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Environmental Sciences

2014

Iowa State University

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Articles 1 - 30 of 116

Full-Text Articles in Life Sciences

Nutrient Reduction Strategy Update And Opportunities For Agribusinesses, Jamie Benning Dec 2014

Nutrient Reduction Strategy Update And Opportunities For Agribusinesses, Jamie Benning

Proceedings of the Integrated Crop Management Conference

The Iowa Nutrient Reduction Strategy is a science-based framework that identifies in-field, edge of field, and land use practices that minimize loss of nitrogen and phosphorus to surface water. In addition to reductions in agricultural non-point sources of nutrients, the strategy also identifies reductions for non-agricultural point sources such as municipal wastewater treatment plants. The Hypoxia Task Force identified a goal of reducing the total nitrogen and total phosphorus load by 45%. The Iowa Nutrient Reduction Strategy outlines the effectiveness of the identified agricultural practices to assist farmers in selecting practices individually or in combination to meet their nutrient reduction ...


Fire Induced Reproductive Mechanisms Of A Symphoricarpos (Caprifoliaceae) Shrub After Dormant Season Burning, John Derek Scasta, David M. Engle, Ryan N. Harr, Diane M. Debinski Dec 2014

Fire Induced Reproductive Mechanisms Of A Symphoricarpos (Caprifoliaceae) Shrub After Dormant Season Burning, John Derek Scasta, David M. Engle, Ryan N. Harr, Diane M. Debinski

Ecology, Evolution and Organismal Biology Publications

Background: Symphoricarpos, a genus of the Caprifoliaceae family, consists of about 15 species of clonal deciduous shrubs in North America and 1 species endemic to China. In North American tallgrass prairie, Symphoricarpos orbiculatus (buckbrush) is the dominant shrub often forming large colonies via sexual and asexual reproductive mechanisms. Symphoricarpos shrubs, in particular S. orbiculatus, use a unique sexual reproductive mechanism known as layering where vertical stems droop and the tips root upon contact with the soil. Because of conflicting societal values of S. orbiculatus for conservation and agriculture and the current attempt to restore historical fire regimes, there is a ...


Comparison Of Cellulosic Ethanol Yields From Midwestern Maize And Reconstructed Tallgrass Prairie Systems Managed For Bioenergy, V. A. Nichols, F. E. Miguez, M. E. Jarchow, M. Z. Liebman, B. S. Dien Dec 2014

Comparison Of Cellulosic Ethanol Yields From Midwestern Maize And Reconstructed Tallgrass Prairie Systems Managed For Bioenergy, V. A. Nichols, F. E. Miguez, M. E. Jarchow, M. Z. Liebman, B. S. Dien

Agronomy Publications

Maize- and prairie-based systems were investigated as cellulosic feedstocks by conducting a 9 ha side-by-side comparison on fertile soils in the Midwestern United States. Maize was grown continuously with adequate fertilization over years both with and without a winter rye cover crop, and the 31-species reconstructed prairie was grown with and without spring nitrogen fertilization. Both maize stover and prairie biomass were harvested in the fall. We compared amounts of cellulosic biomass produced and harvested, carbohydrate contents as measured by both dietary and detergent methods, and estimated cellulosic ethanol yields per hectare. From 2009–2013, the cropping system with the ...


Reconstructing Vegetation Past: Pre-Euro-American Vegetation For The Midwest Driftless Area, Usa, Monika E. Shea, Lisa A. Schulte, Brian J. Palik Dec 2014

Reconstructing Vegetation Past: Pre-Euro-American Vegetation For The Midwest Driftless Area, Usa, Monika E. Shea, Lisa A. Schulte, Brian J. Palik

Natural Resource Ecology and Management Publications

Historical reference conditions provide important context for creating ecological restoration and management plans. The U.S. 19th Century Public Land Survey (PLS) records provide extensive ecological information for constructing such reference conditions. We used PLS records to reconstruct pre-Euro-American tree species cover class and vegetation structure types for the Midwest Driftless Area, a 55,000 km2 region currently experiencing multiple conservation threats. We related cover classes to soil texture, topographic roughness, and distance from waterway. Our analyses revealed that the landscape of the Driftless Area was mostly composed of savanna, with two large patches of closed forest and smaller, scattered ...


