ABSTRACT
The demand for organic agriculture has been growing due to concerns about the environmental and health impacts of chemical-intensive farming. The study aimed to investigate the effects organic fertilizers on carrot (Nantes) growth and yield in Tehuledere district. The experiment was conducted at two sites (Gobeya and Libannos) using four fertilizer types (vermicompost, conventional compost, mixture of the two, and inorganic fertilizer) and a control. The experiment was laid out in randomized complete block design with three replications, and data were analyzed using R-software. The study analyzed various growth (emergence percentage, plant height, leaf number, fresh weight, and dry weight of leaves), and yield (root length, root diameter, fresh weight of roots, marketable root yield, unmarketable root yield, and total root yield) parameters. Generally, fertilizer application improved (p < 0.001) growth and yield compared to the control. Vermicompost and inorganic fertilizer (NPSB) showed similar results (p > 0.001) but the highest values (p < 0.001) for most of the parameters (marketable yield was 41.7 t/ha±0.76 for vermicompost and 42.5 t/ha±1.14 for NPSB). However, NPSB could pose negative environmental impact that could not result in sustainability if used in excess and inappropriate (method and time) in particular. Therefore, carrot production using vermicompost is recommended for farmers of Tehuledere district and similar agroecological areas to enhance productivity while contributing to sustainable agriculture. The results have implications for policy makers, researchers, and farmers interested in promoting environmentally friendly and sustainable carrot production.
ABSTRACT
BACKGROUND: Coffee is a well-known beverage that is widely used around the world. Despite the wide use of coffee in Ethiopia, there is a lack of extensive studies addressing the issues related to the caffeine content and hydrogen peroxide antioxidant activity of varieties of coffee types, particularly in Habru woreda, Ethiopia. OBJECTIVE: This study aimed to determine the caffeine content and hydrogen peroxide antioxidant activity of raw and roasted coffee beans collected directly from Habru woreda, North Wollo zone of Ethiopia. METHODS: The study was conducted in Bohoro, Girana, and Wurgisa kebeles of Habru woreda, Ethiopia, by collecting 500 g of green beans of Arabica coffee without considering their variety. Then, the collected beans were divided into raw and roasted coffee to perform aqueous and dichloromethane extraction of their caffeine content and hydrogen peroxide antioxidant activity using UV-Vis spectrophotometry. RESULTS: The amounts of caffeine in aqueous and dichloromethane extraction were in the range of 124.01-191.27 ppm and 145.15-200.09 ppm in raw and roasted coffees, respectively. Using the IC50 value, the hydrogen peroxide scavenging activity of the aqueous phase coffee bean extracts in Bohoro raw, Bohoro roasted, Wurgisa raw, Wurgisa roasted, Girana raw, and Girana roasted coffee were 32.17 ppm, 11.69 ppm, 26.14 ppm, 3.12 ppm, 24.83 ppm, and 11.06 ppm, respectively, while that of ascorbic acid was 6.91 ppm. CONCLUSION: The study showed that the highest amount of caffeine in both aqueous and dichloromethane solvent extraction was found in Bohoro's raw and roasted coffee beans. Also, the amounts of caffeine in all coffee bean samples were safe and the antioxidant activity was excellent. In most of the samples, significant variations in the concentration of caffeine in raw and roasted coffee bean samples were observed in the two extraction solvents.
