Digital Commons Network^™

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

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 …

Engineering, Nutrient Removal, And Feedstock Conversion Evaluations Of Four Corn Stover Harvest Scenarios, Reed L. Hoskinson, Douglas L. Karlen, Stuart J. Birrell, Corey W. Radtke, Wally Wilhelm

Douglas L Karlen

Crop residue has been identified as a near-term source of biomass for renewable fuel, heat, power, chemicals and other bio-materials. A prototype one-pass harvest system was used to collect residue samples from a corn (Zea mays L.) field near Ames, IA. Four harvest scenarios (low cut, high-cut top, high-cut bottom, and normal cut) were evaluated and are expressed as collected stover harvest indices (CSHI). High-cut top and high-cut bottom samples were obtained from the same plot in separate operations. Chemical composition, dilute acid pretreatment response, ethanol conversion yield and efficiency, and thermochemical conversion for each scenario were determined. Mean …

Protocol For Indicator Scoring In The Soil Management Assessment Framework (Smaf), Brian J. Wienhold, D.L. Karlen, S.S. Andrews, D.E. Stott

Douglas L Karlen

Assessment tools are needed to evaluate agronomic management effects on critical soil functions such as carbon sequestration, nutrient cycling and water partitioning. These tools need to be flexible in terms of selection of soil functions to be assessed and indicators to be measured to ensure that assessments are appropriate for the management goals. The soil management assessment framework (SMAF) is being developed to meet this need. The SMAF uses soil physical, chemical and biological indicator data to assess management effects on soil function using a three-step process for (1) indicator selection, (2) indicator interpretation and (3) integration into an index. …

Review And Interpretation: Nitrogen Management Strategies To Reduce Nitrate Leaching In Tile-Drained Midwestern Soils, Dana L. Dinnes, Douglas L. Karlen, Dan B. Jaynes, Thomas C. Kaspar, Jerry L. Hatfield, Thomas S. Colvin, Cynthia A. Cambardella

Douglas L Karlen

Balancing the amount of N needed for optimum plant growth while minimizing the NO3 that is transported to ground and surface waters remains a major challenge for everyone attempting to understand and improve agricultural nutrient use efficiency. Our objectives for this review are to examine how changes in agricultural management practices during the past century have affected N in Midwestern soils and to identify the types of research and management practices needed to reduce the potential for nonpoint NO3 leakage into water resources. Inherent soil characteristics and management practices contributing to nonpoint NO3 loss from Midwestern soils, the impact of …

Fluid Fertilizer’S Role In Sustaining Soils Used For Bio-Fuels Production, John L. Kovar, Douglas Karlen

Douglas L Karlen

The short- and long-term effects on soil nutrient cycling, physical properties, and biological activity of striving for higher grain yields and removing crop residues for bio-fuels production must be understood to provide more quantitative crop and soil management guidelines. This study focuses on potassium (K) and sulfur (S) requirements of corn (Zea mays L.) grown for bioenergy feedstock production. Our objectives for 2008 were to: i) evaluate the performance of several S fertilizers, including liquid ammonium thiosulfate (12-0-0-26S), as S sources for corn grown in Iowa, and ii) establish a comprehensive tillage, nutrient management, crop residue removal, and cover crop …

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, …

Drought Effects On Composition And Yield For Corn Stover, Mixed Grasses, And Miscanthus As Bioenergy Feedstocks, Rachel Emerson, Amber Hoover, Allison Ray, Jeffrey Lacey, Marnie Cortez, Courtney Payne, Douglas L. Karlen, Stuart J. Birrell, David A. Laird, Robert Kallenbach, Josh Egenolf, Matthew Sousek, Thomas Voigt

Douglas L Karlen

Drought conditions in 2012 were some of the most severe in recent history. The purpose of this study is to examine the impact of drought on quality, quantity, and theoretical ethanol yield (TEY) of three bioenergy feedstocks, corn stover, mixed grasses from Conservation Reserve Program lands, and Miscanthus ×giganteus. To assess drought effects on these feedstocks, samples from 2010 (minimal to no drought) and 2012 (severe drought) were compared from multiple locations in the US. In all feedstocks, drought significantly increased extractives and reduced structural sugars and lignin; subsequently, TEYs were reduced 10–15%. Biomass yields were significantly reduced …

Nitrogen Management Of Winter Triticale, Lance R. Gibson, Carasella Nance, Douglas L. Karlen

Douglas L Karlen

Triticale (trit-ah-kay-lee) is a close relative of wheat. When durum wheat is pollinated with rye pollen, the cross is used in a breeding program to produce stable, self-replicating varieties. Triticale yield, stress tolerance, and disease resistance are typically greater than similar traits found in wheat. Triticale does not currently possess the grain traits of bread wheat, so its greatest market potential is as animal feed.

