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Full-Text Articles in Engineering

Cyanobacterial And Microcystin Response To Nutrient Additions At Lake Fayetteville Throughout The 2021 Growing Season, Lillie Haddock May 2022

Cyanobacterial And Microcystin Response To Nutrient Additions At Lake Fayetteville Throughout The 2021 Growing Season, Lillie Haddock

Graduate Theses and Dissertations

Harmful Algal Blooms (HABs) are becoming a global concern due to their increasing distribution, frequency, intensity, and the occurrence of toxins. While it is known that eutrophication influences algal blooms, there is less known about what triggers these HABs to produce toxins, especially microcystin. In this study, we conducted 21 community bioassays at Lake Fayetteville, a hypereutrophic reservoir in Fayetteville, Arkansas, from April-November 2021 to examine how the addition of phosphorous and nitrogen influence cyanobacteria concentrations, microcystin concentrations, and microcystin toxin production. These experiments included a control, nitrogen (1.0 mg/L as KNO3), low phosphorus (0.025 mg/L as K2HPO4), high phosphorus …


Modeling Water Quantity And Quality Nonlinearities For Watershed Adaptability To Hydroclimate Extremes In Agricultural Landscapes, Juan Carlos Jaimes-Correa, Francisco Muñoz-Arriola, Shannon Bartelt-Hunt Jan 2022

Modeling Water Quantity And Quality Nonlinearities For Watershed Adaptability To Hydroclimate Extremes In Agricultural Landscapes, Juan Carlos Jaimes-Correa, Francisco Muñoz-Arriola, Shannon Bartelt-Hunt

Biological Systems Engineering: Papers and Publications

Changing water supplies and demands, inherent to climate fluctuations and human activities, are pushing for a paradigm shift in water management worldwide. The occurrence of extreme hydrometeorological and climate events such as extended wet periods and droughts, compounded with contaminants, impair the access to water resources, demanding novel designs, construction, and management across multiple hydrologic scales and biogeochemical processes. A constraint to studying hydrologic and biogeochemical disturbances and improving best management practices for water quantity and quality at the watershed scale resides in the suitable monitoring, data availability, and the creation of frameworks. We hypothesize that streamflow and contaminants, simulated …


Differential Survival Of Non-O157 Shiga Toxigenic Escherichia Coli In Simulated Cattle Feedlot Runoff, Lisa M. Durso, John E. Gilley, Daniel N. Miller Jan 2021

Differential Survival Of Non-O157 Shiga Toxigenic Escherichia Coli In Simulated Cattle Feedlot Runoff, Lisa M. Durso, John E. Gilley, Daniel N. Miller

Biological Systems Engineering: Papers and Publications

Environmental survival time is important when evaluating adverse health outcomes from foodborne pathogens. Although outbreaks associated with manure-impacted irrigation or runoff water are relatively infrequent, their broad scope, regulatory importance, and severe health outcomes highlight the need to better understand the environmental survival of manure-borne pathogens. Shiga toxigenic Escherichia coli (STEC) are excreted in feces and persist in the environment until they die or recolonize a new host. Surface waters contaminated with manure-borne STEC can infect humans through drinking and recreational water use or irrigated crops that are minimally cooked. In this study, manure-impacted water microcosms mimicking beef cattle feedlot …


Reducing Dissolved Phosphorus In Stream Water May Not Influence Estimation Of Sediment Equilibrium Phosphorus Concentrations, Eleanor Henson May 2020

Reducing Dissolved Phosphorus In Stream Water May Not Influence Estimation Of Sediment Equilibrium Phosphorus Concentrations, Eleanor Henson

Biological and Agricultural Engineering Undergraduate Honors Theses

The potential for stream sediments to adsorb or release phosphorus (P) depends on the equilibrium P concentration (EPC), which is the water column P concentration where P is neither (net) adsorbed nor released from the sediments. Current methods of measuring EPC in streams include adding known P concentrations to stream water, mixing with fresh sediments, and allowing the mixture to reach equilibrium through P sorption. Sediment EPC is usually calculated as the x-intercept of the linear relationship between initial P concentrations and P absorbed by the sediments. However, the x-intercept is often an extrapolation past the known data set (i.e. …


Accumulation And Release Of Nutrients By Immersed Stalks Collected On Selected Dates Following Harvest, John E. Gilley, David B. Marx Jan 2020

Accumulation And Release Of Nutrients By Immersed Stalks Collected On Selected Dates Following Harvest, John E. Gilley, David B. Marx

Biological Systems Engineering: Papers and Publications

The concentrations of phosphorus (P) and nitrogen (N) in runoff from cropland areas may be influenced by accumulation and release of P and N by stalk residues. A laboratory study was conducted to measure the effects of time since harvest and immersion period on accumulation and release of P and N by corn, soybean, and wheat stalks. Experimental variables included type of stalk material (corn, soybean, and wheat), time since harvest (six residue collection dates over an approximate 1-year period), and stalk immersion period (25 s (0.42 min), 250 s (4.2 min), 2500 s (42 min), 25,000 s (6.9 h), …


