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Articles 1 - 8 of 8
Full-Text Articles in Physical Sciences and Mathematics
Harvesting Fertilized Rye Cover Crop: Simulated Revenue, Net Energy, And Drainage Nitrogen Loss, R. W. Malone, J. F. Obrycki, Douglas L. Karlen, T. C. Kaspar, D. B. Jaynes, T. B. Parkin, S. H. Lence, G. W. Feyereisen, Q. X. Fang, T. L. Richard, K. Gillette
Harvesting Fertilized Rye Cover Crop: Simulated Revenue, Net Energy, And Drainage Nitrogen Loss, R. W. Malone, J. F. Obrycki, Douglas L. Karlen, T. C. Kaspar, D. B. Jaynes, T. B. Parkin, S. H. Lence, G. W. Feyereisen, Q. X. Fang, T. L. Richard, K. Gillette
Douglas L Karlen
Harvesting fertilized rye (Secale cereale L.) cover crop has been suggested as a method to increase producer revenue and biofuel feedstock production, but drainage N loss impacts are currently unknown. Using the tested Root Zone Water Quality Model (RZWQM) across several N rates, spring application of 120 kg N ha-1 prior to winter rye harvest reduced drainage N loss by 54% compared with no cover crop and by 18% compared with planted rye that was neither fertilized nor harvested. Estimates of producer revenue and net energy were also positive, with 8.3 Mg ha-1 of harvested rye biomass. …
Future Prospects For Corn As A Biofuel Crop, Kenneth J. Moore, Douglas L. Karlen, Kendall R. Lamkey
Future Prospects For Corn As A Biofuel Crop, Kenneth J. Moore, Douglas L. Karlen, Kendall R. Lamkey
Douglas L Karlen
Ethanol production from corn grain has increased signifi cantly during the past ten years in the US. This increase was driven by government policy guided by the Renewable Fuel Standard (RFS) and embodied in the Volumetric Ethanol Excise Tax Credit and other legislation created to promote a biofuels industry. As corn grain ethanol production approaches the target set out in the RFS, the industry is looking to develop capacity for producing advanced biofuels, primarily from agricultural wastes and dedicated energy crops. The residues remaining following corn harvest have been identifi ed as a voluminous and readily available feedstock for advanced …
Reducing Agriculture's Contribution To Nitrate Contamination Of Surface Waters, Dana L. Dinnes, Cynthia A. Cambardella, Thomas S. Colvin, Daniel B. Jaynes, Douglas L. Karlen
Reducing Agriculture's Contribution To Nitrate Contamination Of Surface Waters, Dana L. Dinnes, Cynthia A. Cambardella, Thomas S. Colvin, Daniel B. Jaynes, Douglas L. Karlen
Douglas L Karlen
One of the most prevalent environmental issues throughout the Midwest is nitrate (N03) contamination of surface waters. Non-point source pollution resulting from nitrogen (N) fertilizer use on artificially drained agricultural land has been identified as a major contributor to this problem. High levels of nitratenitrogen (N03-N) in water supplies pose risks to humans and livestock (Tyson et. al., 1992), and has cost some communities millions of dollars for N03 removal. The city of Des Moines, Iowa alone has spent in excess of 5.3 million dollars, not including labor costs, for nitrate treatment of its drinking waters from 1992-1996 (Graham, 1997). …
Winter Grazing Management, Stephen K. Barnhart, James R. Russell, Douglas L. Karlen, Michael J. Tidman
Winter Grazing Management, Stephen K. Barnhart, James R. Russell, Douglas L. Karlen, Michael J. Tidman
Douglas L Karlen
Why winter grazing? Beef cow herd and sheep flock records show that winter feeding costs are livestock producers' single largest production expense. Managing through winter weather while keeping feeding costs low is an essential part of maintaining a profitable operation. Iowa's climate generally allows forage growth only during a 7-to-8 month period. Extending the grazing of this forage--even an extra 3 or 4 weeks in late autumn and winter--is an economical way to maintain or increase livestock profitability. Some producers extend the grazing season by using stockpiled forage, whereas others use crop residue, and many combine the use of stockpiled …
Influence Of Corn Stover Harvest On Soil Quality Assessments At Multiple Locations Across The U.S., Diane E. Stott, Virginia L. Jin, Thomas F. Ducey, Douglas L. Karlen, Gary E. Varvel, Jane M. F. Johnson, John M. Baker, Shannon L. Osborne, Jeff M. Novak, Paul R. Adler, Greg W. Roth, Stuart J. Birrell
Influence Of Corn Stover Harvest On Soil Quality Assessments At Multiple Locations Across The U.S., Diane E. Stott, Virginia L. Jin, Thomas F. Ducey, Douglas L. Karlen, Gary E. Varvel, Jane M. F. Johnson, John M. Baker, Shannon L. Osborne, Jeff M. Novak, Paul R. Adler, Greg W. Roth, Stuart J. Birrell
Douglas L Karlen
