iPURSE 2015

Permanent URI for this collectionhttps://ir.lib.pdn.ac.lk/handle/20.500.14444/41

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Identifying impact of work life conflict on job satisfaction
(University of Peradeniya, Sri Lanka, 2015-11-06) Lankeshwara, P.
Ceylon Electricity Board (CEB) is a body corporate for electricity undertaking in Sri Lanka. It conducts its massive duties to the Sri Lankan public though Generation, Transmission, Distribution and other services. One of the major problems that the results of pilot survey has revealed is that, among the CEB workforce many of non-executive staff in CEB-Sabaragamuwa are facing problem of work life conflict. At present the conflict between work and family has become a crisis for organizations. With the increase in dual family parents, more job demand and long working hours made it almost impossible to create a balance between work and family. This situation automatically reduces job satisfaction of the employees and then affects the productivity and profitability of the organization. The overall objective of this research was to analyze the factors related to work life conflict and its impact on job satisfaction at the CEB-Sabaragamuwa Provincial Office. The data were collected by distributing a questionnaire and the sample has comprised 120 non-executive employees. Pearson correlation test and Regression analysis were utilized as data analysis techniques. The results revealed that work life conflict impacts on reducing the job satisfaction. Further, family to work conflict could be identified as the most critical predictor. Ultimately work life conflict of non-executive staff employees of CEB negatively impact on their job satisfaction. The relationship between work life conflict and job satisfaction is inversely related to each other.
Mobile phone as a mode of information provident to up country vegetable farmers in Sri Lanka
(University of Peradeniya, Sri Lanka, 2015-11-06) Perera, D.G.D.; Mahaliyanaarachchi, R.P.; Sivashankar, P.; Hettiarachchi, I.C.
This study explores the status of mobile usage as a mode of providing information to the agriculture community in the upcountry region in Sri Lanka. The objectives of the study were to find out the awareness level, usage, attitudes of upcountry vegetable farmers about the mobile phone based information systems and services, to find out the factors affecting on mobile usage by farmers and their willingness to pay for mobile phone based information systems and services. Primary data were collected using an interviewer administrated questionnaire (n=120). Findings reveal that the access to mobile phones was considerably higher among the study group, while income had an effect on using a mobile phone. Most of the farmers use mobile phones to communicate with family, friends and relatives. Only few farmers use them effectively to obtain agriculture related information. Awareness and usage of mobile phone based information systems and services are at a lower level. Attitudinal barriers and less awareness are the major reasons for this situation. There is a positive relationship between the usage of mobile phone based information systems and services and farmers attitudes on its impact on knowledge and income. Farmers who are using the mobile phone based information systems and services highlighted that the services are very much helpful for agriculture development.
Unemployment, official economy and dimensions of the shadow economy: an empirical analysis for Sri Lanka using sem approach
(University of Peradeniya, Sri Lanka, 2015-11-06) Samaranayake, D.I.J.; Dayarathna-Banda, O.G.
Economists and policy makers confront a series of issues when accounting all unobserved market fractions in a challenging market economy. These challenges have become worse within complex market structures in developing economies. One of these challenges is the expansion of unobserved and unofficial economic activities which is generally known as the ‘Shadow Economy’. This study basically attempts to estimate the Sri Lankan shadow economic activities as a percentage of official estimates, while revolving the wheel of non-clarified zones and market functions through overstepping the traditional official estimates. Objectives of the study are addressed through three equally important portions. Initial portion intend to choose and develop suitable, fitted MIMIC (Multiple Indicator Multiple Cause) models while using the structural relationship between the unemployment rate and shadow economy to estimate the size of the shadow economy in Sri Lanka. Then the following portion is to estimate shadow economy for each fitted model through benchmark calculations. Finally, to examine if estimated models and their calculations are accepted by re-examination of Okun’s law and to contrast estimated results in growth terms to the growth of official estimates (GDP) of the economy. Therefore, the methodology involves the estimation of structural equation models, which analyses a set of causes of the shadow economy while simultaneously taking in to account its influence upon a series of indicators. This study introduces three MIMIC models through the analysis that are MIMIC 5-1-2a, MIMIC 4-1-2b and MIMIC 3-1-3a. Then the benchmark calculations for each model derives a series of average values for the Sri Lankan shadow economy from 1990-2012. Calculations for MIMIC 5-1-2a vary between 91% and 32% from 1990 to 2012 with a decreasing trend. On the other hand, calculations for MIMIC 4-1-2b and MIMIC 3-1-3a demonstrate the average size of shadow economy between 14% and 52% with an increasing trend. Further discussions, therefore, reveal the fact that, the effect from tax on goods and services to the government revenue and the effect from public employment tend to undermine the increasing pattern of shadow economy in Sri Lanka. Since unemployment rate and private employment plays a major role in economy, shadow economy tends to increase. Eradicating the workplace enforcement crisis and underemployment issues may hinder the increasing pattern. Ultimately, the results from re-examination of Okun’s law give a hint that the growth of shadow economy and official economy are not interdependent and have a parallel growth with shifting stages in market functions.
The impact of corporate social responsibility (csr) on brand equity : a study with special reference to Sri Lanka telecom plc
(University of Peradeniya, Sri Lanka, 2015-11-06) Shibly, F.H.A.; Hilal, M.I.M.
