http://repo.lib.jfn.ac.lk/ujrr/handle/123456789/74 2026-09-22T06:38:31Z http://repo.lib.jfn.ac.lk/ujrr/handle/123456789/13055 Title: Enhancing Water Security Through Automated Drip Irrigation: Impacts on Soil Moisture Dynamics and Brinjal Yield in Semi-arid Systems Authors: Herath, M.N.; Niranjan, M.; Pakeerathan, K.; Sinnathurai, J.A.; Kannan, N. Abstract: Improving irrigation efficiency is essential for sustaining vegetable production in water-limited environments, yet field-scale evaluations of practical time-based automated drip irrigation systems remain limited. This study compared an Automated Drip Irrigation Treatment (ADIT) employing scheduled time-based irrigation with a Manually Operated Drip Irrigation Treatment (MDIT) under polythene mulch for brinjal (Solanum melongena L.) cultivation in sandy loam soil during the 2025 Yala season in Sri Lanka. Soil moisture dynamics, irrigation uniformity, root distribution, wetting patterns, crop water requirement, yield, and irrigation water-use efficiency (IWUE) were evaluated using field measurements together with CropWat and HYDRUS-1D simulations. ADIT achieved consistently higher irrigation performance, with Christiansen’s coefficient of uniformity (CU) of 91–93%, emission uniformity (EU) of 90–92%, and distribution uniformity (DU) of 88%, compared with 75–80%, 78–82%, and 72%, respectively, under MDIT. Improved water distribution resulted in more stable root-zone soil moisture conditions, while HYDRUS-1D simulations predicted substantially lower deep percolation losses under ADIT than MDIT during crop development. Field observations also showed greater lateral root spread (40.7 cm vs 33.0 cm), higher irrigation water-use efficiency (4.91 vs 3.37 kg m-3), and greater marketable yield (22.3 vs 16.7 t ha-1; 2.35 vs 1.62 kg plant-1) under ADIT. Because the evaluated irrigation configurations differed in hydraulic characteristics as well as irrigation control strategy, and the study was conducted as a single-season field-scale pilot without replicated treatment plots, the findings should be interpreted as comparative evidence of system-level performance rather than effects attributable solely to automation. Nevertheless, the evaluated ADIT configuration demonstrated considerable potential for improving irrigation performance and water productivity under sandy loam, semi-arid conditions, warranting validation through replicated experiments using hydraulically identical irrigation systems. 2026-01-01T00:00:00Z http://repo.lib.jfn.ac.lk/ujrr/handle/123456789/12425 Title: Incorporation of Paddy Husk Biochar and the Effectiveness of Colocasia esculenta Usage in Vertical Flow Constructed Wetlands for Treatment of Synthetic Wastewater Having “Rhodamine B” Authors: Kannan, N.; Sirimanna, R.G.H.L. Abstract: Incorporation of paddy husk biochar (PHBC 350) and Colocasia esculenta (C. esculenta) usage in vertical flow constructed wetlands (VFCWs) for treatment of synthetic wastewater mixed with rhodamine B (RhB) was the focus. To increase the removal efficiency of VFCW, pebbles (0.0125 m 3 ), sand (0.005 m 3 ), and PHBC 350 (0.0075 m 3 ) were used. Setups of VFCWs, S (sand) and SB (sand + biochar [30% v/v]), were established. DO, pH, TS, TDS, TSS, EC, color, turbidity, dye concentration, and RhB removal percentage were evaluated. The measured values of DO, EC, pH, TS, TDS, and TSS in SB were 6.03 mg/L, 1.72 mS/cm, 6.14, 1080 ppm, 860 ppm, and 220 ppm, respectively, in 10 days. Moreover, SB gave a statistical level of RhB removal of 81.5%. All in all, incorporation of biochar into VFCWs created new knowledge to advance the removal performance for wastewater mixed with organic pollutants by understanding its mechanistic dynamics. 2026-01-01T00:00:00Z http://repo.lib.jfn.ac.lk/ujrr/handle/123456789/12424 Title: Biogenic carbon matrix with dual-mode adsorption capability: synthesis, characterization and mechanistic insights Authors: Kannan, N,; Srinanthakumar, N.; Goonetilleke, A.; McGree, J.; Bandala, E.R. Abstract: The transformation of biowaste into high-performance functional materials presents a promising strategy for sustainable environmental technologies. In this study, a novel biogenic carbon-based catalytic matrix (CBCM) was synthesized from prawn shell waste, integrating chitin-derived carbon and in-situ formed calcite to yield a hybrid material with distinctive structural and surface characteristics. Comprehensive characterization using X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR) revealed a composite architecture featuring both organic (Chitin) and inorganic (Calcite) crystalline domains, along with abundant surface oxygenated functional groups (O–H, C=O, CO–NH, and C–O). These structural attributes underpin the CBCM's dual-mode adsorption capability, enabling simultaneous and efficient uptake of both cationic (Malachite green) and anionic (Congo red) dyes. Kinetic and isotherm analyses highlighted the dominant roles of hydrogen bonding and π-π interactions, directly linked to the material's functional groups and porous surface morphology. Response surface modeling confirmed strong agreement between predicted and experimental adsorption capacities (R 2 = 0.978), underscoring the reliability of the structure-function correlation. This work demonstrates how rational design and valorization of marine biowaste can yield multifunctional materials, with the CBCM serving as a proof-of-concept platform for pollutant capture and broader environmental applications. 2026-01-01T00:00:00Z http://repo.lib.jfn.ac.lk/ujrr/handle/123456789/12423 Title: Optimizing spray volumes of different spraying devices under controlled conditions for Abelmoschus esculentus (Okra) cultivation: A scientific exploration towards automation in spraying Authors: Kannan, N.; Loveciya, S.; Mayuresh, N. Abstract: Spraying is one of the important techniques to control pest infestation in vegetable fields. Improper pesticide application leads to chemical wastage and ineffective pest control, causing environmental pollution and ultimately reducing crop yield. To overcome these issues and to suggest suitable spraying techniques for particular growth stages of Abelmoschus esculentus (okra), a comprehensive field experiment was planned. Four different spraying techniques using hand-operated knapsack sprayers and power-operated knapsack sprayers: hand-operated knapsack low-volume (KL), hand-operated knapsack high-volume (KH), power-operated knapsack low-volume (PL), and power-operated knapsack high- volume (PH), were used with the incorporation of sensor technology to identify the pest and suitable pesticides. Major differences in droplet sizes among the treatments KL, KH, PL, and PH were 2.6±0.03 μm, 2.4±0.08 μm, 2.3±0.17 μm, and 2.1±0.05 μm, respectively. The results showed that treatment KL outperformed the other treatments at the seedling stage, and treatment KH was the optimal choice for the vegetative and fruit-bearing stages of okra for plant infestation and 90% wetting. The highest pest infestation was observed during the vegetative stage. Yield performance was induced by treatment KH, with the longest average pod length at 23.2±0.37 cm. Overall, with the advantages of plant interception, environmental loss, plant height, and pest infestation level, the KH more effectively supported all stages of okra development. The findings of this study emphasized a suitable spraying technique for each growth stage of okra with minimum environmental loss by incorporating sensors. The use of technology in basic agricultural activities is highly expected; thus, these findings will be useful for agricultural experts, farmers, and researchers in promoting eco-friendly and sustainable agriculture by minimizing chemical usage through precision pest management. 2026-01-01T00:00:00Z