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Articles 1 - 30 of 78
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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. …
Impact Of Biochar Amendments On The Quality Of A Typical Midwestern Agricultural Soil, David A. Laird, Pierce Fleming, Dedrick D. Davis, Robert Horton, Baiqun Wang, Douglas L. Karlen
Impact Of Biochar Amendments On The Quality Of A Typical Midwestern Agricultural Soil, David A. Laird, Pierce Fleming, Dedrick D. Davis, Robert Horton, Baiqun Wang, Douglas L. Karlen
Douglas L Karlen
Biochar, a co-product of thermochemical conversion of lignocellulosic materials into advanced biofuels, may be used as a soil amendment to enhance the sustainability of biomass harvesting. We investigated the impact of biochar amendments (0, 5, 10, and 20 g-biochar kg− 1 soil) on the quality of a Clarion soil (Mesic Typic Hapludolls), collected (0–15 cm) in Boone County, Iowa. Repacked soil columns were incubated for 500 days at 25 °C and 80% relative humidity. On week 12, 5 g of dried and ground swine manure was incorporated into the upper 3 cm of soil for half of the columns. Once …
Crop Rotation Effects On N03-N Leaching And Corn Yields Under Manure Management Practices, R. S. Kanwar, D. L. Karlen, C. A. Cambardella, C. Pederson
Crop Rotation Effects On N03-N Leaching And Corn Yields Under Manure Management Practices, R. S. Kanwar, D. L. Karlen, C. A. Cambardella, C. Pederson
Douglas L Karlen
Nonpoint source nutrient pollution is recognized as an important environmental and social issue for several reasons. First, manure from swine production facilities can have serious impacts on the quality of surface and ground water resources. Second, several states are in the process of creating laws to reduce nitrogen and phosphorus loadings from manure to soil and water resources. Third, pollution of water resources from nutrients supplied by manure to croplands will set parameters for developing public policies on the management of manure.
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
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 …
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). …
An Evaluation Of Soil Survey Crop Yield Interpretations For Two Central Iowa Farms, A. L. Steinwand, D. L. Karlen, T. E. Fenton
An Evaluation Of Soil Survey Crop Yield Interpretations For Two Central Iowa Farms, A. L. Steinwand, D. L. Karlen, T. E. Fenton
Douglas L Karlen
This study was conducted on four adjacent 16-ha (40-ac) fields within the Clarion-Nicollet-Webster soil association to (1) determine if crop yield interpretations derived from 1:15840 soil survey maps could be used for developing field-scale management plans: and (2) to determine if soils in adjacent fields were derived using a computer-based Soil Information System (SIS) and compared with measured yields. Soil map units in all four fields were taxonomically variable, but this did not affect expected crop yields. Average expected and measured corn and soybean yields agreed within 9 and 12% for conentional management at the field-scale. We conclude that yield …
An Evaluation Of Soil Survey Crop Yield Interpretations For Two Central Iowa Farms, A. L. Steinwand, D. L. Karlen, T. E. Fenton
An Evaluation Of Soil Survey Crop Yield Interpretations For Two Central Iowa Farms, A. L. Steinwand, D. L. Karlen, T. E. Fenton
Douglas L Karlen
This study was conducted on four adjacent 16-ha (40-ac) fields within the Clarion-Nicollet-Webster soil association to (1) determine if crop yield interpretations derived from 1:15840 soil survey maps could be used for developing field-scale management plans: and (2) to determine if soils in adjacent fields were derived using a computer-based Soil Information System (SIS) and compared with measured yields. Soil map units in all four fields were taxonomically variable, but this did not affect expected crop yields. Average expected and measured corn and soybean yields agreed within 9 and 12% for conentional management at the field-scale. We conclude that yield …