Today, Investment on Corporate Social Responsibility (CSR) has become the common business practices in the world. CSR is receiving increasing attention, especially in recent decades. At the same time, various stakeholders, especially, shareholders are more frustrated with the investment on the Corporate Social Responsibilities which will affect indirectly to the Brand Equity of the organization. Further there are various pros and cons about CSR, which impact the brand equity of the organization. Sri Lanka Telecom PLC (SLT) is the blue chip company in which CSR has become the most common practices in the SLT business agenda. The SLT has invested on CSR aspects. It is found that there are only few researches have been carried out in Sri Lankan context to find out the impact of CSR on brand equity and there is a need to measure it for organization’s effective CSR decision makings. The major objective of this research is to explore and investigate how a company’s corporate social responsibility activities are influencing its brand equity. By reviewing the existing literature on CSR and brand equity of the SLT, this study developed a better understanding of gaps that exist. In order to achieve the objective, the research draws from well-established theoretical models; the Caroll model which presented four variables on CSR. This model has been used by many researchers to measure the CSR activities of firms. According to this model, there are four perspectives such as economic, social, legal and ethical perspectives and the Aakers’ model has been used to measure the brand equity. The research adopted quantitative method to explore impact of CSR on brand equity of the SLT and data were collected by means of online survey tool and printed questionnaires. A survey was conducted among 100 customers who use the SLT services. Regression and correlation analysis, including partial correlation, linear, binary logistic regression, was used to obtain the results that helped identify the impact of CSR on brand equity of the SLT. The results of the study showed that corporate social responsibility is positively impacted on brand awareness, brand loyalty, perceived quality and brand association of the SLT PLC. Thus there is a positive impact of CSR on brand equity and if the SLT invests more on CSR activities, the value of their brand equity will be increased.
Forecasting international tourism income of Sri lanka : trend analysis
(University of Peradeniya, Sri Lanka, 2015-11-06) Konarasinghe, K.M.U.B.
Growth of the tourism industry in Sri Lanka shows the historical development mainly in two ways. That is the growth of tourist arrivals and income. Tourism impacts on the economy of Sri Lanka, which rely heavily on foreign exchange earnings. This has been a general interest of the government. Therefore, the government needs reliable forecasting to cope with uncertain situations and developing sound strategies to maintain the growth of tourism industry. This study was focused on identifying an appropriate trend model for forecasting international tourism income of Sri Lanka. Monthly income data from 2009 to 2013 were obtained from statistical reports of 2012 and 2013 of Sri Lanka Tourism Development Authority (SLTDA). The study concerns the period of post-war, which is after the year 2009. Model fitting was done by utilizing data from January 2009 to April 2012 and data from May 2012 to May 2013 were utilized for model verification. Four trend models were tested with log transformation including one linear and three nonlinear models. Residual plots and Anderson-Darling tests for residuals were used as the model validation criterion. Forecasting ability of the models was assessed by considering Mean Absolute Percentage Error (MAPE), Mean Square Error (MSE) and Mean Absolute Deviation (MAD). Box and whisker plot showed no outliers in the data set. Results revealed that Quadratic Trend Model has least MAPE’s in model fitting and verification: 0.90% and 1.12 %, respectively. MAD and MSE also confirmed the smallest deviation compared with other trend models. Residual plots and Anderson-Darling test confirmed the normality of residuals. Also, residuals Vs fits confirmed the independence of residuals. It was concluded that the Quadratic Trend Model with log transformation is suitable for forecasting international tourism income in Sri Lanka. Monthly income for the period from May 2012 to November 2013 were forecasted by the model and found them close to the actual income. It is recommended to try other time series techniques, namely, decomposition techniques, Auto Regressive Integrated Moving Average (ARIMA) models etc., to capture the seasonal behavior of the series.
Decolourization of crystal violet synthetic dye from aqueous solution by woody biochar
(University of Peradeniya, Sri Lanka, 2015-11-06) Wathukarage, A.; Iqbal, M.C.M.; Priyantha, H.M.D.N.; Vithanage, M.
Colour removal from textile effluents prior to their disposal is an emerging concern due to its adverse effects on the environment and public health. Biochar can be used effectively as a biosorbent for removal of dye contaminants. This study investigated the adsorption of a basic dye, Crystal Violet (CV), from aqueous solutions on to biochar derived from Gliricidia sepium pyrolysed at 700 °C (GBC700). Pyrolysis was done under a heating rate of 7 °C min⁻ ¹. The adsorption process was investigated through batch experiments by varying pH, adsorbent dose, initial dye concentration, and contact time. The sorbent dosage, initial dye concentration and contact time were set as 0.5 - 6.0 g L⁻¹, 5 - 200 mg L⁻¹ and 5 min - 24 hr, respectively. The effect of pH was determined through edge experiments at pH 3 to 9. The equilibrium data was analyzed using the Langmuir, Freundlich and Hill isotherm models. Pseudo first order, Pseudo second order and Elovich kinetic models were used to investigate the kinetic data. Results indicated that the optimal adsorbent dose was obtained at 2 g L⁻¹ and the optimum contact time was 12 hr. The adsorbed amount was increased from 5.5 mg g⁻¹ at pH 3 to 8.0 mg g⁻¹ at pH 9 while the equilibrium was reached at pH 7. Since higher pH conditions lead to increasing the negative charge density of GBC700 and the electrostatic attraction to the dye cations can be enhanced. Crystal Violet removal efficiency was 99% at 20 mg L⁻¹. According to the Langmuir model, maximum adsorption capacity was observed at 30.4 mg g⁻¹ at 30 °C. The experimental data fitted well with the Freundlich isotherm model (r² = 0.9788) and Pseudo second order kinetic model (r² = 0.9703) which suggests the importance of multilayer adsorption to heterogeneous sites in biochars. The adsorption process is highly pH dependent. Crystal Violet molecule may interact with the GBC700 through the mechanism of 𝝅-𝝅 electron donor-acceptor interactions between the π-electron rich graphene surface of biochar and 𝝅-electron deficient CV dye molecule. The use of Gliricidia biochar pyrolysed at 700 °C could be a sustainable solution to remove CV in aqueous media while compromising the waste problem by using Gliricidia byproduct.