Satellite-Based Management Tool For Oak Savanna Ecosystem Restoration, Peter T. Wolter, Elizabeth A. Berkley, Scott D. Peckham, Aditya Singh Dec 2014

Satellite-Based Management Tool For Oak Savanna Ecosystem Restoration, Peter T. Wolter, Elizabeth A. Berkley, Scott D. Peckham, Aditya Singh

Natural Resource Ecology and Management Publications

The structure and function of oak Quercus spp. savanna ecosystems in the North American Midwest were originally maintained by an active disturbance regime (often fire). Subsequent reductions in the frequency of disturbance after European settlement have facilitated rapid, regional conversion of these ecosystems to more closed-canopy forest. Hence, regional-scale management strategies are now needed to restore critical spatial gradients of light, temperature, soil moisture, and soil organic matter for recovery and sustenance of the unique mosaic of understory grass and forb species assemblages that define oak savannas. Tree species composition, distribution, mortality, basal area, and canopy cover are important forest ...


The North American Carbon Program Multi-Scale Synthesis And Terrestrial Model Intercomparison Project – Part 2: Environmental Driver Data, Y. Wei, S. Liu, D. N. Huntzinger, A. M. Michalak, N. Viovy, W. M. Post, C. R. Schwalm, K. Schaefer, A. R. Jacobson, Chaoqun (Crystal) Lu, Hanqin Tian, D. M. Ricciuto, R. B. Cook, J. Mao, X. Shi Dec 2014

The North American Carbon Program Multi-Scale Synthesis And Terrestrial Model Intercomparison Project – Part 2: Environmental Driver Data, Y. Wei, S. Liu, D. N. Huntzinger, A. M. Michalak, N. Viovy, W. M. Post, C. R. Schwalm, K. Schaefer, A. R. Jacobson, Chaoqun (Crystal) Lu, Hanqin Tian, D. M. Ricciuto, R. B. Cook, J. Mao, X. Shi

Chaoqun (Crystal) Lu

Ecosystems are important and dynamic components of the global carbon cycle, and terrestrial biospheric models (TBMs) are crucial tools in further understanding of how terrestrial carbon is stored and exchanged with the atmosphere across a variety of spatial and temporal scales. Improving TBM skills, and quantifying and reducing their estimation uncertainties, pose significant challenges. The Multi-scale Synthesis and Terrestrial Model Intercomparison Project (MsTMIP) is a formal multi-scale and multi-model intercomparison effort set up to tackle these challenges. The MsTMIP protocol prescribes standardized environmental driver data that are shared among model teams to facilitate model–model and model–observation comparisons. This ...


Reproductive Success Of The American Oystercatcher (Haematopus Palliatus) In Texas, Lianne M. Koczur, Alexandra E. Munters, Susan A. Heath, Bart M. Ballard, M. Clay Green, Stephen J. Dinsmore, Fidel Hernández Dec 2014

Reproductive Success Of The American Oystercatcher (Haematopus Palliatus) In Texas, Lianne M. Koczur, Alexandra E. Munters, Susan A. Heath, Bart M. Ballard, M. Clay Green, Stephen J. Dinsmore, Fidel Hernández

Natural Resource Ecology and Management Publications

The American Oystercatcher (Haematopus palliatus) is listed as a Species of High Concern in the United States Shorebird Conservation Plan due to a small population size and threats during its annual cycle. Previous studies of the American Oystercatcher have focused on Atlantic Coast populations; however, little is known about the reproductive success of the western Gulf Coast population. The objective of this study was to determine nest and brood survival of American Oystercatchers in Texas. A total of 337 nests and 121 broods were monitored on the Texas Gulf Coast during 2011–2013. The top model for nest survival in ...


Book Review Of Conservation By Proxy: Indicator, Umbrella, Keystone, Flagship, And Other Surrogate Species, Tyler J. Grant, Peter G. Eyheralde, Melissa S. C. Telemeco, Amy L. Moorhouse, Rebecca A. Reeves, Karin Grimlund, Amy Podaril, Sarah E. Emeterio, Robert W. Klaver Dec 2014

Book Review Of Conservation By Proxy: Indicator, Umbrella, Keystone, Flagship, And Other Surrogate Species, Tyler J. Grant, Peter G. Eyheralde, Melissa S. C. Telemeco, Amy L. Moorhouse, Rebecca A. Reeves, Karin Grimlund, Amy Podaril, Sarah E. Emeterio, Robert W. Klaver

Natural Resource Ecology and Management Publications

In the tallgrass prairies of the United States, the regal fritillary (Speyeria idalia) often is considered a reliable indicator of high quality remnant habitat. Purple milkweed (Asclepias purpurascens) is considered an indicator of high quality oak savanna habitat at the edge of prairie. Indicator and other surrogate species often are regarded as inescapable necessities in conservation, because limited budgets and the myriad pieces of an ecosystem render comprehensive monitoring impossible. Regardless of whether or not surrogate species are necessary, do they really work?


