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Impacts Of Conventional And Diversified Rotation Systems On Crop Yields, Soil Functions And Environmental Quality: Stage Ii/Year 2, Matthew Z. Liebman, Michael J. Castellano, Ann M. Johanns Jan 2015

Impacts Of Conventional And Diversified Rotation Systems On Crop Yields, Soil Functions And Environmental Quality: Stage Ii/Year 2, Matthew Z. Liebman, Michael J. Castellano, Ann M. Johanns

Leopold Center Completed Grant Reports

Research continued at a long-term crop rotation testing site near Boone, Iowa. In this stage of the trial, attention was directed to estimating soil erosion with the RUSLE2 model, measuring soil nitrogen transformations and nitrogen uptake by corn, and assessing the farm economics of these more varied crop production scenarios using enterprise budgeting techniques.


Enhancing Botanical Composition, Wildlife Habitat And Carbon Sequestration Of Pastures In South Central Iowa Through Soil Disturbance By Mob Grazing Of Beef Cattle, James R. Russell, Harris J. Sellers, Stephen Barnhart, Daniel G. Morrical, Helga Offenburger Jan 2015

Enhancing Botanical Composition, Wildlife Habitat And Carbon Sequestration Of Pastures In South Central Iowa Through Soil Disturbance By Mob Grazing Of Beef Cattle, James R. Russell, Harris J. Sellers, Stephen Barnhart, Daniel G. Morrical, Helga Offenburger

Leopold Center Completed Grant Reports

As Iowa pastures continue to be dominated by cool-season grass species, strategic integration of a single mob-grazing event into pasture management offers a tool to simultaneously increase productivity of pastures and to improve grassland wildlife habitat through increased biodiversity. However, the success of the maneuver depends on climate, soil and landscape.


Understanding Microbial Contributions To Soil Aggregation And Organic Matter Accumulation, Kirsten S. Hofmockel, Elizabeth Marie Bach Jan 2015

Understanding Microbial Contributions To Soil Aggregation And Organic Matter Accumulation, Kirsten S. Hofmockel, Elizabeth Marie Bach

Leopold Center Completed Grant Reports

The goal of the project investigators was to characterize soil bacterial and fungal communities and the rates at which they break down specific plant-derived carbon (C) molecules within soil aggregates in three farming systems.


Investigation Of Bacteria Transport And Resistance Mechanisms And Implications For Water Quality From Confinement Swine And Beef Grazing Production Systems In Iowa, Michelle Soupir, Matt Helmers, Michael L. Thompson, Laura R. Jarboe, Antonio P. Mallarino, Ramesh S. Kanwar Jan 2015

Investigation Of Bacteria Transport And Resistance Mechanisms And Implications For Water Quality From Confinement Swine And Beef Grazing Production Systems In Iowa, Michelle Soupir, Matt Helmers, Michael L. Thompson, Laura R. Jarboe, Antonio P. Mallarino, Ramesh S. Kanwar

Leopold Center Completed Grant Reports

This multi-scale, multi-year study was conducted to begin answering questions related to the fate and transport of nutrients and bacteria from land receiving manure application. Experiments were conducted on tile water drainage at an ISU Research Farm in northeast Iowa.


Soil Health And Productivity In Riparian Grass Buffers: A Re-Evaluation After 13 Years, James W. Raich, Richard Schulz Jan 2015

Soil Health And Productivity In Riparian Grass Buffers: A Re-Evaluation After 13 Years, James W. Raich, Richard Schulz

Leopold Center Completed Grant Reports

In 2001, soil health and productivity were surveyed in riparian grassland buffers adjacent to Bear Creek in northern Story County, Iowa. The investigators resampled these 24 plots in 2014 using the same techniques to see what changes had resulted from the conservation practices applied in the intervening years.


Suitability Of Winter Canola (Brassica Napus) For Enhancing Summer Annual Crop Rotations In Iowa, Mary H. Wiedenhoeft, Rafael A. Martinez-Feria, Thomas C. Kaspar, Keri L. Jacobs Jan 2015

Suitability Of Winter Canola (Brassica Napus) For Enhancing Summer Annual Crop Rotations In Iowa, Mary H. Wiedenhoeft, Rafael A. Martinez-Feria, Thomas C. Kaspar, Keri L. Jacobs

Leopold Center Completed Grant Reports

What are the prospects for winter canola as an alternative crop for Iowa farmers? This project examined the economics and costs/benefits of adding canola as a third crop or a cover crop in rotations.