Climate change adaptation practices in crop cultivation : case study in Anuradhapura district
(University of Peradeniya, Sri Lanka, 2015-11-06) Ranasingha, R.M.C.K.; Nanthakumaran, A.
Climate change, mainly the variation in rainfall in the recent past years, causes frequent floods and drought in many districts in the country. The variation in rainfall and frequent floods and droughts affect the crop cultivation, and thereby challenging the food security of the country. Further, it affects the livelihood of the farming community in the tank based agriculture systems which includes the major and the minor irrigation tanks. Many minor irrigation tanks receive water from rainfall, store and supply for agriculture during non-rainy season. Very often the water stored in the minor irrigation tanks is not sufficient to fulfill the water requirement for agricultural purpose, because of the limited tank storage. The objective of this study was to identify the adaptation measures practiced by the farmers to overcome the effects of climate change due to rainfall variation under minor irrigation tanks. Since Anuradhapura district lies in the dry zone of Sri Lanka and many small and marginal farmers involved in crop cultivation, it was selected for this study. Stratified random sampling was done to select 150 farm households from 15 minor irrigation tanks in Anuradhapura district. Primary data from the farm households using structured questionnaire and the rainfall data for the past 31 years from the year 1984 as secondary data from the Meteorology Department were collected for analysis. Percentage analysis and the graphical representation were carried out using MS Excel. During 1984 to 2014 the average annual rainfall was 1293 mm with a coefficient of variation of 22 percent. The rainfall was above normal in 13 years with a deficit in 13 years, and very scarce in five years. The survey revealed that the crop insurance, cultivation of short duration crops, cultivation of drought tolerant rice varieties, inter cropping, changing the planting and harvesting date and agro forestry were some of the adaptation strategies practiced by farmers in the study area. The percentage analysis revealed that 94% of the farmers had crop insurance, 90 % of the farmers cultivated short duration crops, 72% of the farmers switched to cultivation of drought tolerant varieties, 46% of the farmers practiced intercropping, 30% of the farmers changed the planting and harvesting date, and 28% of farmers practiced agro forestry strategy as adaptation measures for climate change. Though the farmers in the study area practiced these climate change adaptation strategies to some extent, dissemination of knowledge about appropriate adaptation strategies towards farming community is essential to protect the livelihood of the farm households, while ensuring the food security of the country. Thus, the farmers may be given proper support by supplying short duration and drought tolerant rice varieties and selected seedlings for agro forestry.
Applicability of colorimetric organic matter determination and its relationship with total soil nitrogen for selected soils in Sri Lanka
(University of Peradeniya, Sri Lanka, 2015-11-06) Darshana, E.M.A.; Nandasesna, K.A.
Soil Organic matter determination using Colorimetric determination is a simple and less time consuming method which has not been tested for Sri Lankan soils yet. Soil Organic matter determination using Walkey and Black method (Volumetric determination) is a very common method. It is more laborious, time and chemical consuming. Relationship between soil Nitrogen level and colorimetric soil organic matter content is also useful to predict soil Nitrogen level. The objectives of this study were to investigate the applicability of colorimetric determination of soil organic matter to Sri Lankan soils and to investigate the relationship between soil Nitrogen and soil organic matter. Fourteen soils, varying in C content, were collected from agricultural fields at 0-30 cm depth differing in physico-chemical and other characteristics. In colorimetric method, 1 g soil samples were placed in 100 ml volumetric flasks followed by the addition of 10 ml of 1/6 N K₂Cr₂O₇ and 20 ml of concentrated H₂S0₄. The samples were mixed by swirling the flask and then and allowed to stand on a pad for 30 minutes in a fume cupboard. After bringing to a volume of 100 ml, the mixture was filtered and analyzed for light absorption at 600 nm using spectrophotometer. Colorimetric organic matter values showed strong correlation with organic matter determined by volumetric (Walkey and Black, 1934) method (r=0.95). Organic matter determined from both methods showed no significant difference. Colorimetric method organic matter values showed strong correlation with total Nitrogen (r=0.75). It is confirmed that colorimetric method can be used effectively and reliably to determine soil organic matter in Sri Lankan soils and total Nitrogen in soil can also be predicted.
Assessment of green space in the colombo city liaisons with gis and in-situ data
(University of Peradeniya, Sri Lanka, 2015-11-06) Madurapperuma, B.D.; Kuruppuarachchi, K.A.J.M.