Assessing Cost-Effectiveness Of The Conservation Reserve Program And Its Interaction With Crop Insurance Subsidies, Ruiqing Miao, Hongli Feng, David A. Hennessy, Xiaodong Du Nov 2014

Assessing Cost-Effectiveness Of The Conservation Reserve Program And Its Interaction With Crop Insurance Subsidies, Ruiqing Miao, Hongli Feng, David A. Hennessy, Xiaodong Du

CARD Working Papers

Strong demand for agricultural commodities, high crop prices and pressure to reduce government budget deficits heighten the need for land retirement programs to be designed to maximize environmental benefits for any given budget outlay. The Conservation Reserve Program (CRP) is the largest land retirement program while the federal crop insurance program (FCIP) is the largest federal program supporting U.S. agriculture. We examine the environmental and budgetary implications of alternative CRP enrollment mechanisms in the context of the program’s interactions with FCIP. We demonstrate that the current CRP enrollment mechanism is inconsistent with cost-effective targeting. We also identify a ...


The Impact Of An Eu-Us Transatlantic Trade And Investment Partnership Agreement On Biofuel And Feedstock Markets, John C. Beghin, Jean-Christophe Bureau, Alexandre Gohin Nov 2014

The Impact Of An Eu-Us Transatlantic Trade And Investment Partnership Agreement On Biofuel And Feedstock Markets, John C. Beghin, Jean-Christophe Bureau, Alexandre Gohin

CARD Working Papers

We assess the impact of a potential TTIP bilateral free trade agreement on the EU and US bio-economies (feedstock, biofuels, by-products, and related competing crops) and major trade partners in these markets. The analysis develops a multi-market model that incorporates bilateral trade flows (US to EU, EU to US, and similarly with third countries) and is calibrated to OECD-FAO baseline for 2013–2022 to account for recent policy decisions. The major policy reforms from a TTIP involve tariff and TRQ liberalization and their direct contractionary impact on US sugar supply, EU biofuel production, and indirect negative effect on US HFCS ...


Predator Exclosures, Predator Removal, And Habitat Improvement Increase Nest Success Of Snowy Plovers In Oregon, Usa, Stephen J. Dinsmore, David J. Lauten, Kathleen A. Castelein, Eleanor P. Gaines, Mark A. Stern Nov 2014

Predator Exclosures, Predator Removal, And Habitat Improvement Increase Nest Success Of Snowy Plovers In Oregon, Usa, Stephen J. Dinsmore, David J. Lauten, Kathleen A. Castelein, Eleanor P. Gaines, Mark A. Stern

Natural Resource Ecology and Management Publications

Management to increase reproductive success is commonly used to aid recovery of threatened and endangered species. The Western Snowy Plover (Charadrius nivosus nivosus) breeds from coastal Washington, USA, to Baja California, Mexico, and in disjunct interior sites. The Pacific coast population is federally listed as Threatened; habitat loss and nest loss to a suite of terrestrial and avian predators are thought to be primary factors limiting population growth in this species. In coastal Oregon, USA, a consortium of state and federal management agencies deployed nest exclosures on active Snowy Plover nests, initiated a lethal predator management program, and conducted local-scale ...


Success Stories In Sustainable Agriculture: Helping Iowa Producers, Arlene E. Enderton Nov 2014

Success Stories In Sustainable Agriculture: Helping Iowa Producers, Arlene E. Enderton

Leopold Center Publications and Papers

Leopold Center support over three years has helped Ajay Nair, assistant professor in Horticulture, set up the ISU Sustainable Vegetable Production Lab, a research and education program to help small producers in Iowa.


