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Full-Text Articles in Life Sciences

Estimating Total And Bioavailable Nutrient Loading To Utah Lake From The Atmosphere, Janice Brahney Oct 2019

Estimating Total And Bioavailable Nutrient Loading To Utah Lake From The Atmosphere, Janice Brahney

Janice Brahney

Anthropogenic activities have led to increases in the emission, atmospheric transport, and deposition of key nutrients. In addition, climate change along with anthropogenic soil disturbance has led to recent increases in the mobilization and transport of soils and other particles through the atmosphere, collectively described here as dust. These increased emissions have led to growing interest and concern over the composition of atmospheric deposition and total loading of nutrients to aquatic systems. In the last several decades, much effort has been directed towards the measurement and modeling of nitrogen deposition through wet and aerosol deposition. Less is known about the ...


Impacts Of 40 Years Of Land Cover Change On Water Quality In Tampa Bay, Florida, Matthew J. Mccarthy, Frank E. Muller-Karger, Daniel Otis, Pablo Méndez-Lázaro Sep 2019

Impacts Of 40 Years Of Land Cover Change On Water Quality In Tampa Bay, Florida, Matthew J. Mccarthy, Frank E. Muller-Karger, Daniel Otis, Pablo Méndez-Lázaro

Frank E. Muller-Karger

Land cover changes in the Tampa Bay watershed (Florida) over the past four decades were examined along with precipitation and wind observations to help understand causes of long-term changes in turbidity and chlorophyll concentration within the Tampa Bay estuary. Water quality showed a statistically significant relationship to land cover fraction in the watershed compared to long-term precipitation or wind stress. Redundancy Analyses with Akaike’s Information Criterion and non-parametric multiple regressions determined that turbidity and chlorophyll concentration decreased bay-wide from 1974–2012 with increased developed land fraction (R2 > 0.75, p-value < 0.05). Various segments of the estuary showed different significant responses to developed land (R2 > 0.75, p-value < 0.05), agricultural land (R2 > 0.93, p-value < 0.02), bare land (R2 = 0.77, p-value = 0.001), and wind stress (R2 = 0.91, p-value = 0.04) at different times of year.


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 Aug 2019

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 ...


Future Prospects For Corn As A Biofuel Crop, Kenneth J. Moore, Douglas L. Karlen, Kendall R. Lamkey Aug 2019

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 ...


Comparison Of Microbial Water Quality Parameters Of Four Geographically Similar Creeks In Northeast Tennessee, Kimberlee K. Hall, L. K. Gallagher, Brian G. Evanshen, Kurt J. Maier, Phillip R. Scheuerman Oct 2018

Comparison Of Microbial Water Quality Parameters Of Four Geographically Similar Creeks In Northeast Tennessee, Kimberlee K. Hall, L. K. Gallagher, Brian G. Evanshen, Kurt J. Maier, Phillip R. Scheuerman

Phillip R. Scheuerman

Four creeks within the Watauga River watershed in Northeast Tennessee are routinely monitored for water quality assessments. To identify sources and monitor remediation, Sinking Creek, Cash Hollow Creek, Buffalo Creek and Boones Creek are monitored for chemical and microbial parameters. These parameters include phosphates, nitrates, BOD and fecal coliforms. Sinking Creek is a tributary of the Watauga River with 10 miles of impaired water. Cash Hollow Creek enters the Watauga River at river mile 11.4 with 3.4 miles of impaired water. Boones Creek contains 18.6 impaired miles while the status of water quality in Buffalo Creek is ...


Annual Swine Manure Applications To Soybean Under Corn-Soybean Rotation, Allah Bakhsh, Rameshwar S. Kanwar, James L. Baker, John E. Sawyer, Antonio P. Mallarino Jul 2016

Annual Swine Manure Applications To Soybean Under Corn-Soybean Rotation, Allah Bakhsh, Rameshwar S. Kanwar, James L. Baker, John E. Sawyer, Antonio P. Mallarino

John E. Sawyer

The response of a corn-soybean rotation system receiving fall manure application to both corn and soybean is not well understood in terms of its impact on nitrate leaching to subsurface drainage water and crop yields. This field study was conducted from 2001 through 2005 with the key objective of determining the effects of manure application to both corn and soybean on NO3-N concentrations in subsurface drainage water and corn-soybean yields. The study was conducted on 0.4 ha plots instrumented with state-of-the-art subsurface drainage monitoring systems at the Iowa State University research center, Nashua, Iowa. Nitrogen application rates from liquid ...