Urban sprawl in Colombo City is increasing due to centralization of social and economic endeavors. Urban forests and green infrastructure make the city cleaner and healthier to raise the standard of environment quality and aesthetic beauty. This study examines the green urban space in Colombo City using geographic information system and green cover was compared with in-situ ground truthing data in selected locations. A supervised learning algorithm was adopted to classify ESRI base image to three major land-use/cover classes: green space, built-up and water using training samples within Colombo City. Landsat 8 satellite imagery that acquired on 14.04.2015 was used to calculate Normalized Difference Vegetation Index (NDVI). Then green space of the NDVI image was extracted using polygonal vector feature class of the classified image. The results showed that 29% of the area was green space, 67% was built-up and 4% was water. Coefficient of agreement (Khat) was calculated for the classified image resulting in 0.81 overall accuracy. The NDVI values showed the intensity of greenness of vegetation. The difference of NDVI values were compared using available base maps. Then NDVI results were utilized to assess the green space in the field systematically to gauge how species contributes for varying greenness. The results and the method adopted in this study eventually provide valuable insights for city planners and policy makers to establish new green urban space to uplift environmental quality of potential sites in Colombo City.
Preliminary study on use of activated coconut coir as adsorbent for removal of chloride and fluoride in water
(University of Peradeniya, Sri Lanka, 2015-11-06) Bandara, H.K.M.S.N.; Kottegoda, N.; Perera, A.D.L.C.
Chlorine is a powerful germicide used in killing many disease-causing microorganisms in drinking water and reducing them to almost non-detectable levels. However, it can react with organic matter in the water and form dangerous, carcinogenic trihalomethanes if present in excess. Fluoride has beneficial effects on teeth at low concentrations in drinking-water, but excessive exposure to fluoride in drinking-water, or in combination with exposure to fluoride from other sources, can give rise to a number of adverse effects. This is a preliminary study to investigate the ability of activated coconut coir (ACC) to remove Cl ⁻ and F⁻ anions in water. Coconut coir, a lignocellulosic polymer, was activated by treating with phosphoric acid followed by pyrolysis and used as an adsorbent for the removal of Cl⁻ and F⁻ anions from an aqueous solution. Activated product was characterized by Fourier Transform Infrared (FT-IR) Spectroscopy, Scanning Electron Microscope (SEM) and X-ray diffraction techniques and adsorption capacity was measured using methylene blue number. Chloride and fluoride ion removal ability of activated coconut coir was studied by using standard salt solutions of KCl and NaF, respectively. The concentration of Cl⁻ was determined using chloride ion selective electrode and that of F⁻using SPADNS (sodium-2-(parasulfophenylazo)-1,8-dihydroxy-3,6-napthalene) reagent. After activation, coconut coir gains more porosity and adsorption capacity. This can be attributed by the high Methylene Blue (MB) number of 331.30 mg g⁻¹obtained for ACC. The FT-IR data indicates appearance of new functional groups such as carboxylate and phosphate after activation process. The Powder X-Ray Diffraction pattern of synthesized ACC sample showed a peak at an angle of 2θ = 24° corresponding to the hexagonal graphitic carbon structure of (002) plane. The surface morphology and pore structures were analyzed using SEM; SEM images of activated product showed pores in the nanometer size scale. The Presence of nanometer size pores introduces higher adsorption capacity into the ACC. The maximum percent removal of Cl⁻ observed was 30% and that of F- was 40% in single filtration. The equilibrium adsorption studies of Cl ⁻ and F ⁻ anions show that experimental data fits well to linear forms of both Freundlich and Langmuir isotherms implying homogenous and monolayer coverage. The Langmuir constant for Cl ⁻ was 388.00 dm³ g⁻ ¹ and that for F ⁻ was 420.00 dm³ g⁻ ¹ The Freundlich constants for Cl⁻ and F⁻ were 0.022dm³ g⁻ ¹ and 0.012dm³ g⁻ ¹, respectively. The phosphoric acid activated coconut coir has the potential to be used as low-cost adsorbent for the removal of Cl⁻ and F⁻ anions from water.
Modelling the temporal dynamics of soil moisture content of a yellow latosol
(University of Peradeniya, Sri Lanka, 2015-11-06) Gierthana, M.; Vitharana, U.W.A.; Suthakar, S.
Soil moisture is a key variable that control exchange of water and heat between the land surface and atmosphere. Knowledge on the dynamics of soil moisture and there management are paramount steps to improve crop production. In this study, a simple hydrological model was assessed to estimate the temporal dynamics of soil moisture content of a Yellow Latosol at Regional Agricultural Research and Development Centre in Kilinochchi. The input parameters required for the model (Chopra model) are initial soil moisture and surface boundary flux conditions along with few easily measurable soil physical parameters. This model also predicted the soil moisture contents at different depth intervals and at different time intervals. To investigate functioning of the model, input data were obtained from available literature databases, laboratory analysis and pedo-transfer functions. Soil samples were collected at the depth of 0-15 and 15-30 cm every morning at same time for a twenty days period from each location for moisture content measurements. Measured and predicted moisture contents of the surface soil were compared using root mean square error (RMSE) and residual error (RE) values. The result indicated that the RMSE values for modelled moisture content were within the range 0.02 to 0.08 and the RE values from 2 to 8%. When input data from three different sources were used the residual error is less than 10%, which is reported as an acceptable level of prediction accuracy. This model produced most accurate predictions when the values of input parameters from laboratory analysis were used. Hence, this model can be applied to generate temporal dynamics of soil moisture data with an acceptable accuracy for agricultural purposes.