Abstracts Of Recent Leopold Center Projects, Leopold Center For Sustainable Agriculture Nov 2014

Abstracts Of Recent Leopold Center Projects, Leopold Center For Sustainable Agriculture

Leopold Center Publications and Papers

Read abstracts of research, education and demonstration projects that received funds from the Leopold Center. The 32-page document includes more than 350 grant projects completed from 1996 through 2014, listed by topic and year of completion.


Understanding Engineering Students' Perceptions And Knowledge About Sustainable Development And Sustainability, Bhavna Sharma, Brian L. Steward, Say K. Ong, Fernando E. Miguez Oct 2014

Understanding Engineering Students' Perceptions And Knowledge About Sustainable Development And Sustainability, Bhavna Sharma, Brian L. Steward, Say K. Ong, Fernando E. Miguez

Agricultural and Biosystems Engineering Conference Proceedings and Presentations

The Sustainable Engineering and International Development course was first offered to engineering majors at the Iowa State University (ISU) in 2005. The course is focused on describing, discussing and comparing the key concepts of sustainability, sustainable development and sustainable engineering. In 2005, sustainability was not a major part of the engineering curricula and students had little to no knowledge about these concepts. Nine years later, sustainability has become an integral part of our daily lives. In this study, we wanted to understand student perceptions, knowledge, and understanding of sustainability, sustainable development and its implementation across various engineering systems. The assessment ...


Anthropogenic Disturbance And Environmental Associations With Fish Assemblage Structure In Two Nonwadeable Rivers, T. P. Parks, M. C. Quist, Clay L. Pierce Oct 2014

Anthropogenic Disturbance And Environmental Associations With Fish Assemblage Structure In Two Nonwadeable Rivers, T. P. Parks, M. C. Quist, Clay L. Pierce

Natural Resource Ecology and Management Publications

Nonwadeable rivers are unique ecosystems that support high levels of aquatic biodiversity, yet they have been greatly altered by human activities. Although riverine fish assemblages have been studied in the past, we still have an incomplete understanding of how fish assemblages respond to both natural and anthropogenic influences in large rivers. The purpose of this study was to evaluate associations between fish assemblage structure and reach-scale habitat, dam, and watershed land use characteristics. In the summers of 2011 and 2012, comprehensive fish and environmental data were collected from 33 reaches in the Iowa and Cedar rivers of eastern-central Iowa. Canonical ...


Leopold Letter Fall 2014, Leopold Center For Sustainable Agriculture Oct 2014

Leopold Letter Fall 2014, Leopold Center For Sustainable Agriculture

Leopold Letter

ALL THINGS COVER: Cover crops have been the watch word this year – producers are trying or seeking more information about them. The Leopold Center has long invested in cover crops research, with five current projects seeking to fill in the knowledge gaps. Sometimes trying new things requires a little boost, as Director Mark Rasmussen admits, and Distinguished Fellow Fred Kirschenmann asks whether optimization is the answer or a flawed reaction to our current challenges.

OTHER FEATURES: Meet our 2014 Spencer Award winners – two people who are leaders in their community, take in the many activities of our local food team ...


Re-Evaluating Neonatal-Age Models For Ungulates: Does Model Choice Affect Survival Estimates?, Troy W. Grovenburg, Kevin L. Monteith, Christopher N. Jacques, Robert W. Klaver, Christopher S. Deperno, Todd J. Brinkman, Kyle B. Monteith, Sophie L. Gilbert, Joshua B. Smith, Vernon C. Bleich, Christopher C. Swanson, Jonathan A. Jenks Sep 2014

Re-Evaluating Neonatal-Age Models For Ungulates: Does Model Choice Affect Survival Estimates?, Troy W. Grovenburg, Kevin L. Monteith, Christopher N. Jacques, Robert W. Klaver, Christopher S. Deperno, Todd J. Brinkman, Kyle B. Monteith, Sophie L. Gilbert, Joshua B. Smith, Vernon C. Bleich, Christopher C. Swanson, Jonathan A. Jenks

Natural Resource Ecology and Management Publications

New-hoof growth is regarded as the most reliable metric for predicting age of newborn ungulates, but variation in estimated age among hoof-growth equations that have been developed may affect estimates of survival in staggered-entry models. We used known-age newborns to evaluate variation in age estimates among existing hoof-growth equations and to determine the consequences of that variation on survival estimates. During 2001–2009, we captured and radiocollared 174 newborn (≤24-hrs old) ungulates: 76 white-tailed deer (Odocoileus virginianus) in Minnesota and South Dakota, 61 mule deer (O. hemionus) in California, and 37 pronghorn (Antilocapra americana) in South Dakota. Estimated age of ...