The Shellfish Corner -- Water Quality And Culture Of Shellfish In Prohibited Waters, Michael A. Rice Jan 2016

The Shellfish Corner -- Water Quality And Culture Of Shellfish In Prohibited Waters, Michael A. Rice

Michael A Rice

In the United States, water quality standards for shellfishing and shellfish aquaculture waters have been governed since 1925 by the National Shellfish Sanitation Program (NSSP) first administered by the United States Public Health Service. With the greater popularity of aquacultured shellfish in the United States and the growth of market demand, seed availability is cited as one of the most pressing issues for the industry. The early recognition by ISSC of shellfish seed under certain conditions as being exempt from NSSP water quality classification requirements has already removed one of the largest regulatory barriers to expansion of seed production in ...


Evaluating And Predicting Agricultural Management Effects Under Tile Drainage Using Modified Apsim, Robert W. Malone, N. Huth, P. S. Carberry, Liwang Ma, Thomas C. Kaspar, Douglas L. Karlen, T. Meade, Ramesh S. Kanwar, Philip Heilman Dec 2015

Evaluating And Predicting Agricultural Management Effects Under Tile Drainage Using Modified Apsim, Robert W. Malone, N. Huth, P. S. Carberry, Liwang Ma, Thomas C. Kaspar, Douglas L. Karlen, T. Meade, Ramesh S. Kanwar, Philip Heilman

Douglas L Karlen

An accurate and management sensitive simulation model for tile-drained Midwestern soils is needed to optimize the use of agricultural management practices (e.g., winter cover crops) to reduce nitrate leaching without adversely affecting corn yield. Our objectives were to enhance the Agricultural Production Systems Simulator (APSIM) for tile drainage, test the modified model for several management scenarios, and then predict nitrate leaching with and without winter wheat cover crop. Twelve years of data (1990–2001) from northeast Iowa were used for model testing. Management scenarios included continuous corn and corn–soybean rotations with single or split N applications. For 38 ...


Corn-Soybean And Alternative Cropping Systems Effects On No 3 -N Leaching Losses In Subsurface Drainage Water, Rameshwar S. Kanwar, Richard M. Cruse, Mohammadreza Ghaffarzadeh, Allah Bakhsh, Douglas Karlen, Theodore B. Bailey Dec 2015

Corn-Soybean And Alternative Cropping Systems Effects On No 3 -N Leaching Losses In Subsurface Drainage Water, Rameshwar S. Kanwar, Richard M. Cruse, Mohammadreza Ghaffarzadeh, Allah Bakhsh, Douglas Karlen, Theodore B. Bailey

Douglas L Karlen

Alternative cropping systems can improve resource use efficiency, increase corn grain yield, and help in reducing negative impacts on the environment. A 6-yr (1993 to 1998) field study was conducted at the Iowa State University’s Northeastern Research Center near Nashua, Iowa, to evaluate the effects of non-traditional cropping systems [strip inter cropping (STR)-corn (Zea mays L.)/soybean (Glycine max L.)/oats (Avina sativa L.)]; alfalfa rotation (ROT)-3-yr (1993 to 1995) alfalfa (Medicago sativa L.) followed by corn in 1996, soybean in 1997, and oats in 1998), and traditional cropping system (corn after soybean (CS) and soybean after ...


Cropping System Effects On No3-N Loss With Subsurface Drainage Water, Allah Bakhsh, Rameshwar S. Kanwar, Theodore B. Bailey, Cynthia A. Cambardella, Douglas Karlen, Thomas S. Colvin Dec 2015

Cropping System Effects On No3-N Loss With Subsurface Drainage Water, Allah Bakhsh, Rameshwar S. Kanwar, Theodore B. Bailey, Cynthia A. Cambardella, Douglas Karlen, Thomas S. Colvin

Douglas L Karlen

An appropriate combination of tillage and nitrogen management practices will be necessary to develop sustainable farming practices. A six–year (1993–1998) field study was conducted on subsurface–drained Clyde–Kenyon–Floyd soils to quantify the impact of two tillage systems (chisel plow vs. no tillage) and two N fertilizer management practices (preplant single application vs. late–spring soil test based application) on nitrate–nitrogen (NO3–N) leaching loss with subsurface drain discharge from corn (Zea mays L.) soybean (Glycine max L.) rotation plots. Preplant injected urea ammonium nitrate solution (UAN) fertilizer was applied at the rate of 110 kg ...