Communication and adoption of waste management practices of urban and semi-urban households in Trincomalee district
(University of Peradeniya, Sri Lanka, 2015-11-06) Ganegoda, P.; Wanigasundera, P.
Waste disposal has become a serious issue in Sri Lanka, making her one of the highest waste generating countries in Asia. Previous research findings state that the key to successful waste management system is the cooperation of citizens, which could only be gained through public awareness, which is lacking in Sri Lanka. Thus, the focus of this research was to find out the role communication has in creating awareness and promoting adoption of waste management practices. Moreover, the research specifically focused on finding out the communication channels by which people receive information of waste management and the message content of those channels affecting the level of awareness and adoption of waste management practices. The data gathered from three purposively selected Divisional Secretariat divisions based on the ethnicity, as the study area is a multi-ethnic area; 200 households were selected randomly from both urban and semi-urban GS divisions. Trincomalee Town and Gravets and Kinniya DS divisions, which are functioning under the urban councils, represent the majority of Tamil and Muslim populations, respectively, whereas Kanthale DS division functions under Pradeshiya Sabha represents majority of Sinhala population. Data were gathered using a questionnaire and analyzed using Statistical Package for Social Sciences. Results revealed that people received messages related to waste management by around 20 communication channels, which can be categorized into three: national mass communication channels, provincial formal communication channels, and informal communication channels. Among them, mostly used communication channel was the television. In addition, respondents used Public Health Inspectors, school education, Urban Council/Pradeshiya Sabha, and newspapers to receive information. However, a large amount of information respondents received was not directly related to waste management. The information received through school education, television, newspaper and non-governmental organizations showed a significant positive impact on awareness level, but, only school education had a significant positive impact on adoption level. In conclusion, the results emphasize that communication plays a major role in creating awareness of people regarding waste management. However, it alone cannot contribute to improve the adoption level, which requires the contribution of supporting services, such as the service of informal waste collectors and implementing rules and regulations.
Soil moisture response to convective rainfall
(University of Peradeniya, Sri Lanka, 2015-11-06) Nianthi, K.W.G.R.; Wickramagamage, P.; Rambukkange, M.P.
The climate of Sri Lanka is tropical monsoonal with a marked seasonal rhythm in rainfall. This rhythm is also reflected in the soil moisture because rainfall influences the soil water content. Soil moisture is known to play an important role in our environment and is thus considered an important climatic variable. Therefore, determining the relationship between soil moisture and rainfall are needed to characterize the climate variability. The usual practice is to use long term measurements of rainfall and soil moisture content to derive rainfall-soil moisture relationships. However, results obtained from long-term can obscure the short term behavior of a soil. High temporal resolution rainfall and soil moisture data from first inter monsoon season are used to investigate the response of soil moisture to individual rainfall events. High temporal resolution data are collected at the weather station of the Department of Geography. The moisture sensor is buried at 30 cm depth to capture the soil moisture in the effective root zone. The soil moisture variations during rainfall were investigated for April 2015. The study focuses on the response of soil moisture to individual rainfall events of different magnitudes and durations. There were 20 major rainfall events during the study period. An individual rainfall event and its corresponding moisture curves were observed. About 45% of rainfall events in April lasted for less than 30 minutes while 30% of the showers lasted for over an hour. In many cases, the peak rainfall occurred about 15 minutes after the beginning of a shower. High rainfall amounts usually triggered a peak in the soil moisture curve. The maximum observed soil moisture level was about 47%. Two types of soil moisture peaks were identified in the time series: sharp-pointed peaks and flat topped-peaks. The latter condition occurred during very long rainfall and/or large rainfall magnitudes. The soil moisture level at the beginning of the month of April was about 2.8%, but thereafter it did not fall below 6% during the rest of the month. This increase in minimum soil moisture level is most likely due to the cumulative effect of rainfall. Although approximately 35% of the showers had total rainfalls of less than 10 mm, the remainder of showers had higher rainfall amounts. These episodes were responsible for maintaining higher soil moisture levels and even driving the soil moisture to the saturation level. This study reveals that a small rainfall amount with a long duration or large rainfall amount with short duration can lead to soil water saturation. Most of the rainfall events were short (< 2 hours) and a majority of them (60%) occurred in the afternoon suggesting convective rainfall. The study reveals that approximately 15 mm of total rainfall is necessary to get soil moisture to saturation. This implies that rainfall duration is a critical factor in driving the soil moisture to saturation. It is apparent that rainfall duration of less than 30 minutes does not lead soil moisture to saturation. Frequent intermittent rainfall events during the month of April contributed to the overall increase in the soil moisture level compared to the previous month. This elevation in the soil moisture level could also have a significant impact on plants.
Very low frequency electromagnetic (vlf em) method for vein graphite investigation in crystaline rock terrain : a case study in Rangala, Sri Lanka
(University of Peradeniya, Sri Lanka, 2015-11-06) Karunarathne, K.M.P.C.; Dharmagunawardhane, H.A.