Biochar Impact On Nutrient Leaching From A Midwestern Agricultural Soil, David Laird, Pierce Flemming, Baiqun Wang, Robert Horton, Douglas Karlen
Biochar Impact On Nutrient Leaching From A Midwestern Agricultural Soil, David Laird, Pierce Flemming, Baiqun Wang, Robert Horton, Douglas Karlen
Douglas L Karlen
Application of biochar to highly weathered tropical soils has been shown to enhance soil quality and decrease leaching of nutrients. Little, however, is known about the effects of biochar applications on temperate region soils. Our objective was to quantify the impact of biochar on leaching of plant nutrients following application of swine manure to a typical Midwestern agricultural soil. Repacked soil columns containing 0, 5, 10, and 20 g-biochar kg− 1-soil, with and without 5 g kg− 1 of dried swine manure were leached weekly for 45 weeks. Measurements showed a significant decrease in the total amount of N, P, …
Soil Quality: A Review Of The Science And Experiences In The Usa, B. J. Wienhold, S. S. Andrews, D. L. Karlen
Soil Quality: A Review Of The Science And Experiences In The Usa, B. J. Wienhold, S. S. Andrews, D. L. Karlen
Douglas L Karlen
An increasing human population is placing greater demand on soil resources, and as a result degradation is taking place in many regions of the world. This is critical because soils perform a number of essential processes including supporting food and fiber production, influencing air quality through interaction with the atmosphere, and serving as a medium for storage and purification of water. The soil quality concept was introduced to complement soil science research by making our understanding of soils more complete and helping guide the use and allocation of labor, energy, fiscal, and other inputs as agriculture intensifies and expands to …
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 …
Soil Quality: A Review Of The Science And Experiences In The Usa, Brian J. Wienhold, S.S. Andrews, D.L. Karlen
Soil Quality: A Review Of The Science And Experiences In The Usa, Brian J. Wienhold, S.S. Andrews, D.L. Karlen
Douglas L Karlen
An increasing human population is placing greater demand on soil resources, and as a result degradation is taking place in many regions of the world. This is critical because soils perform a number of essential processes including supporting food and fiber production, influencing air quality through interaction with the atmosphere, and serving as a medium for storage and purification of water. The soil quality concept was introduced to complement soil science research by making our understanding of soils more complete and helping guide the use and allocation of labor, energy, fiscal, and other inputs as agriculture intensifies and expands to …
Recent Advances In Soil Quality Assessment In The United States, Brian J. Wienhold, S.S. Andrews, H. Kuykendall, D.L. Karlen
Recent Advances In Soil Quality Assessment In The United States, Brian J. Wienhold, S.S. Andrews, H. Kuykendall, D.L. Karlen
Douglas L Karlen
Soil quality is a concept that is useful as an educational and assessment tool. A number of assessment tools have been developed including: the Soil Conditioning Index (SCI), the Soil Management Assessment Framework (SMAF), the AgroEcosystem Performance Assessment Tool (AEPAT), and the new Cornell “Soil Health Assessment”. The SMAF and AEPAT were developed as malleable tools for assessing soil response to management. The Cornell Assessment builds on the SMAF approach to score laboratory tests in terms of soil function. This paper updates efforts to improve availability and utility, implementation, and future research goals associated with the SMAF. Additional scoring curves …
Evaluation Of Β-Glucosidase Activity As A Soil Quality Indicator For The Soil Management Assessment Framework, D. E. Stott, S. S. Andrews, M. A. Liebig, Brian J. Wienhold, D. L. Karlen
Evaluation Of Β-Glucosidase Activity As A Soil Quality Indicator For The Soil Management Assessment Framework, D. E. Stott, S. S. Andrews, M. A. Liebig, Brian J. Wienhold, D. L. Karlen
