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Full-Text Articles in Life Sciences

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 ...


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 ...


Contamination Of Water Resources By Pathogenic Bacteria, Pramod K. Pandey, Philip H. Kass, Michelle L. Soupir, Sagor Biswas, Vijay P. Singh Jun 2014

Contamination Of Water Resources By Pathogenic Bacteria, Pramod K. Pandey, Philip H. Kass, Michelle L. Soupir, Sagor Biswas, Vijay P. Singh

Agricultural and Biosystems Engineering Publications

Water-borne pathogen contamination in water resources and related diseases are a major water quality concern throughout the world. Increasing interest in controlling water-borne pathogens in water resources evidenced by a large number of recent publications clearly attests to the need for studies that synthesize knowledge from multiple fields covering comparative aspects of pathogen contamination, and unify them in a single place in order to present and address the problem as a whole. Providing a broader perceptive of pathogen contamination in freshwater (rivers, lakes, reservoirs, groundwater) and saline water (estuaries and coastal waters) resources, this review paper attempts to develop the ...


Development Of Sustainable Corn Stover Harvest Strategies For Cellulosic Ethanol Production, Stuart J. Birrell, Douglas L. Karlen, Adam Wirt Jun 2014

Development Of Sustainable Corn Stover Harvest Strategies For Cellulosic Ethanol Production, Stuart J. Birrell, Douglas L. Karlen, Adam Wirt

Agricultural and Biosystems Engineering Publications

To prepare for a 2014 launch of commercial scale cellulosic ethanol production from corn/maize (Zea mays L.) stover, POET-DSM near Emmetsburg, IA has been working with farmers, researchers, and equipment dealers through “Project Liberty” on harvest, transportation, and storage logistics of corn stover for the past several years. Our objective was to evaluate seven stover harvest strategies within a 50-ha (125 acres) site on very deep, moderately well to poorly drained Mollisols, developed in calcareous glacial till. The treatments included the following: conventional grain harvest (no stover harvest), grain plus a second-pass rake and bale stover harvest, and single-pass ...


Nitrogen And Carbon Dynamics In Prairie Vegetation Strips Across Topographical Gradients In Mixed Central Iowa Agroecosystems, Marlín Pérez-Suárez, Michael J. Castellano, Randall K. Kolka, Heidi Asbjornsen, Matthew J. Helmers Apr 2014

Nitrogen And Carbon Dynamics In Prairie Vegetation Strips Across Topographical Gradients In Mixed Central Iowa Agroecosystems, Marlín Pérez-Suárez, Michael J. Castellano, Randall K. Kolka, Heidi Asbjornsen, Matthew J. Helmers

Agricultural and Biosystems Engineering Publications

Reductions of nitrogen (N) export from agricultural lands because of changes in specific N stocks and fluxes by incorporation of small amounts of prairie vegetation strips (PVS) are poorly understood. The primary objective of this study was to evaluate the effect of the presence and topographical position of PVS on soil and plant carbon (C) and N stocks relative to annual crop and native prairie vegetation. The study was implemented within three small adjacent watersheds, treated with one of the following cover types: (1) 100% row-crop agriculture (CROP); (2) 20% prairie vegetation (PVS) distributed along the contour across three topographical ...


Analytical Methods For Chemical And Sensory Characterization Of Scent-Markings In Large Wild Mammals: A Review, Simone B. Soso, Jacek A. Koziel, Anna K. Johnson, Young Jin Lee, W. Sue Fairbanks Mar 2014

Analytical Methods For Chemical And Sensory Characterization Of Scent-Markings In Large Wild Mammals: A Review, Simone B. Soso, Jacek A. Koziel, Anna K. Johnson, Young Jin Lee, W. Sue Fairbanks

Agricultural and Biosystems Engineering Publications

In conjoining the disciplines of “ethology” and “chemistry” the field of “Ethochemistry” has been instituted. Ethochemistry is an effective tool in conservation efforts of endangered species and the understanding of behavioral patterns across all species. Chemical constituents of scent-markings have an important, yet poorly understood function in territoriality, reproduction, dominance, and impact on evolutionary biology, especially in large mammals. Particular attention has recently been focused on scent-marking analysis of great cats (Kalahari leopards (Panthera pardus), puma (Puma concolor) snow leopard (Panthera uncia), African lions (Panthera leo), cheetahs (Acinonyx jubatus), and tigers (Panthera tigris)) for the purpose of conservation. Sensory analyses ...


Effects Of Tillage And Application Rate On Atrazine Transport To Subsurface Drainage: Evaluation Of Rzwqm Using A Six-Year Field Study, Robert W. Malone, B. T. Nolan, Liwang Ma, Rameshwar S. Kanwar, Carl H. Pederson, Philip Heilman Jan 2014

Effects Of Tillage And Application Rate On Atrazine Transport To Subsurface Drainage: Evaluation Of Rzwqm Using A Six-Year Field Study, Robert W. Malone, B. T. Nolan, Liwang Ma, Rameshwar S. Kanwar, Carl H. Pederson, Philip Heilman

Agricultural and Biosystems Engineering Publications

Well tested agricultural system models can improve our understanding of the water quality effects of management practices under different conditions. The Root Zone Water Quality Model (RZWQM) has been tested under a variety of conditions. However, the current model's ability to simulate pesticide transport to subsurface drain flow over a long term period under different tillage systems and application rates is not clear. Therefore, we calibrated and tested RZWQM using six years of data from Nashua, Iowa. In this experiment, atrazine was spring applied at 2.8 (1990–1992) and 0.6 kg/ha/yr (1993–1995) to two ...