Vein graphite formations in Sri Lanka show systematic orientation rather than random. They follow define brittle structures alone in mineralized regions, but pinching out behaviour of veins make them difficult to be detected by traditional drilling methods. At present, exploration for new graphite veins is important factor for continuation of graphite industry. Electromagnetic Surveys are some of the most common survey methods in globe for the conductive mineral exploration. A Very Low Frequency (VLF) electromagnetic survey was carried out using EM 16 handheld instrument for the field data collection. Rangala graphite mine area is situated in the Kegalle district within the crystalline terrain of Sri Lanka. Survey grid was designed perpendicular to the primary signal transmitting direction. Positive to negative inphase reading variation along survey lines was used as primary indication of subsurface conductor. Simple numerical filtering method was used to reduce random fluctuation of the anomalies. Interpretation of individual anomalies indicated that the conductive zones present at an average depth of 10m-15m. These anomalies have followed vein orientation of NW-SE as shown by previous investigators. Overlapping of anomalies with already identified veins and drill hole data verified relationship between anomalies and graphite veins. At least fourteen conductive bodies were identified during the study, indicative of graphite veins. According to the anomalies, lengths of the veins vary between 20m-150m with steep dipping. VLF anomalies indicated a very significant correlation with the already located graphite veins, thus conforming the other anomalies represent yet undiscovered graphite veins. The study further revealed that VLF method can be effectively and economically used in graphite exploration in Sri Lanka, instead of costly drilling based investigations.
Assessment of nitrogen, phosphorous and potassium concentrations in different raw material vermiwash
(University of Peradeniya, 2015-11-06) Dilani, P.G.I.L.; Loganathan, P.
The study was carried out from November 2014 to April 2015 within the premises of Vavuniya Campus of University of Jaffna. The main objective of this study was to analyze nitrogen, phosphorus and potassium (NPK) concentrations of vermiwash (VW) prepared with different raw materials. Study was targeted on several other objectives such as to seek the handiness of recycling vegetable waste and mango leaves through VW preparation, to prepare VW from green plant species which cause trouble in the environment. Five plastic barrels were used to establish the vermi-bed. A tap was fixed at one horizontal limb of the container. Then, a base layer of small gravels was placed. Over that a layer of fine sand was placed. Then, a layer of top soil was added and it was covered with a layer of cow dung. Excess amount of water was sprayed and allowed to drain-off. After that the tap was closed. Four different types of raw materials, namely vegetable waste, mango (Mangifera indica) leaf litter, parthenium (Parthenium histeroporous) and water hyacinth (Eichhornia crassipes) were used for the preparation of VW. Control unit was maintained. In control, only top soil and cow dung bed were used without adding any extra feeding material. Locally available Earth worms (EWs) were collected from an open land field of Agriculture School in Vavuniya, where livestock wastewater discharges. Fifty surface and subsurface local EWs were introduced in to each vermi- bed. After 60 days of processing, 4.5 L of VW from each unit was collected after passing 5 L of water into each unit. Three samples from each Vermiwash preparation unit and control were collected for physiochemical analysis. Physiochemical characteristics of different raw material driven VW were analyzed using one-way ANOVA. Significant differences were observed between different raw material driven VW and control, including available nitrogen (P ≤ 0.0001), available phosphorous (P ≤ 0.0001), exchangeable potassium (P ≤ 0.0001). Highest concentrations of nutrients were recorded in Parthenium VW (highest ) and Vegetable waste VW (highest and highest K+). The pH of VW was slightly alkaline (7.6 – 8.4). Vermiwash with 1:5 dilution (V/V) was lying within a range of 7.1 - 7.4. Near neutral range of 5.5 - 8.5 is suitable for crop foliar spraying solutions. EC range of 0.5 –1.5 dS/m in soil indicates suitable condition for cropping. Electrical Conductivity (EC) of different types of VW with 1:5 (V/V) dilutions was confirmed range from 0.7 – 1.4 dS/m. This study confirmed feasibility of VW preparation with environmentally troublesome weeds (Parthenium and Water hyacinth). The vermiwash contains considerable concentrations of nutrients in it. Vermicomposting is increasingly becoming popular as an organic solid waste management strategy. The preparation of VW with selected raw material confirmed alternative solution for controlling vegetable waste and mango leaf litters because there is no garbage after prepared VW. The amounts of nutrients in VW will be sufficient to apply for leafy vegetables where low chemical fertilizer applications are prescribed. There is still a requisite of continuing study in this field ahead to, compare the effectiveness of VW application on crop growth with recommended chemical fertilizer application. That will find whether VW replace the chemical fertilizers fully or partially; and to confirm relationship between nutrients concentration in pure raw materials and after it is proceeded in to Vermiwash.
Spatial variability of selected soil chemical properties for agricultural land management
(University of Peradeniya, Sri Lanka, 2015-11-06) Aashifa,M.A.R.; Loganathan,P.