Impact Of Ethanol Mandates On Fuel Prices When Ethanol And Gasoline Are Imperfect Substitutes, Sebastien Pouliot, Bruce A. Babcock Sep 2014

Impact Of Ethanol Mandates On Fuel Prices When Ethanol And Gasoline Are Imperfect Substitutes, Sebastien Pouliot, Bruce A. Babcock

CARD Working Papers

Past studies that examine the impact of ethanol mandates on fuel prices make the assumption that ethanol and gasoline are perfect substitutes because they are both sources of energy in transportation fuels. These studies, however, have been of limited use in informing current policy debates because the short- to medium-run reality is one of strong regulatory and infrastructure rigidities that restrict how ethanol can be consumed in the United States. Our objective here is to improve understanding of how these rigidities change the findings of existing studies. We accomplish this by estimating the impacts of higher ethanol mandates using a ...


Effects Of Native Perennial Vegetation Buffer Strips On Dissolved Organic Carbon In Surface Runoff From An Agricultural Landscape, Tomorra Elizabeth Smith, Randall K. Kolka, Xiaobo Zhou, Matthew J. Helmers, Richard M. Cruse, Mark D. Tomer Aug 2014

Effects Of Native Perennial Vegetation Buffer Strips On Dissolved Organic Carbon In Surface Runoff From An Agricultural Landscape, Tomorra Elizabeth Smith, Randall K. Kolka, Xiaobo Zhou, Matthew J. Helmers, Richard M. Cruse, Mark D. Tomer

Agricultural and Biosystems Engineering Publications

Dissolved organic carbon (DOC) constitutes a small yet important part of a watershed’s carbon budget because it is mobile and biologically active. Agricultural conservation practices such as native perennial vegetation (NPV) strips will influence carbon cycling of an upland agroecosystem, and could affect how much DOC enters streams in runoff, potentially affecting aquatic ecosystems. In a study conducted in Iowa (USA), four treatments with strips of NPV varying in slope position and proportion of area were randomly assigned among 12 small agricultural watersheds in a balanced incomplete block design. Runoff samples from 2008 to 2010 were analyzed for DOC ...


Identifying Sampling Locations For Field-Scale Soil Moisture Estimation Using K-Means Clustering, Zachary J. Van Arkel, Amy L. Kaleita Aug 2014

Identifying Sampling Locations For Field-Scale Soil Moisture Estimation Using K-Means Clustering, Zachary J. Van Arkel, Amy L. Kaleita

Agricultural and Biosystems Engineering Publications

Identifying and understanding the impact of field-scale soil moisture patterns is currently limited by the time and resources required to do sufficient monitoring. This study uses K-means clustering to find critical sampling points to estimate field-scale near-surface soil moisture. Points within the field are clustered based upon topographic and soils data and the points representing the center of those clusters are identified as the critical sampling points. Soil moisture observations at 42 sites across the growing seasons of 4 years were collected several times per week. Using soil moisture observations at the critical sampling points and the number of points ...


Unexpected Effects Of Chitin, Cellulose, And Lignin Addition On Soil Dynamics In A Wet Tropical Forest, Ann E. Russell Aug 2014

Unexpected Effects Of Chitin, Cellulose, And Lignin Addition On Soil Dynamics In A Wet Tropical Forest, Ann E. Russell

Natural Resource Ecology and Management Publications

Decades of studies on the role of decomposition in carbon (C) and nitrogen (N) cycling have focused on organic matter (OM) of plant origin. Despite potentially large inputs of belowground OM from fungal cell walls and invertebrate exoskeletons, studies of the decomposability of their major constituent, chitin, are scarce. To explore effects on soil C dynamics of chitin, in comparison with two plant-derived chemicals, cellulose and lignin, I conducted a field-based chemical-addition experiment. The design contained three chemical treatments plus a control, with four replicates in each of two species of tropical trees grown in plantations. The chemicals were added ...


