Economic Analysis of Jatropha Bio-diesel Production in Sri Lanka

There has been an increasing trend in investments in renewable energy sources in the recent years. This study assesses the economic and financial feasibility of Jatropha production in Sri Lanka under the prevailing policy regime. The nominal protection coefficient and effective protection coefficients were employed to gauge the level of protection for bio-diesel production using Jatropha in Sri Lanka. The cost benefit analysis was performed to assess the feasibility of Jatropha bio-diesel production in Sri Lanka. The conventional measures like NPV, BCR, and IRR were used in financial and economic terms. Nominal Rate of Protection (NPR) was calculated by dividing the local Jatropha bio-diesel price by the border price of biodiesel. The NPR for Bio-diesel implies that nearly 47% of protection at local market level. Effective Protection Rate (EPR) for seed production is 90%, for oil extraction and bio diesel processing it is 128%. Implication of this is that the producers will be protected and they receive returns 47% greater than what they would have received under free market conditions for Jatropha cultivation. Except for the benchmark situation, all other considered scenarios produce a favourable NPV, BCR and IRR for Jatropha bio-diesel production. Economic benefits due to CO2 reduction were also considered in the analysis.KEYWORDS:Cost benefit Analysis, Jatropha Biodiesel, Protection Coefficien

Potential of utilizing ground-penetrating radar to calibrate electromagnetic induction for shallow soil water content estimation.

Hydro-geophysics uses near-surface geophysical techniques such as ElectromagneRc InducRon (EMI) and Ground-PenetraRng Radar (GPR) to determine the spaRotemporal variability of soil water content (SWC) in the agricultural landscape. Compared to standard methods, EMI and GPR can be used for large scale mapping of SWC non-destrucRvely. EsRmaRon of SWC with GPR is straight forward, however, EMI requires a site-specific predicRon model to esRmate SWC, mostly developed by using point scale measurements. Accordingly, the objecRves of this study were to i) correlate the two proxies; GPR direct ground wave velocity (VDGW) and EMI apparent electrical conducRvity (ECa), with SWC measured from Time Domain Reflectometry (TDR), and ii) develop a predicRve model for EMI to esRmate SWC, using GPR. ECa and VDGW data were collected before and afer irrigaRon, using an EMI sensor and two GPR systems with 500 MHz and 250 MHz center-frequency antennas. CorrelaRons were assessed and simple linear regressions (SLR) between EMI and GPR were developed to predict SWC. Strong negaRve correlaRons were found between 500 MHz (r=-0.828, p=0.000) and 250 MHz (r=-0.786, p=0.000) VDGW and TDR at 0-0.2 m depth. ECa from verRcal and horizontal coil orientaRons showed strong posiRve correlaRons (r=0.797, p=0.000 and r=0.878, p=0.000) with TDR measured SWC. SLRs showed higher coefficient of determinaRons (R2 > 0.70) for both coil orientaRons with the 500 MHz antenna. Results showed the potenRal of GPR to calibrate EMI for shallow SWC esRmaRon and future improvements of these predicRon models can be used for large-scale SWC mapping to support precision agriculture

Influence of tillage and soil compaction on the proxies of ground-penetrating radar and electromagnetic induction.

Abstract Soil Rllage and compacRon influence soil properRes and processes like porosity, bulk density, water content, drainage, and infiltraRon which ulRmately affects soil quality and health. Nearsurface geophysical techniques such as Ground-PenetraRng Radar (GPR) and ElectromagneRc InducRon (EMI) are being increasingly uRlized to esRmate soil water content. However, there is a lack of studies examining the role of soil Rllage and compacRon on soil properRes and processes using geophysical proxies. Accordingly, the objecRve of this study was to elucidate the influence of soil compacRon on responses of GPR direct ground wave velocity (VDGW), amplitude (ADGW), and apparent electrical conducRvity (ECa) measured using EMI in a boreal podzolic soil. Proxy data: VDGW, ADGW and ECa, were collected using an EMI sensor and a 500 MHz center frequency GPR system under three stages, i.e., afer Rllage, afer 4- and 10-Rmes roller passes. Undisturbed soil samples were collected to measure bulk density as the soil compacRon index and correlaRons were assessed between proxies and soil bulk density. Moderate posiRve correlaRons were found between average bulk density (0-30 cm depth) and ADGW (r=0.548, p=0.001), and ECa (r=0.633, p=0.001), while a moderate negaRve correlaRon was found between bulk density and VDGW (r= -0.464, p=0.030). Preliminary results reveal that mapping soil bulk density at the field-scale using GPR and EMI can potenRally capture the effects of Rllage or compacRon on the variability of soil bulk density and related properRes or processes. Therefore, the effect of agricultural pracRces on soil properRes can be esRmated non-destrucRvely with proxies of GPR or EMI to advance precision agriculture