Soil spatial variation data of chemical parameters are needed for better agricultural management, sustainable land use management and soil conservation. There is a need to produce accurate soil maps of chemical parameters cost effectively. This study was undertaken to quantify spatial variability of soil properties by a kriging method. Seventy sampling points were selected for this research using stratified random sampling method. Stratification was based on the type of land cover patterns, which were designated as forest patches, agriculture land patches, grass land patches and catchments. Sampling points were randomly selected from each land cover type. Minimum distance between two adjacent sampling points was 500 m. Soil samples were analyzed for pH, EC, exchangeable K and available P. In each location, soils were collected from top to - 30 cm depth (root zone) using a core sampler and sub soil samples were collected around the geo- referenced point to obtain a composite sample. Geostatistical software was used to construct semi- variograms and spatial structure analysis for the variables. Geostatistical estimation had done by kriging. Acidic soil was identified in agriculture land around 13% of area, 6% alkaline soil, and 13% of agriculture land area was identified as saline soil. Accordingly, 32% of agriculture land area was identified as problem soils. Fourteen percentage of agriculture lands contain more available P concentration than the optimum range of 15- 22 ppm and 4% agriculture lands contain higher exchangeable K concentration than the optimum range of 78-97.5 ppm suitable for crop cultivation. Ninety eight percentage of forest lands and 100% of grass lands contain available P concentration higher than the optimum range. But forest lands and catchments showed lower level of exchangeable K concentration. Twenty percentages of grass lands contain higher exchangeable K than the optimum level. Agriculture practices leads to changes in the soil. Hence, identified soil problems should be reclaimed to maintain the fertility of soil for sustainable production. Proper management of soil can be a better solution for supporting the successful agricultural activity of a community in future and socio-economic development in a sustainable way.
Geostatistical mapping of selected soil chemical properties in red latosols of Sri Lanka
(University of Peradeniya, Sri Lanka, 2015-11-06) Eranga, R.L.A.A.; Karunaratne, S.B.; Abeysinghe, D.C.; Gajanayake, B.
Soils are highly variable even at the field scale and detailed studies of spatial variability of soil properties across the landscape are important to manage soils in a sustainable manner. Geostatistics enables to quantify the spatial variability and subsequently prepare detailed digital soil maps. In this study, an attempt was made to quantify the spatial dependence and map the selected soil chemical properties (viz. pH, exchangeable potassium (K) and available phosphorus (P)) in Red Latosols of Sri Lanka. As the study site, a sub set of 22 ha was selected from the cashew seed garden in Elluwankulama, Puttalam District managed by Sri Lanka Cashew Corporation. A design-based sampling scheme namely stratified random sampling was adopted in order to collect soil samples. The stratification was carried out using compact geographic stratification using k-means clustering algorithm and study site was divided in to five strata. Total of 100 sampling locations were sampled where 20 sampling locations were allocated to each stratum. For each considered soil chemical property we deployed a geostatistical approach to create higher resolution digital soils maps and to quantify the spatial distribution of respective soil chemical properties across the study site. The geostatistical models were cross validated and calculated mean error (ME) and root mean square error (RMSE) in order to assess the model quality. Spatial model quality results obtained from the cross validation analysis revealed that, calculated ME values for soil pH (0.002) exchangeable K (0.403 ppm), and available P (0.004 ppm) were closer to zero which suggests unbiased estimation. In case of RMSE, all considered soil chemical properties reported lower values, which includes for soil pH (0.354), exchangeable K (13.581 ppm), and available P (1.673 ppm), respectively suggesting accurate estimation. In analysis of spatial dependence, nugget-to-sill ratio showed strongly structured spatial dependencies with negligible random variations for all considered soil chemical properties. Results further revealed that spatial correlation (range parameter) of pH, exchangeable K and available P reported as 31 m, 98 m and 54 m, respectively. This information is vital to carry out future soil sampling of Red Latosols in order to optimally characterize the spatial variability of considered soil chemical properties by maintaining sampling interval within the estimated range parameter. Furthermore, it was indicated that pH values in most areas of the study site varied from very strongly acidic (4.5) to strongly acidic (5). The exchangeable K and available P levels are mainly distributed within fairly low (58.5-78 ppm) to medium (78-97.5 ppm) and fairly low (7.5-15 ppm) categories, respectively. Maps produced in this study provide valuable information on spatial distribution of considered soil chemical properties including nutrient status within the study site that can be used as a guide to conduct site specific fertilizer applications, intercropping and other management practices, in an environmental friendly manner.
Development of land suitability map to expand rubber in northern dry zone of Sri Lanka : a case study from Vavuniya district
(University of Peradeniya, Sri Lanka, 2015-11-06) Liyanaarachchi, L.A.T.S.; Karunaratne, S.B.; Sankalpa, J.K.S.; Wijesuriya, B.W.; Gajanayake, B.; Abeysinghe, D.C.
The land extent of traditional rubber growing areas in the Wet Zone of Sri Lanka is limited due to various development activities. Therefore, expansion of rubber into non-traditional areas is vital to increase the extent under rubber cultivation and to meet the production target of the country. This study was aimed at developing a land suitability model and using it for mapping of potential areas where rubber can be cultivated in the Dry Zone of Sri Lanka considering a case study from Vavuniya District. Weighted overlay analysis in Geographic Information System (GIS) environment was carried out to develop a land suitability model where weights for the main variables namely; annual cumulative rainfall, maximum and minimum temperatures, elevation, slope of the land and soil type were determined using Analytical Hierarchical Process (AHP). Once the land suitability map was derived, potential land areas where rubber can be cultivated in the district were identified. Results of the AHP revealed that rainfall, minimum temperature, maximum temperature, slope, elevation and soil type were allocated weights of 39%, 7%, 15%, 6%, 5% and 28%, respectively in the land suitability model. Furthermore, results revealed that out of total potential land for expansion of rubber cultivation in the Vavuniya District, 19,751 ha of land were “Moderately suitable” while 3,297 ha of lands were categorized under “Unsuitable” and “Most unsuitable”. As the Vavuniya District has no optimum soil condition for rubber cultivation, proper ways of amending soils should be carried out. The outputs generated from this study provide firsthand information for policy makers related to expansion of rubber in the Northern Dry Zone of Sri Lanka.