Laboratory-Scale Fractionation Of Distillers Dried Grains With Solubles (Ddgs), Congmu Zhang, Kun Xie, Ming-Hsun Cheng, Kurt A. Rosentrater Jul 2014

Laboratory-Scale Fractionation Of Distillers Dried Grains With Solubles (Ddgs), Congmu Zhang, Kun Xie, Ming-Hsun Cheng, Kurt A. Rosentrater

Agricultural and Biosystems Engineering Conference Proceedings and Presentations

The objective of this project was to separate distillers dried grains with solubles (DDGS) into high protein and high fiber fractions, in order to improve value and utility as a livestock feed. This project used a laboratory-scale cylindrical blower (Iowa blower) and a laboratory-scale gravity table (Whippet V-80 separator, Sutton, Steele & Steele, Inc.). The raw DDGS was sieved into multiple streams using 10 mesh, 20 mesh and 40 mesh screens. The 10-20 mesh fraction and 20-40 mesh fraction were then run on the blower and the separator separately, using the same settings for air velocity in the range of 0 ...


Economic And Environmental Analysis Of Farm-Scale Integrated Ethanol And Biodiesel Production Using Locally-Available Biomass, Bailley A. Richardson, Patrick J. Benson, Kurt A. Rosentrater Jul 2014

Economic And Environmental Analysis Of Farm-Scale Integrated Ethanol And Biodiesel Production Using Locally-Available Biomass, Bailley A. Richardson, Patrick J. Benson, Kurt A. Rosentrater

Agricultural and Biosystems Engineering Conference Proceedings and Presentations

With increased technology and economic opportunities, demand for energy and fuels in developing countries is growing exponentially to run processes and improve lifestyles, but rural areas may not have access. It is thus important to identify possible sources of energy for developing rural areas, especially those sources which are renewable and locally produced. The objective of this study was to develop a computer model to assess the viability of developing integrated biofuel production systems using biomass materials specific to Mozambique and India. The models considered various system capacities and production scenarios. Estimates of processing costs, along with other economic factors ...


Economic And Environmental Analysis Of Farm-Scale Biodigesters To Produce Energy For Kitchen Stove Use, Zachary P. Bartlett, Alexandra Olivares, Yang Lu, Kurt A. Rosentrater Jul 2014

Economic And Environmental Analysis Of Farm-Scale Biodigesters To Produce Energy For Kitchen Stove Use, Zachary P. Bartlett, Alexandra Olivares, Yang Lu, Kurt A. Rosentrater

Agricultural and Biosystems Engineering Conference Proceedings and Presentations

Developing countries throughout the world currently fuel kitchen stoves for cooking by burning wood which is responsible for many health and environmental problems. Producing fuel for cooking via anaerobic digestion is a very ecofriendly and resourceful solution that is being explored. To determine the sustainability of anaerobic digestion throughout these regions, multiple biodigester designs were tested under conditions specific to various third-world countries; the countries tested were Nicaragua, Bolivia, Nigeria, India and Indonesia. Factors to be considered included the use of local biomass resources and building materials. Determining the fueling efficiency of anaerobic digestion in comparison to burning wood consisted ...


Small Changes, Big Impacts: Prairie Conservation Strips, Mary A. Harris, Geetha Iyer Jul 2014

Small Changes, Big Impacts: Prairie Conservation Strips, Mary A. Harris, Geetha Iyer

Natural Resource Ecology and Management Publications

Agriculture in Iowa owes its immense productivity to an extreme trade-off. Once, perennial prairie covered 85 percent of the state, and its deep root network built and held together a fertile topsoil layer many feet deep. Now, more than 85 percent is in agricultural production, with the majority in row crops.


Evaluation Of Trophic Niche Overlap Between Native Fishes And Young-Of-The-Year Common Carp, Michael J. Weber, Jessica M. Howell, Michael L. Rown Jul 2014

Evaluation Of Trophic Niche Overlap Between Native Fishes And Young-Of-The-Year Common Carp, Michael J. Weber, Jessica M. Howell, Michael L. Rown

Michael J Weber Dr

Common carp Cyprinus carpio is a ubiquitous invasive species that commonly imposes negative effects on aquatic ecosystems. However, research evaluating the effects of carp on native fishes is limited. Carp are highly fecund and larvae and juveniles can be abundant. If age-0 carp use similar prey resources as native fishes, they may compete if food becomes limited. We used traditional diet analysis for samples during Jul. and Aug. 2008 in Brant Lake. Stable sotopes were used for samples collected during Aug. and Sep. 2009 in Brant Lake and Lake Sinai to examine prey resource use by age-0 carp and four ...