Linking Soil And Water Quality With Crop Performance Across A Continuum Of Tillage And Management Strategies: Enhancing Sustainability Through Soil-Health-Promoting Practices, Kathleen Delate, Cynthia A. Cambardella, Matt Bakker, Ann M. Johanns Jan 2015

Linking Soil And Water Quality With Crop Performance Across A Continuum Of Tillage And Management Strategies: Enhancing Sustainability Through Soil-Health-Promoting Practices, Kathleen Delate, Cynthia A. Cambardella, Matt Bakker, Ann M. Johanns

Leopold Center Completed Grant Reports

Comparisons across the three Iowa research sites, with histories ranging from three to 17 years, allowed the research team to examine of the effects of crop rotation history (short vs. longer) and system (organic vs. conventional) on weed management, crop productivity, soil quality and soil microbial communities.


Understanding Soil Organic Matter Change: Modeling Root And Soil Interactions Across Agricultural Landscapes, Cynthia A. Cambardella, Todd A. Ontl, Lisa A. Schulte Moore, Randall K. Kolka Jan 2014

Understanding Soil Organic Matter Change: Modeling Root And Soil Interactions Across Agricultural Landscapes, Cynthia A. Cambardella, Todd A. Ontl, Lisa A. Schulte Moore, Randall K. Kolka

Leopold Center Completed Grant Reports

What are some options for enhancing organic content and carbon storage in soils that have been used in intensive row-crop production? The project looked at bioenergy feedstocks and how they might be employed to improve soil properties.


Crop Availability Of Phosphorus In Beef Manure, Antonio P. Mallarino, Mazhar Ul Haq, Nicolas Dagna Jan 2014

Crop Availability Of Phosphorus In Beef Manure, Antonio P. Mallarino, Mazhar Ul Haq, Nicolas Dagna

Leopold Center Completed Grant Reports

This study provided the first Iowa assessment of the availability of beef cattle manure phosphorus (P) for crops since the early 1970s.


Transitioning To Ecologically Functional Production Systems, Kirsten S. Hofmockel, Lisa A. Schulte Moore, Thomas M. Isenhart, Randall K. Kolka Jan 2014

Transitioning To Ecologically Functional Production Systems, Kirsten S. Hofmockel, Lisa A. Schulte Moore, Thomas M. Isenhart, Randall K. Kolka

Leopold Center Completed Grant Reports

A gap in transitioning to ecologically beneficial farming practices is the lack of understanding of how soils store carbon (C) and nitrogen (N)long term. Farmers need management practices for improving soil quality, increasing both belowground (live roots) and aboveground (live cover) biomass, increasing soil organic matter, and reducing greenhouse gas emissions. This project quantified root productivity, root decomposition, soil microbial dynamics, soil aggregation, and belowground C allocation in annual and perennial biomass cropping systems across multiple landscape positions.


Column Study To Access Bioretention Cell Filter Mixtures For Urban Stormwater Management, Sally D. Logsdon, Pat Sauer Jan 2014

Column Study To Access Bioretention Cell Filter Mixtures For Urban Stormwater Management, Sally D. Logsdon, Pat Sauer

Leopold Center Completed Grant Reports

The study examined several options for material mixtures in bioretention cells to keep water cleaner and cut down on pollution into urban storm sewers.


Improving Soil Quality By Conserving Insect Pathogens, Aaron J. Gassmann, Erin W. Hodgson, Eric H. Clifton Jan 2013

Improving Soil Quality By Conserving Insect Pathogens, Aaron J. Gassmann, Erin W. Hodgson, Eric H. Clifton

Leopold Center Completed Grant Reports

This study found that organic fields had a greater abundance of naturally occurring entomopathogenic fungi (EPF) than conventional fields in 2011, but that no differences were present in 2012. Conventional producers who used organic fertilizers on their fields had greater abundance of one type of EPF, Metarhizium, in their farm soils than other conventional producers. This suggests that organic practices in corn and soybean fields, and the application of organic fertilizers in conventional fields, could bolster the abundance of naturally occurring EPF.


Impacts Of Conventional And Diversified Rotation Systems On Crop Yields, Profitability, Soil Functions And Environmental Quality, Matthew Z. Liebman, Craig Chase, Michelle Wander, Mark D. Tomer Jan 2013

Impacts Of Conventional And Diversified Rotation Systems On Crop Yields, Profitability, Soil Functions And Environmental Quality, Matthew Z. Liebman, Craig Chase, Michelle Wander, Mark D. Tomer

Leopold Center Completed Grant Reports

Comparisons were made among contrasting cropping systems within a long-term, large-scale field experiment in Boone County, Iowa. Combining crop diversity with lower herbicide inputs and non-transgenic crops was effective in reducing requirements for nitrogen fertilizer; maintaining or improving weed suppression, grain yields, and profi ts; and increasing several soil quality indicators.