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 …

Corn Grain, Stover Yield And Nutrient Removal Validations At Regional Partnership Sites, Douglas L. Karlen, Stuart J. Birrell, Jane M. F. Johnson, Shannon L. Osborne, Thomas E. Schumacher, Gary E. Varvel, Richard B. Ferguson, Jeff M. Novak, James R. Fredrick, John M. Baker, John A. Lamb, Paul R. Adler, Greg W. Roth, Emerson D. Nafziger

Douglas L Karlen

Corn (Zea mays L.) stover has been identified as a major feedstock for cellulosic bioenergy. This report summarizes grain and stover yield as well as N, P, and K removal at several Sun Grant Regional Partnership (SGRP) sites. National Agricultural Statistical Service (NASS) grain yields were used to assess the relevancy of plot-scale yields with county averages. Seasonal variation in weather patterns caused yields to differ substantially among sites and years. Nutrient removal estimates were significantly influenced by the sampling method (i.e. analysis of hand samples between physiologic maturity and grain harvest versus stover collected during the harvest operation). Based …

Effects Of Corn Crop Residue Grazing On Soil Physical Properties And Subsequent Soybean Production In A Corn-Soybean Crop Rotation (A Progress Report), Justin Clark, James R. Russell, Douglas Karlen, Darrell Busby, L. James Secor, Brian Peterson, Larry Pellack, Carroll Olsen, Shawn C. Shouse

Douglas L Karlen

The highest cost to beef cow-calf producers is the feeding of stored feeds in winter months. To lower feed costs, many producers will try to extend the grazing season into the winter. The primary resource for winter grazing in the Midwest is corn crop residues. On the average, corn crop residue grazing will reduce the amount of hay needed to maintain cows by approximately one-half ton per acre grazed over the winter. Although crop residue grazing is quite effective in reducing feed costs, some producers are concerned that corn residue grazing will have an adverse effect on soybean yields the …

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% …

Soil Fertility Paradigms Evaluated Through Collaboration On-Farm And On-Station, Derrick N. Exner, Kathleen Delate, Douglas Karlen

Douglas L Karlen

A “paradigm” is a way of interpreting and making sense of the world. As such, our views on soil fertility are coherent with our interpretation of the scientific process and science institutions, and perhaps our feeling about the place of agriculture in the larger scheme of things. In agriculture today, two contradictory approaches to soil fertility uneasily coexist – the cation ratio paradigm (CR) and that referred to as “sufficient level of available nutrients” (SLAN).

Fluid Fertilizer’S Role In Sustaining Soils Used For Bio-Energy Feedstock Production, John L. Kovar, Douglas L. Karlen

Douglas L Karlen

The use of corn (Zea mays L.) as a bio-energy feedstock has attracted the attention of many producers. Recently, the focus has shifted from grain-based to cellulose-based ethanol production. In addition to biological conversion of corn stover to ethanol, thermal conversion (pyrolysis) of stover is being explored. Regardless of post-harvest processing, the short- and long-term effects of both increasing grain yields and removing stover on soil nutrient cycling, physical properties, and biological activity must be understood to ensure that soil productivity and ecosystem services are maintained. Our objectives for 2010 were to evaluate: (i) the use of surface or …

Potential Economic, Environmental Benefits Of Narrow Strip Intercropping, Richard M. Cruse, Douglas Karlen, Kenneth J. Moore

Douglas L Karlen

Since its establishment in 1989, the Cropping Systems interdisciplinary research issue team has worked to develop a cropping system that is more environmentally sustainable than cur­ rent cropping approaches but just as favorable economically. The team's work to date has focused on the strip intercropping concept.