Douglas L Karlen
The Soil Management Assessment Framework (SMAF) was developed to assess conservation effects on soil, and uses multiple soil quality indicator measurements to compare soil functioning. Our objective was to develop a SMAF compatible scoring equation for soil β-glucosidase (BG) activity using published data sets representing different soils and management. The resulting equation was an S-shaped curve: y = a/[1 + bexp(−cx)], where x is the measured BG activity (mg p-nitrophenol [PNP] released kg−1 soil h−1), a and b are constants, and c is a factor modified by soil classification, texture, and climate. Data from a study conducted near Mandan, ND …
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
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 …
Comparison Of Two Soil Quality Indexes To Evaluate Cropping Systems In Northern Colorado, T.M. Zobeck, A.D. Halvorson, Brian J. Wienhold, V. Acosta-Martinez, D.L. Karlen
Comparison Of Two Soil Quality Indexes To Evaluate Cropping Systems In Northern Colorado, T.M. Zobeck, A.D. Halvorson, Brian J. Wienhold, V. Acosta-Martinez, D.L. Karlen
Douglas L Karlen
Various soil management or quality assessment tools have been proposed to evaluate the effects of land management practices on soil, air, and water resources. Two of them are the Soil Management Assessment Framework and the Soil Conditioning Index (SCI). This study was conducted to test the hypothesis that the Soil Quality Index (SQI) estimated by the Soil Management Assessment Framework can detect more minute changes in soil management than SCI and to test SCI response to other soil quality (SQ) indicators. These SQ indexes were tested on irrigated cropping systems near Fort Collins, Colorado, that included no-till and conventionally-tilled corn …
Protocol For Indicator Scoring In The Soil Management Assessment Framework (Smaf), Brian J. Wienhold, D.L. Karlen, S.S. Andrews, D.E. Stott
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. …
N-Management And Crop Rotation Effects On Yield And Residual Soil Nitrate Levels, A. Bakhsh, R. S. Kanwar, D. L. Karlen, C. A. Cambardella, T. B. Bailey, T. B. Moorman, T. S. Colvin
N-Management And Crop Rotation Effects On Yield And Residual Soil Nitrate Levels, A. Bakhsh, R. S. Kanwar, D. L. Karlen, C. A. Cambardella, T. B. Bailey, T. B. Moorman, T. S. Colvin
Douglas L Karlen
Swine production facilities are becoming more concentrated in Iowa, and public is concerned about the impact of using swine manure for crop production on soil and water quality. This field study was conducted from 1996 to 1998 to compare the effects of liquid swine manure and urea ammonium nitrate (UAN) application on crop yield and residual soil nitrate for continuous corn (Zea mays L.) and corn-soybean (Glycine max (L.) Merr.) rotation systems. Six N management treatments were replicated three times in a randomized complete block design at Iowa State University's northeastern research center in Nashua, Iowa. Injected UAN provided 135 …
Crop Residues: The Rest Of The Story, Douglas L. Karlen, Rattan Lal, Ronald F. Follett, John M. Kimble, Jerry L. Hatfield, John A. Miranowski, Cynthia A. Cambardella, Andrew Manale, Robert P. Anex, Charles W. Rice
Crop Residues: The Rest Of The Story, Douglas L. Karlen, Rattan Lal, Ronald F. Follett, John M. Kimble, Jerry L. Hatfield, John A. Miranowski, Cynthia A. Cambardella, Andrew Manale, Robert P. Anex, Charles W. Rice
Douglas L Karlen
Synopsis In the February 15, 2009 issue of ES&T Strand and Benford argued that oceanic deposition of agricultural crop residues was a viable option for net carbon sequestration (43 [4], 1000−1007). In reviewing the calculations and bringing their experience to bear, Karlen et al. argue in this Viewpoint that crop residue oceanic permanent sequestration (CROPS) as envisioned by Strand and Benford will not work. They further propose alternative possibilities in agricultural methods to achieve a net decrease of CO2 emissions.
