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Physical Sciences and Mathematics Commons

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University of Arkansas, Fayetteville

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

Environmental Health and Protection

Articles 1 - 3 of 3

Full-Text Articles in Physical Sciences and Mathematics

Earthworm Populations In A Wheat-Soybean Double-Crop System Under Seven Years Of Established Residue Management Practices, Jill Thomason, Mary Savin, Kristopher Brye, Donn T. Johnson Jan 2015

Earthworm Populations In A Wheat-Soybean Double-Crop System Under Seven Years Of Established Residue Management Practices, Jill Thomason, Mary Savin, Kristopher Brye, Donn T. Johnson

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

Earthworms improve soil structure, distribute litter and microbes, stimulate microbial activity, facilitate decomposition, and increase nitrogen (N) availability for plant growth. Earthworm density is often reduced in low organic matter soils that are intensively managed to grow row crops. This study was designed to relate earthworm density and community composition to residue management after seven years of established management practices in a wheat (Triticum aestivum L.)-soybean (Glycine max (L.) Merr.) double-crop system maintained in Marianna, Ark. Residue management practices included conventional tillage (CT) and no-tillage (NT), N fertilization to produce high and low wheat residue amounts left in the field, …


Effects Of Diesel And Biodiesel Blends On Engine Performance And Efficiency, Christopher Hunt, Donald Johnson, Don Edgar Jan 2010

Effects Of Diesel And Biodiesel Blends On Engine Performance And Efficiency, Christopher Hunt, Donald Johnson, Don Edgar

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

Tests were conducted during the summer of 2009 on a John Deere 3203 diesel tractor to determine differences in specific fuel consumption (sfc), power take-off (PTO) torque (Nm), and PTO power (kW), between ultralow sulfur No. 2 Diesel (D2), 20% biodiesel (B20), 50% biodiesel (B50), and100% biodiesel (B100). Four 1-hr tests were conducted with D2, while three 1-hr tests were conducted with B20, B50, and B100. The results indicated that there was no significant (p < 0.05) difference between D2 and B20 for power or torque. Fueling with B50 resulted in significantly lower power and torque than fueling with D2 or B20, but significantly higher power and torque than fueling with B100. There were significant differences between each fuel in sfc; as the biodiesel blend increased, sfc also increased. Based on these data, B20 appears to be the optimal biodiesel blend for this and similar compact utility tractors since fueling with B20 resulted in no significant loss in power or torque (compared to D2) and only a slight increase in fuel consumption.


Life Cycle Analysis For The Cultivation And Combustion Of Miscanthus For Biofuel Compared With Natural Gas, Amanda Ashworth, Charles West, Michael Popp, Mireille Montrejaud-Vignoles, Caroline Sablayrolles, Gabrielle Benoit Jan 2008

Life Cycle Analysis For The Cultivation And Combustion Of Miscanthus For Biofuel Compared With Natural Gas, Amanda Ashworth, Charles West, Michael Popp, Mireille Montrejaud-Vignoles, Caroline Sablayrolles, Gabrielle Benoit

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

As negative environmental and economic impacts of fossil fuels have escalated, so has the importance of renewable bioenergy crops whose feedstocks are noncompetitive with food supplies. Compared with fossil fuels, use of lignocellulosic feedstocks offers potential for greenhouse gas reduction and highly positive net energy returns because of low input demand and high yields per unit of land area, thus making them advantageous for the emerging biofuel industry. The aim of this study was to simulate environmental impacts of producing a biofuel grass for combustion use based on the inventory of inputs and their effects on eutrophication of surface waters; …