Leopold Letter Summer 2014, Leopold Center For Sustainable Agriculture Jul 2014

Leopold Letter Summer 2014, Leopold Center For Sustainable Agriculture

Leopold Letter

CULTIVATING CHANGE: Many people are interested in getting their food locally, but what about energy? The Leopold Center has been helping the University of Iowa cultivate locally-grown biomass for power on campus, while another new model is taking local food to the workplace. Meanwhile, Director Mark Rasmussen looks at complicated chemical interactions and what could be their environmental consequences. Distinguished Fellow Fred Kirschenmann offers strategies for living in a hotter world.

OTHER FEATURES: We asked researchers how they would improve soil health. You'll also learn about the impacts of a program to reach landowners, a report from our local ...


Effects Of Set-Aside Conservation Practices On Bird Community Structure Within An Intensive Agricultural Landscape, Ross Robert Conover, Stephen J. Dinsmore, L. Wes Burger Jr. Jul 2014

Effects Of Set-Aside Conservation Practices On Bird Community Structure Within An Intensive Agricultural Landscape, Ross Robert Conover, Stephen J. Dinsmore, L. Wes Burger Jr.

Natural Resource Ecology and Management Publications

Creating and restoring patches of noncrop early-succession vegetation within agricultural landscapes may mitigate grassland bird population declines caused by agricultural land use and intensification. Achieving this goal requires an ability to balance avian benefits with agronomics, which may be facilitated by understanding how bird communities respond to various conservation practices. We evaluated bird richness, abundance, Shannon diversity, and Total Avian Conservation Value in 20 replicates of four Conservation Reserve Program practices in an intensive rowcrop agricultural landscape in the Mississippi Alluvial Valley from May–Jul., 2005–2007. Conservation practices included: (1) large blocks of structurally-diverse early-succession vegetation (6–8 y ...


Genotypic Variability For Tuber Yield, Biomass, And Drought Tolerance In Jerusalem Artichoke Germplasm, Ruttanachira Ruttanaprasert, Poramate Banterng, Sanun Jogloy, Nimitr Vorasoot, Thawan Kesmala, Rameshwar S. Kanwar, Carl C. Holbrook, Aran Patanothai Jun 2014

Genotypic Variability For Tuber Yield, Biomass, And Drought Tolerance In Jerusalem Artichoke Germplasm, Ruttanachira Ruttanaprasert, Poramate Banterng, Sanun Jogloy, Nimitr Vorasoot, Thawan Kesmala, Rameshwar S. Kanwar, Carl C. Holbrook, Aran Patanothai

Agricultural and Biosystems Engineering Publications

Jerusalem artichoke could be an alternative feedstock for bioenergy during times when there are shortages of other raw materials for the ethanol industry. However, insufficient water under rainfed conditions is a major cause of Jerusalem artichoke losses. Genetic variation for drought tolerance is an essential prerequisite for the development of Jerusalem artichoke cultivars with improved drought tolerance. The objectives of this study were to determine the effects of drought stress on tuber dry weight and biomass and to investigate the genotypic variability in Jerusalem artichoke germplasm. The line-source sprinkler technique was used to compare moisture responses of a range of ...


Transport And Persistence Of Tylosin-Resistant Enterococci, Erm Genes, And Tylosin In Soil And Drainage Water From Fields Receiving Swine Manure, Jason L. Garder, Thomas B. Moorman, Michelle L. Soupir Jun 2014

Transport And Persistence Of Tylosin-Resistant Enterococci, Erm Genes, And Tylosin In Soil And Drainage Water From Fields Receiving Swine Manure, Jason L. Garder, Thomas B. Moorman, Michelle L. Soupir

Agricultural and Biosystems Engineering Publications

Land application of manure from tylosin-treated swine introduces tylosin, tylosin-resistant enterococci, and erythromycin resistant rRNA methylase (erm) genes, which confer resistance to tylosin. This study documents the persistence and transport of tylosin-resistant enterococci,erm genes, and tylosin in tile-drained chisel plow and no-till agricultural fields treated with liquid swine manure in alternating years. Between 70 and 100% of the enterococci in manure were resistant to tylosin and ermB concentrations exceeded 108 copies g−1 manure, while the mean ermF concentrations exceeded 107 copies g−1 manure (ermT was not detected). The mean concentration of tylosin ...