Corn (Zea mays L.) stover has been identified as a biofuel feedstock due to its abundance and a perception that the residues are unused trash material. However, corn stover and other plant residues play a role in maintaining soil quality (health) and enhancing productivity, thus use of this abundant material as feedstock must be balanced with the need to protect the vital soil resource. Plant residues provide physical protection against erosion by wind and water, contribute to soil structure, nutrient cycling, and help sustain the soil microbiota. Replicated plots were established on productive soils at several locations (IA, IN, MN, …
U.S. Billion-Ton Update: Biomass Supply For A Bioenergy And Bioproducts Industry, Robert D. Perlack, Laurence M. Eaton, Anthony F. Turhollow Jr., Matt H. Langholtz, Craig C. Brandt, Mark E. Downing, Robin L. Graham, Lynn L. Wright, Jacob M. Kavkewitz, Anna M. Shamey, Richard G. Nelson, Bryce J. Stokes, William L. Rooney, David J. Muth Jr., J. Richard Hess, Jared M. Abodeely, Chad Hellwinckel, Danial De La Torre Ugarte, Daniel C. Yoder, James P. Lyon, Timothy G. Rials, Timothy A. Volk, Thomas S. Buchholz, Lawrence P. Abrahamson, Robert P. Anex, Thomas B. Voigt, William Berguson, Don E. Riemenschneider, Douglas Karlen, Jane M. F. Johnson, Robert B. Mitchell, Kenneth P. Vogel, Edward P. Richard Jr., John Tatarko, Larry E. Wagner, Kenneth E. Skog, Patricia K. Lebow, Dennis P. Dykstra, Marilyn A. Buford, Patrick D. Miles, D. Andrew Scott, James H. Perdue, Robert B. Rummer, Jamie Barbour, John A. Stanturf, David B. Mckeever, Ronald S. Zalesny Jr., Edmund A. Gee, P. Daniel Cassidy, David Lightle
U.S. Billion-Ton Update: Biomass Supply For A Bioenergy And Bioproducts Industry, Robert D. Perlack, Laurence M. Eaton, Anthony F. Turhollow Jr., Matt H. Langholtz, Craig C. Brandt, Mark E. Downing, Robin L. Graham, Lynn L. Wright, Jacob M. Kavkewitz, Anna M. Shamey, Richard G. Nelson, Bryce J. Stokes, William L. Rooney, David J. Muth Jr., J. Richard Hess, Jared M. Abodeely, Chad Hellwinckel, Danial De La Torre Ugarte, Daniel C. Yoder, James P. Lyon, Timothy G. Rials, Timothy A. Volk, Thomas S. Buchholz, Lawrence P. Abrahamson, Robert P. Anex, Thomas B. Voigt, William Berguson, Don E. Riemenschneider, Douglas Karlen, Jane M. F. Johnson, Robert B. Mitchell, Kenneth P. Vogel, Edward P. Richard Jr., John Tatarko, Larry E. Wagner, Kenneth E. Skog, Patricia K. Lebow, Dennis P. Dykstra, Marilyn A. Buford, Patrick D. Miles, D. Andrew Scott, James H. Perdue, Robert B. Rummer, Jamie Barbour, John A. Stanturf, David B. Mckeever, Ronald S. Zalesny Jr., Edmund A. Gee, P. Daniel Cassidy, David Lightle
Douglas L Karlen
The Report, Biomass as Feedstock for a Bioenergy and Bioproducts Industry: The Technical Feasibility of a Billion-Ton Annual Supply (generally referred to as the Billion-Ton Study or 2005 BTS), was an estimate of “potential” biomass within the contiguous United States based on numerous assumptions about current and future inventory and production capacity, availability, and technology. In the 2005 BTS, a strategic analysis was undertaken to determine if U.S. agriculture and forest resources have the capability to potentially produce at least one billion dry tons of biomass annually, in a sustainable manner—enough to displace approximately 30% of the country’s present petroleum …
Monitoring Soil Quality To Assess The Sustainability Of Harvesting Corn Stover, Douglas L. Karlen, Gary E. Varvel, Jane M. F. Johnson, John M. Baker, Shannon L. Osborne, Jeff M. Novak, Paul R. Adler, Greg W. Roth, Stuart J. Birrell
Monitoring Soil Quality To Assess The Sustainability Of Harvesting Corn Stover, Douglas L. Karlen, Gary E. Varvel, Jane M. F. Johnson, John M. Baker, Shannon L. Osborne, Jeff M. Novak, Paul R. Adler, Greg W. Roth, Stuart J. Birrell
Douglas L Karlen
Harvesting feedstock for biofuel production must not degrade soil, water, or air resources. Our objective is to provide an overview of field research being conducted to quantify effects of harvesting corn (Zea mays L.) stover as a bioenergy feedstock. Coordinated field studies are being conducted near Ames, IA; St. Paul and Morris, MN; Mead, NE; University Park, PA; Florence, SC; and Brookings, SD., as part of the USDA-ARS Renewable Energy Assessment Project (REAP). A baseline soil quality assessment was made using the Soil Management Assessment Framework (SMAF). Corn grain and residue yield for two different stover harvest rates (∼50% …
Winter Grazing Of Corn Residues: Effects On Soil Properties And Subsequent Crop Yields From A Corn-Soybean Crop Rotation, W. Darrell Busby, James R. Russell, Douglas L. Karlen, L. James Secor, Brian Peterson, Carroll Olson, Shawn C. Shouse, Dallas L. Maxwell
Winter Grazing Of Corn Residues: Effects On Soil Properties And Subsequent Crop Yields From A Corn-Soybean Crop Rotation, W. Darrell Busby, James R. Russell, Douglas L. Karlen, L. James Secor, Brian Peterson, Carroll Olson, Shawn C. Shouse, Dallas L. Maxwell
Douglas L Karlen
Corn residues could be a good resource for winter cattle grazing. The study investigates whether winter grazing causes soil compaction and yield reduction in crops that are planted following grazing.