Alternative N Fertilizer Management Strategies Effects On Subsurface Drain Effluent And N Uptake, David L. Bjorneberg, Douglas L. Karlen, Rameshwar S. Kanwar, Cynthia A. Cambardella Dec 2015

Alternative N Fertilizer Management Strategies Effects On Subsurface Drain Effluent And N Uptake, David L. Bjorneberg, Douglas L. Karlen, Rameshwar S. Kanwar, Cynthia A. Cambardella

Douglas L Karlen

Demonstrating positive environmental benefits of alternative N fertilizer management strategies, without adversely affecting crop growth or yield, was a major goal for the Midwest Management Systems Evaluation Areas (MSEA) program. Our project objectives within this program were to quantify the effects of split- and single-N fertilization strategies on NO3-N concentration and loss in subsurface drain effluent and N accumulation and yield of corn (Zea mays L.) and soybean [Glycine max (L.) Merr.]. The study was conducted on glacial till derived soils in northeast Iowa from 1993 through 1995 using no-till and chisel plow tillage treatments. One-third of the 2,611 ...


Establishing A National Shellfish Sanitation Program In The Gambia, West Africa, Michael A. Rice, Foday Conteh, Karen Kent, Brian Crawford, Banja Bamba, Fatou Janha, Ismaila Bojang Jul 2015

Establishing A National Shellfish Sanitation Program In The Gambia, West Africa, Michael A. Rice, Foday Conteh, Karen Kent, Brian Crawford, Banja Bamba, Fatou Janha, Ismaila Bojang

Michael A Rice

A successful national program to assure sanitary quality of molluscan shellfish requires a multi-disciplinary and multi-agency governmental training, data collection, policy development and management effort in collaboration with members of the shellfish industry. The Tanbi Wetlands and other estuaries of Gambia support shellfisheries for oysters, Crassostrea tulipa, and the senile ark, Senelia senilis, conducted by the TRY Oyster Women’s Association. With low shellfish prices and a small local market, a Gambian National Shellfish Sanitation Program (GNSSP) was begun as a means to boost consumer confidence and allow market access to Gambia’s robust seasonal international tourism trade. Gambian officials ...


"Absolutely Part Of What We Should Be Doing": Kevin Curry, Water Filters And The International Mission Of The Modern University, Andrew C. Holman Mar 2013

"Absolutely Part Of What We Should Be Doing": Kevin Curry, Water Filters And The International Mission Of The Modern University, Andrew C. Holman

Andrew C. Holman

No abstract provided.


Report On Sanitary Shoreline Survey Within The Tanbi Wetlands National Park And Other Shellfish Harvesting Communities, The Gambia May 2012

Report On Sanitary Shoreline Survey Within The Tanbi Wetlands National Park And Other Shellfish Harvesting Communities, The Gambia

Michael A Rice

Emphasis is placed on the sanitary control of shellfish because of the direct relationship between pollution of shellfish growing areas and the transmission of diseases to humans. Shellfish borne infectious diseases are generally transmitted via a fecal - oral route. To accurately assess waters for shellfish harvesting, an evaluation of the pollution sources that are likely to affect the area is required by the NSSP. The shoreline survey is conducted of the shellfish growing area shoreline and estuary to locate pollution sources that could have an effect on the water quality of the area. The shoreline survey team visited 15 oyster ...