Corn Response To Late-Spring Nitrogen Management In The Walnut Creek Watershed, Douglas L. Karlen, Ana L. Dinnes, Dan B. Jaynes, Charles R. Hurburgh Jr., Cynthia A. Cambardella, Thomas S. Colvin, Glen R. Rippke

Douglas L Karlen

A 400-ha subbasin study within the Walnut Creek watershed near Ames, IA, confirmed that using late-spring soil nitrate nitrogen (NO₃–N) test (LSNT) fertilizer recommendations could significantly reduce NO₃–N loss in drainage water, but detailed crop response was not reported. Herein we summarize corn (Zea mays L.) response to the LSNT program when implemented across the Clarion–Nicollet–Webster soil association. The LSNT was used to determine the recommended N fertilizer rate that was applied uniformly across each field except on check strips where zero or nonlimiting (>220 kg N ha⁻¹) sidedress N was applied. …

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 …

Planting Date Effects On Wintertriticale Grain And Forage Yield, Lance R. Gibson, Aaron J. Schwarte, David N. Sundberg, Douglas L. Karlen

Douglas L Karlen

Triticale (trit-ah-kay-lee) is a close relative of wheat. When durum wheat is pollinated with rye pollen, the cross is used in a breeding program to produce these stable, self-replicating varieties. Triticale yield, stress tolerance, and disease resistance are typically greater than similar traits found in wheat. Triticale doesn’t currently possess the grain traits of bread wheat, so its greatest market potential is as animal feed.

Planting Date Effects On Winter Triticale Grain Yield, Lance R. Gibson, Aaron J. Schwarte, David N. Sundberg, Douglas L. Karlen

Douglas L Karlen

Triticale (trit-ah-kay-lee) is a close relative of wheat resulting from pollinating durum wheat with rye pollen and using the cross in a breeding program to produce stable, self-replicating varieties. Yield, stress tolerance, and disease resistance are typically greater in triticale than in wheat. Triticale doesn’t currently possess the grain traits of bread wheat, so its greatest market potential is as animal feed.

Fluid Fertilizer’S Role In Sustaining Soils Used For Bio-Fuels Production, John L. Kovar, Douglas L. Karlen

Douglas L Karlen

The short- and long-term effects on soil nutrient cycling, physical properties, and biological activity of striving for higher grain yields and removing crop residues for bio-fuels production must be understood to provide more quantitative crop and soil management guidelines. This study focuses primarily on potassium (K) and sulfur (S) response by corn (Zea mays L.) grown for bio-energy feedstock production. Our objectives for 2009 were to evaluate (i) the performance of several S fertilizers, including liquid ammonium thiosulfate (12-0-0-26S), for corn grown in Iowa, and (ii) the use of surface or subsurface bands of N-P-K-S fluid fertilizers to optimize positional …

Fluid Fertilizer’S Role In Sustaining Soils Used For Bio-Fuels Production, John L. Kovar, Douglas L. Karlen

Douglas L Karlen

Fast pyrolysis is optimized for production of bio-oil. Product yields are typically ~65% bio-oil, 20% biochar, 15% syngas.

Project Objective

To investigate N, P, K, and S dynamics in a comprehensive residue removal, tillage, and nutrient management study

Project Treatments

*Residue removal: 0, 50%, 90%

*Tillage: chisel plow, no-till

*Nutrient management: conventional (30K plants/A), high input (44K plants/A)

•Bio-char: 0, 4.32 tons/A, 8.25 tons/A

•Cover crops: annual, perennial

2009 Soil Test Levels

2009 Nutrient Management

Field Measurements

•Stand counts

•Whole-plant samples at V6

•Ear-leaf samples at mid-silk

•Grain yield and moisture

•Stover yield and moisture

•Grain and stover nutrient content

Soil Quality, Yield Stability And Economic Attributes Of Alternative Crop Rotations, Douglas L. Karlen, Cynthia A. Cambardella, Antonio P. Mallarino

Douglas L Karlen

Three long-term rotational crop studies in Iowa and one in Wisconsin were examined for conclusive evidence of rotational effects on soil quality. Long-term yield data also were evaluated to determine if there was a quantifiable relationship between soil quality and yield or yield stability.

Fluid Fertilizer’S Role In Sustaining Soils Used For Bio-Fuels Production, John L. Kovar, Douglas Karlen

Douglas L Karlen

Project Objectives: 1)To evaluate several S sources for corn grown on low organic matter soils2)To investigate nutrient dynamics in a comprehensive tillage, nutrient management, and residue removal study. Sulfur Response: Site Characteristics • Eroded side slopes • Loam/silt loam (Typic Haplaquolls) • Corn after soybean • N fertilizer applied at planting + spoke-whee UAN (155 lb N/A) • Corn (Fontanelle 4693 planted 5/6/08, 32K plants/A S Fertilizer Treatments Control 30 lb S/A; 13-33-0-15S; 2x3 30 lb S/A; 21-0-0-24S; 2x3 30 lb S/A; 12-0-0-26S; 2x0

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.