Exploring The Role Of Multifunctional Agriculture On The Future Of Agriculture And Rural Development, Thanos N. Papanicolaou, Kenneth M. Wacha, Christopher Wilson Jan 2013

Exploring The Role Of Multifunctional Agriculture On The Future Of Agriculture And Rural Development, Thanos N. Papanicolaou, Kenneth M. Wacha, Christopher Wilson

Leopold Center Completed Grant Reports

The goal of this project was better understanding of the interplay between climate shifts and management practices as it affects soil organic matter (SOM) stocks in agricultural fields. Two advanced computer models were used to study this issue. [Keywords: WEPP, CENTURY, CARBON, EROSION]


Use Of Mob Grazing To Improve Cattle Production, Enhance Legume Establishment And Increase Carbon Sequestration In Iowa Pastures, James R. Russell, Stephen K. Barnhart, Daniel G. Morrical, Harris J. Sellers Jan 2013

Use Of Mob Grazing To Improve Cattle Production, Enhance Legume Establishment And Increase Carbon Sequestration In Iowa Pastures, James R. Russell, Stephen K. Barnhart, Daniel G. Morrical, Harris J. Sellers

Leopold Center Completed Grant Reports

Mob grazing is a variation on rotational grazing that has been proposed to have promise as one of the tactics graziers can use to improve cattle performance and environmental quality. This project looked at whether and how mob grazing could benefit livestock and producer management of their pastures and soil resources.


Increasing Carbon Sequestration Of Working Prairie By Reducing Invasive Species In A Fire And Grazing System, Ryan Harr, David M. Engle, Devan A. Mcgranahan, Jessica J. Veenstra, Aaron Lee Daigh Jan 2012

Increasing Carbon Sequestration Of Working Prairie By Reducing Invasive Species In A Fire And Grazing System, Ryan Harr, David M. Engle, Devan A. Mcgranahan, Jessica J. Veenstra, Aaron Lee Daigh

Leopold Center Completed Grant Reports

The investigators looked at one method for curbing invasive species that limit carbon sequestration potential for tallgrass prairie stands. They also learned that grasslands dominated by either warm-season, cool-season, or mixed stands are likely equal in their carbon sequestration potential.


Soil Moisture Dynamics And Plant Transpiration Under Contrasting Annual-Perennial Cover Types, Matt Helmers, Heidi Asbjornsen, Amy L. Kaleita Jan 2012

Soil Moisture Dynamics And Plant Transpiration Under Contrasting Annual-Perennial Cover Types, Matt Helmers, Heidi Asbjornsen, Amy L. Kaleita

Leopold Center Completed Grant Reports

Soil moisture dynamics are influenced by land cover, thus different land covers would be expected to have different soil moisture behavior. This project tested various land covers and crops to see whether and how moisture was retained or depleted.


Conversion To Perennial Vegetation: Quantifying Soil Water Regime, Aeration, And Implications For Enhancing Soil Resilience To Climate Change, Robert Horton Jr., Thomas J. Sauer, Aaron Lee Daigh Jan 2012

Conversion To Perennial Vegetation: Quantifying Soil Water Regime, Aeration, And Implications For Enhancing Soil Resilience To Climate Change, Robert Horton Jr., Thomas J. Sauer, Aaron Lee Daigh

Leopold Center Completed Grant Reports

Iowa was once awash with native prairie vegetation, and now it is covered with annual crops. This project looked at the different effects these two systems have on Iowa's landscape and natural resource base.


The Impact Of Biodiversity Services In Row Crop Production In Annual Verses Perennial Landscapes, Matthew E. O'Neal, Lisa A. Schulte Moore Jan 2011

The Impact Of Biodiversity Services In Row Crop Production In Annual Verses Perennial Landscapes, Matthew E. O'Neal, Lisa A. Schulte Moore

Leopold Center Completed Grant Reports

Researchers studied the behavior of soybean aphids in fields and prairies, and the implications for biological control of these pests


Integrated Soil And Weed Management Production Systems For Perennial Food Crops, Gail R. Nonnecke, Craig A. Dilley, Thomas E. Loynachan Jan 2010

Integrated Soil And Weed Management Production Systems For Perennial Food Crops, Gail R. Nonnecke, Craig A. Dilley, Thomas E. Loynachan

Leopold Center Completed Grant Reports

Several alternative weed management tactics for strawberry and grape production were tested for their effects on weed control, crop yield and soil quality enhancement.


The Role Of Herbaceous Woodland Perennial Diversity For Improving Nutrient Uptake Of Riparian Areas, Jan R. Thompson, Catherine Mabry Mcmullen Jan 2009

The Role Of Herbaceous Woodland Perennial Diversity For Improving Nutrient Uptake Of Riparian Areas, Jan R. Thompson, Catherine Mabry Mcmullen

Leopold Center Completed Grant Reports

Investigation of disturbed and intact woodlands herbaceous understories provided information on species present, biomass production and nutrient capture in preserved and secondary forests.