Strips: Science-Based Trials Of Row Crops Integrated With Prairie Strips, Matthew J. Helmers Jan 2014

Strips: Science-Based Trials Of Row Crops Integrated With Prairie Strips, Matthew J. Helmers

Agricultural and Biosystems Engineering Publications

Growing demand for agricultural products to supply food, feed, fiber, and fuel comes at a time of intensified pressure by the public as well as by local and federal government agencies to reduce the impacts of agricultural production on water quality and biodiversity. Midwest land under heavy agricultural production has been identified as a major contributor to nitrogen and phosphorus losses to downstream water systems and to hypoxia in the Gulf of Mexico.


Growth Performance And Economic Analysis Of Indian Major Carps And Tilapia In Rainwater Ponds, Pramod K. Pandey, Laxmi N. Sethi, Limbraj P. Pholane, Sudhindra N. Panda, Vinay K. Pandey, Sagor Biswas, Michelle L. Soupir Jan 2014

Growth Performance And Economic Analysis Of Indian Major Carps And Tilapia In Rainwater Ponds, Pramod K. Pandey, Laxmi N. Sethi, Limbraj P. Pholane, Sudhindra N. Panda, Vinay K. Pandey, Sagor Biswas, Michelle L. Soupir

Agricultural and Biosystems Engineering Publications

Enhancing water resources is crucially important for improving food production in rainfed regions. The income of rural people in these regions is mainly tied with water availability. One option is disseminating rainwater harvesting for conserving rainwater and utilizing it for food production. Here we propose a rainwater harvesting method, which helps to conserve rainwater in the rainy season, provide water storage for rearing fish and facilitate supplemental irrigation to crops in the dry season. To verify the suitability of rainwater harvesting approach for improving food production and rural income, here we conducted a field study, which involved designing rainwater harvesting ...


Predicting Time Cattle Spend In Streams To Quantify Direct Deposition Of Manure, Shannon B. Brown, Charles D. Ikenberry, Michelle L. Soupir, Justin J. Bisinger, James R. Russell Jan 2014

Predicting Time Cattle Spend In Streams To Quantify Direct Deposition Of Manure, Shannon B. Brown, Charles D. Ikenberry, Michelle L. Soupir, Justin J. Bisinger, James R. Russell

Agricultural and Biosystems Engineering Publications

Current methods to predict bacterial loads into streams resulting from direct deposition of manure by livestock do not consider factors that influence livestock behavior. Data from three studies that monitored spatial behavior of cattle through GPS were used to develop a new method with increased temporal resolution and consideration of environmental factors to predict the time that cattle spend in streams. Information on relative location of the cattle to the pasture stream was used to calculate the number of hours a cow spent in the stream, and from that the load of bacteria deposited directly into the stream. Ultimately, four ...


Nutrient Removal By Prairie Filter Strips In Agricultural Landscapes, Xiaobo Zhou, Matthew J. Helmers, Heidi Asbjornsen, Randall K. Kolka, Mark D. Tomer, Richard M. Cruse Jan 2014

Nutrient Removal By Prairie Filter Strips In Agricultural Landscapes, Xiaobo Zhou, Matthew J. Helmers, Heidi Asbjornsen, Randall K. Kolka, Mark D. Tomer, Richard M. Cruse

Agricultural and Biosystems Engineering Publications

Nitrogen (N) and phosphorus (P) from agricultural landscapes have been identified as primary sources of excess nutrients in aquatic systems. The main objective of this study was to evaluate the effectiveness of prairie filter strips (PFS) in removing nutrients from cropland runoff in 12 small watersheds in central Iowa. Four treatments with PFS of different spatial coverage and distribution (No-PFS, 10% PFS, 10% PFS with strips, and 20% PFS with strips) were arranged in a balanced incomplete block design across four blocks in 2007. A no-tillage two-year corn (Zea mays L.) –soybean (Glycine max [L.] Merr.) rotation was grown in ...


Assessing Linkages Between E. Coli Levels In Streambed Sediment And Overlying Water In An Agricultural Watershed In Iowa During The First Heavy Rain Event Of The Season, Pramod K. Pandey, Michelle L. Soupir Jan 2014

Assessing Linkages Between E. Coli Levels In Streambed Sediment And Overlying Water In An Agricultural Watershed In Iowa During The First Heavy Rain Event Of The Season, Pramod K. Pandey, Michelle L. Soupir

Agricultural and Biosystems Engineering Publications

This study involved field observations in Squaw Creek watershed, located in central Iowa, to investigate the impact of a heavy rain event (rainfall of 71 mm in 24 h) on E. coli levels in the streambed sediment and overlying water. We assessed relationships between streamflow and E. coli and nutrient levels in the water column and streambed sediment. The results showed that during a heavy rain event, E. coli levels in the water column varied considerably, ranging from 360 to 37,553 CFU per 100 mL with a mean of 7,598 CFU per 100 mL. Elevated streamflow resulted in ...


Vegetative Treatment System Impacts On Groundwater Quality, Daniel S. Andersen, Robert Burns, Matthew J. Helmers, Lara B. Moody Jan 2014

Vegetative Treatment System Impacts On Groundwater Quality, Daniel S. Andersen, Robert Burns, Matthew J. Helmers, Lara B. Moody

Agricultural and Biosystems Engineering Publications

Increased environmental awareness has prompted the need for improved feedlot runoff control. Vegetative treatment systems (VTSs) provide a cost-effective option that may enhance environmental security by protecting water quality. Vegetative treatment systems are typically designed on the basis of hydraulic performance, which may result in excess application of some nutrients, specifically nitrogen and phosphorus. Groundwater quality monitoring is required to determine the effect, if any, that VTSs have on groundwater. Shallow groundwater (2 to 10 m) quality beneath six VTSs in Iowa was monitored over a four-year period. Monitoring wells were located upgradient, within, and downgradient of the VTSs. Groundwater ...