Evaluation of the status in environmental flow maintainance at mangalathiriya anicut in Aththanagalu oya, Sri Lanka
(University of Peradeniya, Sri Lanka, 2015-11-06) Udayanga, N.W.B.A.L.; Najim, M.M.M.
Determination of the volumes of flows that should be maintained for the sustenance of the natural eco systems under pristine conditions (Environmental Flows [EF]), remains complicated and difficult, causing a challenging situation for the sustainable management of water resources in many countries. As a tropical developing country with agriculture based economy, Sri Lanka is in need of utilizing the available lentic and lotic water sources heavily to support its economy. Yet, the management of such water sources in an ecofriendly sustainable manner without significantly affecting, both the environment and the economy, requires the maintenance of environmental flows. Thus, the quantification and long-term maintenance of EF requirements of lotic waters has emerged as a crucial requirement in sustainable management of water resources. Therefore, the Range of Variability Approach (RVA) was devised to evaluate the sufficiency of the flows at the downstream of the Mangalathiriya anicut for the sustenance of downstream riverine ecosystems. The Hydrologic Engineering Centre - Hydrologic Modelling System (HEC-HMS) version 3.5 model was calibrated and validated for the Aththanagalu Oya catchment and the daily river flow values for the past twenty years (1994-2014) were generated at the pre weir of the Mangalathiriya anicut. The downstream flows were calculated by deducting the drinking water requirements of the anicut. The existing flow regime at the post-weir was subjected to a RVA analysis, while utilizing 32 different hydrological parameters. The RVA targets (set based on the flows of pre weir site) and rate of non-attainment (for the flow at the downstream of the weir of Mangalathiriya anicut) were calculated to evaluate the sufficiency of the downstream flow regime to cater the EF requirements of downstream ecosystems. The rate of non-attainment of the IHA group 1 and group 2 parameters range in between 33 - 100 % suggesting a moderate to severe level of ecological degradation of the downstream ecosystems. In the IHA group 3, inability of calculating the timing of lower limit of annual extreme water condition due to the prevalence of similar minimal flow levels for several days forced the annual minima to be left uncalculated. Yet the annual maxima reflect a rate of non- attainment of 43 %, while the rate of non-attainment of both IHA group 4 and 5, range in between 48 - 100% and 53 - 100 %, respectively suggesting an ecological degradation of moderate to severe degree. Furthermore, the mean rate of non-attainment of 57.15 % predicts an overall moderate degree of ecological degradation of downstream ecosystems due to the operation of the Mangalathiriya anicut of Aththanagalu Oya. Thus, the results of the current study emphasizes that an adequate level of EF regime is not maintained at the downstream of the Mangalathiriya anicut in Aththanagalu Oya in accordance with the RVA.
Effect of biochar on phosphorus availability and fixation in some rubber (hevea brasiliensis) growing soils of Sri Lanka
(University of Peradeniya, Sri Lanka, 2015-11-06) Nandasena, M.A.G.H.; Dharmakeerthi, R.S; Herath, H.M.S.K.
In most rubber [Hevea brasiliensis (A. Juss.) Muell. Arg.] growing soils, phosphorus (P) availability is very low and added P fertilizers become unavailable to the rubber plant due to strong fixation of it into Fe and Al oxide minerals prevalent in these soils. Some studies have observed that amending soils with biochar (BC), a co-product of thermochemical conversion of lignocellulosic materials into advanced biofuels, has increased the P uptake and cut down chemical P fertilizer usage in rubber nursery plants. Therefore, a laboratory incubation study was undertaken to determine the dynamics of soil P availability in three rubber growing soils amended with BC made from rubber wood (RWBC). Three soil types, i.e. Reddish Brown Latasolic (RBL) soil from Parambe, Reddish Brown Earth (RBE) soil from Thanamalwila, and Red Yellow Podsolic (RYP) soil from Payagala were amended with RWBC at 0, 2 and 5% by weight. The soil moisture content was maintained at 80% of water holding capacity and P availability was determined at 0, 1, and 4 weeks during the incubation period. P fixation of soils amended with RWBC was assessed using the Portch and Hunter (2002) method. Available P contents were very low (4.1 to 10.7 ppm) in the three soils and was in the order RYP < RBE < RBL. Application of RWBC increased the available P content by 3 to 7 folds and the increase was in the order of RBE < RBL < RYP. The available P content decreased with incubation time and the greatest decrease (52%) was in RBL while the lowest (42%) was in RBE soil at 4 weeks after incubation in 5% BC amended treatments. Among the three soil types studied the RYP soil had the lowest P fixation ability, while RBL was the highest P fixing soil. Application of BC decreased the P fixation in RBE and RBL soils but not in RYP soil. The greatest decrease was observed when RWBC was applied at 5%. Therefore, amending rubber growing soils with RWBC appears to have altered the dynamics of available P in a positive manner.

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