 m. AGB was estimated using a DBH-based allometric equation, while BGB was derived using the IPCC (2019) Tier 2 root-to-shoot ratio model. TEC was calculated as the sum of biomass carbon and SOC. Data were analyzed using ANOVA followed by Tukey’s HSD test at p < 0.05. Results showed a significant effect of planting density on carbon sequestration. TEC increased progressively with higher planting density, from 51.0 Mg C ha⁻¹ at 7.62 m × 7.62 m spacing to 67.0 Mg C ha⁻¹ at 4.8 m × 3.9 m spacing, while intermediate spacings recorded 54.5, 58.5, and 62.5 Mg C ha⁻¹, respectively. Similar increasing trends were observed for AGB, BGB, and SOC. The findings demonstrate that closer planting densities significantly enhance carbon sequestration potential in dry zone cashew agroforestry systems and provide a scientific basis for climate-smart plantation management.