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
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
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 …
Crop Residue Harvest Economics: An Iowa And North Dakota Case Study, David W. Archer, Douglas L. Karlen, Mark A. Liebig
Crop Residue Harvest Economics: An Iowa And North Dakota Case Study, David W. Archer, Douglas L. Karlen, Mark A. Liebig
Douglas L Karlen
Rigorous economic analyses are crucial for the successful launch of lignocellulosic bioenergy facilities in 2014 and beyond. Our objectives are to (1) introduce readers to a query tool developed to use data downloaded from the Agricultural Research Service (ARS) REAPnet for constructing enterprise budgets and (2) demonstrate the use of the query tool with REAPnet data from two field research sites (Ames, IA, and Mandan, ND) for evaluating short-term economic performance of various biofuel feedstock production strategies. Our results for both sites showed that short-term (<3 years) impacts on grain profitability were lower at lower average annual crop residue removal rates. However, it will be important to monitor longer term changes to see if grain profitability declines over time and if biomass harvest degrades soil resources. Analyses for Iowa showed short-term breakeven field-edge biomass prices of $26–$42Mg−1 among the most efficient strategies, while results for North Dakota showed breakeven prices …
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, W. W. Wilhelm
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, W. W. 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 grain …
Challenges Of Managing Liquid Swine Manure, Douglas Karlen, Cynthia A. Cambardella, Rameshwar S. Kanwar
Challenges Of Managing Liquid Swine Manure, Douglas Karlen, Cynthia A. Cambardella, Rameshwar S. Kanwar
Douglas L Karlen
Liquid swine manure can be a resource for providing essential plant nutrients and building soil resources, but its management for maximum productivity with minimum environmental impact is often very difficult. Failure to understand the challenges may result in expectations or even regulations that are impossible to achieve. Our objective is to provide producers and policy makers with information regarding agronomic and environmental challenges of liquid swine manure management based on results from a 6-year study with continuous corn (Zea mays L.) and a corn-soybean [Glycine max (L.) Merr.] rotation in Iowa. Challenges that we encountered are openly discussed to increase …
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, …
Crop Residues, Douglas L. Karlen, David R. Huggins
Crop Residues, Douglas L. Karlen, David R. Huggins
Douglas L Karlen
Crop residues (e.g., corn stover and small grain straw) are sometimes excluded when discussing cellulosic energy crops per se, but because of the vast area upon which they are grown and their current role in the development of cellulosic energy systems, this chapter will review several important attributes of this “herbaceous” feedstock. Crop residues are potential feedstock sources for second-generation biofuel production. These materials, along with dedicated energy crops (e.g., switchgrass [Panicum virgatum L.], Miscanthus [Miscanthus × giganteus]), are considered to have greater potential for biofuel production than current first-generation feedstock (i.e., corn grain) [1–3]. Production of ethanol and other …
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
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 …
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, Jim Russell, Douglas Karlen, Darrell Busby, L. James Secor, Brian Peterson, Larry Pellack, Carroll Olsen, Shawn Shouse
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, Jim Russell, Douglas Karlen, Darrell Busby, L. James Secor, Brian Peterson, Larry Pellack, Carroll Olsen, Shawn Shouse
Douglas L Karlen
Beginning in 1999, two locations in Iowa (Chariton, Atlantic) were used to study the effects of corn residue grazing by beef cows on soil characteristics and soybean yields the following growing season. Cows were allowed to graze inside selected paddocks at monthly periods throughout the fall and winter. For a grazed and ungrazed comparison, grazing exclosures were used inside the grazed paddocks while one paddock was left ungrazed for a control. The use of this design was to determine if grazing had any adverse effects on soil characteristics and at what date and weather conditions did they occur. Also equal …
Nitrogen Management Of Winter Triticale, Lance R. Gibson, Carasella Nance, Douglas L. Karlen
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.
Soil Management Implications Of Producing Biofuel Feedstock, Jane M. F. Johnson, David W. Archer, Douglas L. Karlen, Sharon L. Weyers, Wally W. Wilhelm
Soil Management Implications Of Producing Biofuel Feedstock, Jane M. F. Johnson, David W. Archer, Douglas L. Karlen, Sharon L. Weyers, Wally W. Wilhelm
Douglas L Karlen
The use of plant biomass for energy has existed since humans mastered the use of fire, although utilization beyond the open fire has evolved. The concept of using recent biomass as a major energy feedstock is being revisited, driven by high consumer demand (growing population), declining domestic oil supplies, increasing cost of fossil fuels, and a desire to curb the emission of greenhouse gases (Johnson et al., 2007b). In general terms, agriculture and forestry are the economic sectors commercially producing a wide array of bioenergy feedstocks (e.g., grains, herbaceous annuals, herbaceous perennials, and woody perennials). For this review, biomass feedstock …