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Physical Sciences and Mathematics Commons

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Full-Text Articles in Physical Sciences and Mathematics

Regenerating Agricultural Landscapes With Perennial Groundcover For Intensive Crop Production, Kenneth J. Moore, Robert P. Anex, Amani E. Elobeid, Shuizhang Fei, Cornelia B. Flora, A. Susana Goggi, Keri L. Jacobs, Prashant Jha, Amy L. Kaleita, Douglas L. Karlen, David A. Laird, Andrew W. Lenssen, Thomas Lubberstedt, Marshall D. Mcdaniel, D. Raj Raman, Sharon L. Weyers Aug 2019

Regenerating Agricultural Landscapes With Perennial Groundcover For Intensive Crop Production, Kenneth J. Moore, Robert P. Anex, Amani E. Elobeid, Shuizhang Fei, Cornelia B. Flora, A. Susana Goggi, Keri L. Jacobs, Prashant Jha, Amy L. Kaleita, Douglas L. Karlen, David A. Laird, Andrew W. Lenssen, Thomas Lubberstedt, Marshall D. Mcdaniel, D. Raj Raman, Sharon L. Weyers

Douglas L Karlen

The Midwestern U.S. landscape is one of the most highly altered and intensively managed ecosystems in the country. The predominant crops grown are maize (Zea mays L.) and soybean [Glycine max (L.) Merr]. They are typically grown as monocrops in a simple yearly rotation or with multiple years of maize (2 to 3) followed by a single year of soybean. This system is highly productive because the crops and management systems have been well adapted to the regional growing conditions through substantial public and private investment. Furthermore, markets and supporting infrastructure are highly developed for both crops. As maize and …


Winter Grazing Management, Stephen K. Barnhart, James R. Russell, Douglas L. Karlen, Michael J. Tidman Jun 2017

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 Dec 2015

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 Dec 2015

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 Dec 2015

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% …


Evaluation Of Tillage And Crop Rotation Effects On Groundwater Quality—Nashua Project, Rameshwar S. Kanwar, Douglas Karlen, Thomas S. Colvin, William W. Simpkins, Vince J. Mcfadden Dec 2015

Evaluation Of Tillage And Crop Rotation Effects On Groundwater Quality—Nashua Project, Rameshwar S. Kanwar, Douglas Karlen, Thomas S. Colvin, William W. Simpkins, Vince J. Mcfadden

Douglas L Karlen

Sampling shows that agricultural chemicals are occurring increasingly in ground- and surface water in Iowa. The same trend has been reported throughout the United States; one study reported finding 73 pesticides in the groundwater of 34 states. Even pesticides known to be adsorbed to soil particles (and thus relatively immobile) have been found in a few sampled wells in trace concentrations. Nitrate-nitrogen (NO3-N) is the most common agricultural chemical found in groundwater. Nitrogen fertilizers and pesticides applied to the soil surface prior to and immediately following crop planting are particularly susceptible to surface runoff or leaching to groundwater through the …


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 Dec 2015

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.