Assessing Soil Quality Impacts After Conversion Of Marginal Cropland To Productive Conservation, Thomas J. Sauer, David E. James, Cynthia A. Cambardella Jan 2009

Assessing Soil Quality Impacts After Conversion Of Marginal Cropland To Productive Conservation, Thomas J. Sauer, David E. James, Cynthia A. Cambardella

Leopold Center Completed Grant Reports

Planting trees on poor quality cropland may yield some benefits for increasing soil organic carbon. Test plots in four parts of Iowa were examined to determine the level of benefits possible to achieve.


Establishment Of A Field School For Weed Ecology And Management, Matthew Z. Liebman, Robert G. Hartzler Jan 2009

Establishment Of A Field School For Weed Ecology And Management, Matthew Z. Liebman, Robert G. Hartzler

Leopold Center Completed Grant Reports

Multiyear field experiments using three crop rotations, two of which were low-external-input (LEI) systems, showed that cropping systems can be designed to achieve large reductions in agrichemical use while providing effective weed control and high yields and profits.


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 Jan 2004

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

Leopold Center Completed Grant Reports

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.


Soil Amendment Effects Of Crop-Weed Interactions, Matthew Z. Liebman, Thomas L. Richard Jan 2003

Soil Amendment Effects Of Crop-Weed Interactions, Matthew Z. Liebman, Thomas L. Richard

Leopold Center Completed Grant Reports

The used bedding from hooped hog production structures can be composted and spread on farm fields as a soil amendment. Researchers studied how this composted material affects crop yields, weed growth, and soil components.


Eastern Gamagrass Seed Dormancy, Allen D. Knapp, Charles Brummer, Kenneth J. Moore Jan 2000

Eastern Gamagrass Seed Dormancy, Allen D. Knapp, Charles Brummer, Kenneth J. Moore

Leopold Center Completed Grant Reports

Eastern gamagrass has considerable value as a forage source and conservation aid, but can be very difficult to establish because its seed does not germinate easily, even with all the necessary environmental factors present. Understanding seed dormancy in eastern gamagrass is the major objective of this work.


Calibration Of The Late-Spring Soil Nitrate Test For Manured Soils, Alfred M. Blackmer Jan 1996

Calibration Of The Late-Spring Soil Nitrate Test For Manured Soils, Alfred M. Blackmer

Leopold Center Completed Grant Reports

In the past, farmers have generally assumed that nitrogen fertilizers were needed on manured cornfields and questioned the value of using the late-spring soil nitrate test. In this project, Iowa farmers cooperated in studies at 111 sites to calibrate the test on manured cornfields. The value of animal manures as a nitrogen fertilizer for corn, and the possible benefits to corn producers, were also assessed. Results show that guidelines for using the late-spring test in manured cornfields need to be revised to decrease amounts of fertilizer nitrogen recommended. Widespread implementation of the late-spring soil nitrate test and the end-of-season cornstalk ...


High-Intensity, Year-Round Rotational Grazing, James R. Russell Jan 1995

High-Intensity, Year-Round Rotational Grazing, James R. Russell

Leopold Center Completed Grant Reports

Compared to row crops, most forage crops reduce water runoff, therefore limiting soil erosion. Forage systems also require less chemical pest control than row crops. Because legume forage species fix nitrogen in the soil, they seldom require nitrogen fertilization. Despite these advantages, profitability limitations have kept forage use from expanding.


Interactions Of Vam Fungi, Pesticides And Crops, Thomas B. Moorman, K. Jayachandran Jan 1995

Interactions Of Vam Fungi, Pesticides And Crops, Thomas B. Moorman, K. Jayachandran

Leopold Center Completed Grant Reports

V esicular arbuscular mycorrhizal fungi (V AM) are beneficial root symbionts of most crops, including corn and soybeans. These fungi colonize plant roots, facilitating nutrient ex­ change between the plant and the fungus. The plant supplies carbon for fungal growth; in turn, the VAM enhances uptake of relatively immobile nutrients such as phosphorus (P). The network of external fungal filaments, or hyphae (see photos below), extends outside the root up to several centimeters in the soil, allowing the fungus access to soil P otherwise unavailable to the plant.


Control Of Soil-Borne Pathogens With Strategic Use Of Animal Manures, Charlie A. Martinson Jan 1995

Control Of Soil-Borne Pathogens With Strategic Use Of Animal Manures, Charlie A. Martinson

Leopold Center Completed Grant Reports

Root-infecting fungi cause significant damage to soybeans and corn. Fusarium graminearum is a major stalk rot pathogen of corn. Helminthosporiumpedicellatum, a native soil­ borne fungus, causes root rot of corn. Neither of these fungi is controlled well by plant breed­ ing for resistance or crop rotation. Brown stem rot caused by Phialophora gregata is the most important disease of soybean in Iowa. Again, resistance is not completely successful, and rotation of at least four years to another crop is needed to obtain satisfactory control.