Results Of A Preliminary Shoreline Shellfish Sanitary Survey Near Banjul, Gambia Conducted On 18 June 2011, Kanyi Babanding, Michael A. Rice May 2011

Results Of A Preliminary Shoreline Shellfish Sanitary Survey Near Banjul, Gambia Conducted On 18 June 2011, Kanyi Babanding, Michael A. Rice

Michael A Rice

A preliminary shoreline survey was conducted along the Bund Road (frequently referred to as Bond Road) levee and the Banjul-Serrekunda Highway in the northern Tanbi Wetlands oyster harvesting area in the metropolitan Banjul area. In part this was designed as a training exercise for Gambian officials will be assuming responsibility for future shoreline surveys in the Gambia. Key identified areas of concern include the Banjul fish landing area on Bund Road utilized by a number of artisanal fishers; an over-water toilet facility for fishers near the fish landing site; evidence of illegal waste and rubbish dumping along Bund Road; an ...


Fate And Transport Of Pathogen Indicators From Pasturelands, Michelle L. Soupir Dec 2007

Fate And Transport Of Pathogen Indicators From Pasturelands, Michelle L. Soupir

Michelle L. Soupir

The U.S. EPA has identified pathogen indicators as a leading cause of impairments in rivers and streams in the U.S. Elevated levels of bacteria in streams draining the agricultural watersheds cause concern because they indicate the potential presence of pathogenic organisms. Limited understanding of how bacteria survive in the environment and are released from fecal matter and transported along overland flow pathways results in high uncertainty in the design and selection of appropriate best management practices (BMPs) and in the bacterial fate and transport models used to identify sources of pathogens.

The overall goal of this study was ...


Degradation Of Estrogens In Dairy Waste Solids: Effects Of Acidification And Temperature, D. Raj Raman, Alice C. Layton, Lara B. Moody, James P. Easter, Gary S. Sayler, Robert T. Burns Jan 2001

Degradation Of Estrogens In Dairy Waste Solids: Effects Of Acidification And Temperature, D. Raj Raman, Alice C. Layton, Lara B. Moody, James P. Easter, Gary S. Sayler, Robert T. Burns

D. Raj Raman

Manure–borne estrogens are increasingly recognized as a potential ecological hazard. However, sample–handling protocols for these compounds are not clearly delineated in the literature, nor are comparisons between assays for estrogens. A study was conducted to explore the degradation of estrogen in separated dairy manure waste solids (press cake), using three popular assay types. Estrogens were measured by enzyme–linked immunosorbent assay (ELISA), gas–chromatography mass–spectroscopy (GC–MS) and a recombinant yeast estrogen reporter assay. As measured by GC–MS, background estrone concentrations were approximately 100 ppb, while 17β–estradiol concentrations were one–third of the estrone concentration ...


Degradation Of Estrogens In Dairy Waste Solids: Effects Of Acidification And Temperature, D. Raj Raman, Alice C. Layton, Lara B. Moody, James P. Easter, Gary S. Sayler, Robert T. Burns Dec 2000

Degradation Of Estrogens In Dairy Waste Solids: Effects Of Acidification And Temperature, D. Raj Raman, Alice C. Layton, Lara B. Moody, James P. Easter, Gary S. Sayler, Robert T. Burns

Gary S. Sayler

Manure–borne estrogens are increasingly recognized as a potential ecological hazard. However, sample–handling protocols for these compounds are not clearly delineated in the literature, nor are comparisons between assays for estrogens. A study was conducted to explore the degradation of estrogen in separated dairy manure waste solids (press cake), using three popular assay types. Estrogens were measured by enzyme–linked immunosorbent assay (ELISA), gas–chromatography mass–spectroscopy (GC–MS) and a recombinant yeast estrogen reporter assay. As measured by GC–MS, background estrone concentrations were approximately 100 ppb, while 17β–estradiol concentrations were one–third of the estrone concentration ...


A Review Of Shellfish Restoration As A Tool For Coastal Water Quality Management., Michael A. Rice Nov 2000

A Review Of Shellfish Restoration As A Tool For Coastal Water Quality Management., Michael A. Rice

Michael A Rice

In many areas, coastal residents and others oppose establishment of bivalve molluscan aquaculture projects on the basis of perceived negative environmental impacts. Often overlooked are positive environmental impacts of shellfish aquaculture that can potentially mitigate the impacts of other anthropogenic activities. Filter feeding by populations of bivalve mollusks is reviewed with respect to their ability to act as an estuarine filter, increase clarity of coastal waters and facilitate the removal of nitrogen and other nutrients from eutrophic coastal waters. Most species of cultured bivalve mollusks clear particles from waters at rates of 1 to 4 L/h, and populations of ...