https://ir.kdu.ac.lk/handle/345/6285 2026-04-06T12:55:06Z 2026-04-06T12:55:06Z Swarnathilake, DSGGC Dalpitiya, DMAU Herath, HMIK Gimhani, DR https://ir.kdu.ac.lk/handle/345/6507 2023-07-06T07:33:10Z 2022-09-01T00:00:00Z

Evaluation of growth, yield, and nitrogen losses from leafy red onion cultivation with different fertilizer practices in Kalpitiya peninsula Swarnathilake, DSGGC; Dalpitiya, DMAU; Herath, HMIK; Gimhani, DR Intensive agriculture practices together with increased fertilizer use have a greater impact on groundwater quality in Kalpitiya.Water demand in Kalpitiya is 70% fulfilled by groundwater extractions. The demand is ever increasing due to increase of population and agricultural practices. The permeable nature of sandy Regosols causes heavy leaching of nutrients and contamination of shallow groundwater. The aim of this study was to evaluate the effects of different fertilizer practices on growth, yield and nutrient leaching in leafy red onion grown in Kalpitiya. The Red onion is the major crop grown on a large scale. The treatments tested were T1-Farmer Used Rate of fertilizer and T2-Department of Agriculture (DOA) recommendation. The experiment was arranged in Completely Randomized Block Design with three replicates in six plots (7.2m2). The red onion of Jaffna Local was established in a research field where lysimeters were previously installed. The leachate was collected weekly from lysimeters and analysed for leached nitrogen. Growth of plants and yield were recorded. A significant difference in leached nitrogen was observed between treatments. Furthermore, it was observed that there was a statistically significant difference between the final yield of T1 and T2 treatments. The total nitrogen leaching percentage of T2(67.88%) was lower than T1(78.86%) even though the crop yield of T2 (5069.25 kg/ac) was lower than T1(7556.95 kg/ac). The average concentration of nitrate in the leachate of T1 was 73 mg/l while that of T2 was 72 mg/l. The safe limit of nitrate in groundwater is 50 mg/l. Recommended amounts of fertilizer should be applied in balanced proportion and at appropriate times with soil amendments may help to absorb nutrients efficiently. Therefore, study concludes that, both practices showed leached nitrate concentrations above safe limits recommended by WHO which urges the need for change in nitrogen fertilizer management for red onion on sandy Regosols.

2022-09-01T00:00:00Z Hansika, EBT Upeksha, RGC Weerawardane, T https://ir.kdu.ac.lk/handle/345/6506 2023-07-06T07:29:32Z 2022-09-01T00:00:00Z

Secure Data Transformation in Cloud Using Hybrid Cryptography Hansika, EBT; Upeksha, RGC; Weerawardane, T The cloud is a very well-known and accepted data storage that provides many benefits to users with a pay-as-you-go pricing model, even providing storage solutions for massive amounts of data. Many users nowadays use different cloud services, mainly because the data can be accessed from anywhere via the internet. The cloud servers are located all over the world storing massive amounts of data. When a user uploads or downloads from the cloud server, the data is exposed to the internet. This can lead to security issues such as unauthorized disclosure of data and the privacy of users if the data is not properly protected. Many cryptographic algorithms are used to secure data transformation in the cloud. The proposed system is designed to offer a method for properly securing data when transferring them to the cloud, utilizing various cryptographic techniques, and integrating them most innovatively and effectively considering the security, data integrity, speed, and data confidentiality. The data is encrypted using a combination of three algorithms namely AES, ECC, and RSA by increasing the security of the data. The keys generated by the ECC and RSA are combined using an Exclusive OR gate. The AES key is uploaded into the key management server after being encrypted by the newly generated key. The data encrypted by the AES key are uploaded into the cloud storage. The proposed system is intended to distinguish the features and functionalities to overcome the drawbacks of the current systems.

2022-09-01T00:00:00Z Abeygunawardena, TS Chamara, N Amadoru, IJ https://ir.kdu.ac.lk/handle/345/6505 2023-07-06T07:24:56Z 2022-09-01T00:00:00Z

Use of sensor based automated irrigation for the mitigation of groundwater depletion and pollution issues in Kalpitiya, Sri Lanka Abeygunawardena, TS; Chamara, N; Amadoru, IJ Kalpitiya, is an important agroecological region in Sri Lanka, which has greatly strengthened the country’s economy and food security. However, intensive farming practices in Kalpitiya have triggered its ground water depletion and pollution isuses. The objective of this study was to check the feasibility of a new sensor-based irrigation system against the prevailing groundwater depletion and pollution issues in Kalpitiya. The new system was used to automate a sprinkler kit by monitoring underground moisture contents via its high-frequency soil water content sensors placed at 15, 45 and 90 cm depths. During the study, irrigation uniformity and adequacy of the automated sprinkler kit (T1) were compared over those of the sprinklers operated with common farmers’experience based (T2) and timer controlled (T3) irrigations. T2 and T3 were also provided with the soil moisture detection facility as same as in T1. According to the results, the irrigation uniformities of T1, T2 and T3 were within an acceptable range (83- 88%), but only T1 had 60% irrigation adequacy within 30cm depth. Further, soil water telemetric graphs and the adequacy values also proved that deep percolation was considerably higher in T2 and T3 over T1. The study confirmed that new sensor-based irrigation control was capable in saving irrigaton water and minimizing groundwater leaching through its real time soil moisture sensing mechanism. Thus, the new technique had the potential to used against the ground water depletion and pollution issues in Kalpitiya.

2022-09-01T00:00:00Z Samarawickrama, KGR Wijayapala, UGS Fernando, CAN https://ir.kdu.ac.lk/handle/345/6504 2023-07-06T07:20:25Z 2022-09-01T00:00:00Z

Green Synthesis of Iron Nanoparticles from Long coriander (Eryngium foetidum) Leaves Aqueous Extract Samarawickrama, KGR; Wijayapala, UGS; Fernando, CAN Green synthesis method is becoming more popular as an economical, energy-efficient, low cost and environment-friendly way of synthesis of iron nanoparticles (FeNPs). In this study, the aqueous extract of Long coriander (Eryngium foetidum) leaves was used as reducing and stabilizing agents in the synthesis of FeNPs. The aqueous extract of Long coriander (Eryngium foetidum) leaves can reduce from Fe3+ into iron nanoparticle (Fe0) at room temperature. The green synthesized iron nanoparticles were characterized by Scanning Electron Microscope (SEM) analysis, Energy Dispersive X-Ray (EDX) analysis, X-ray diffraction (XRD) analysis, Fourier transforms infrared (FTIR) spectroscopy analysis and UV-Visible (UV-Vis) spectroscopy analysis. The particles were identified as being on the nanoscale by SEM images and their surface morphology was revealed to be a spherical shape with a particle size range between 30-50 nm. The elemental composition of synthesized iron nanoparticles was detected by EDX spectroscopy analysis, which also revealed that the nanoparticles are primarily present in metal form. The XRD spectrum observed the crystal structure of the synthesized FeNPs and which have crystalline in nature with a size of around 43.30 nm. The FTIR spectrum exhibited different characteristic bands, which indicated the different functional groups of the active components in synthesized FeNPs. The UV-Visible observed the absorption peaks at the 250-295 nm region due to the excitation of surface plasmon vibrations of the FeNPs and the maximum peak was shown at 272 nm. The green synthesis method from synthesized FeNPs can be applied for a wide range of industrial applications.

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