Influence Of Setback Distance On Antibiotics And Antibiotic Resistance Genes In Runoff And Soil Following The Land Application Of Swine Manure Slurry, Maria C. Hall, Noelle Mware, John E. Gilley, Shannon L. Bartelt-Hunt, Daniel D. Snow, Amy M. Schmidt Schmidt, Kent M. Eskridge, Xu Li Jan 2020

Influence Of Setback Distance On Antibiotics And Antibiotic Resistance Genes In Runoff And Soil Following The Land Application Of Swine Manure Slurry, Maria C. Hall, Noelle Mware, John E. Gilley, Shannon L. Bartelt-Hunt, Daniel D. Snow, Amy M. Schmidt Schmidt, Kent M. Eskridge, Xu Li

Biological Systems Engineering: Papers and Publications

The environmental spread of antibiotics and antibiotic resistance genes (ARGs) from the land application of livestock wastes can be a potential public health threat. The objective of this study was to assess the effects of setback distance, which determines how close manure may be applied in relation to surface water, on the transport of antibiotics and ARGs in runoff and soil following land application of swine manure slurry. Rainfall simulation tests were conducted on field plots covered with wheat residues, each of which contained an upslope manure region where slurry was applied and an adjacent downslope setback region that did …


Swine Slurry Characteristics As Affected By Selected Additives And Disinfectants, Jon Duerschner, Shannon L. Bartelt-Hunt, Kent Eskridge, John E. Gilley, Xu Li, Amy M. Schmidt, Daniel D. Snow Jan 2020

Swine Slurry Characteristics As Affected By Selected Additives And Disinfectants, Jon Duerschner, Shannon L. Bartelt-Hunt, Kent Eskridge, John E. Gilley, Xu Li, Amy M. Schmidt, Daniel D. Snow

Biological Systems Engineering: Papers and Publications

Current swine industry practice is to house animals in confinement facilities which capture and store feces and urine as slurry in pits below the production area. Additives and disinfectants may be introduced into the manure pits. This study was conducted to measure the effects of additives and disinfectants on temporal changes in swine slurry characteristics. Slurry from a commercial swine production facility in southeast Nebraska, USA was collected and transferred to 57 L reactors located within a greenhouse. Selected additives and disinfectants were added to the reactors and physical properties, chemical characteristics, and antibiotic concentrations were monitored for 40 days. …


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 and …


Rating Curve Development For The Upper James Fork, Lower James Fork And Hinkle Jones Creek In The Upper Poteau River Watershed In Arkansas, Meagan O'Hare May 2019

Rating Curve Development For The Upper James Fork, Lower James Fork And Hinkle Jones Creek In The Upper Poteau River Watershed In Arkansas, Meagan O'Hare

Biological and Agricultural Engineering Undergraduate Honors Theses

Stream discharge is necessary to estimate loads and calibrate and validate watershed models. Access to long-term water quality data and discharge measurements allows for modeling of water quality changes across a watershed over time. However, discharge monitoring stations are often expensive to install and maintain, particularly in small rivers. A more cost-effective method for monitoring streamflow has been implemented in the Upper Poteau River Watershed (UPRW) in Arkansas. This method consists of an SonTek acoustic doppler instrument for measuring storm stream flow, with is combined with manual baseflow discharge measurements. The combined stormflow and baseflow measurements are combined with a …


Edge-Of-Field Hydrology And Nutrient Fluxes Within Northeastern Agroecosystems: Evaluation Of Alternative Management Practices And Water Quality Models, Cameron Robert Twombly Jan 2019

Edge-Of-Field Hydrology And Nutrient Fluxes Within Northeastern Agroecosystems: Evaluation Of Alternative Management Practices And Water Quality Models, Cameron Robert Twombly

Graduate College Dissertations and Theses

Agricultural runoff is one of largest contributors of phosphorus (P), nitrogen (N), and sediment affecting freshwater systems in watersheds across the Northeastern U.S., including the Lake Champlain Basin in Vermont. Agricultural cropping systems, such as corn silage and haylands, used for dairy feed production have been shown to impact watershed hydrology and water quality. Agricultural best management practices (BMPs) have the potential to decrease runoff volumes and flow rates and the associated export of nutrients and sediment from agricultural fields. Many states in the Northeastern U.S., including Vermont, are beginning to require farmers to implement water quality BMPs and further …


Variability Of E. Coli In Streambed Sediments And Its Implication For Water Quality, Sadia Salam Jan 2019

Variability Of E. Coli In Streambed Sediments And Its Implication For Water Quality, Sadia Salam

Electronic Theses and Dissertations

Fecal indicator bacteria (FIB), including E. coli, are the number one cause of water quality impairments in the United States according to the USEPA. FIB are used as a predictor to identify the possible presence of pathogens in waterbodies. E. coli is a useful indicator of gastrointestinal (GI) related illnesses from contact with fresh water. While surface water is routinely monitored for water quality, streambed sediments are rarely considered as a source of FIB to the overlying water column. This study focuses on understanding the variation of E. coli concentrations in streambed sediments and the potential impact of sediment sources …


Setback Distance Requirements For Removal Of Swine Slurry Constituents In Runoff, John E. Gilley, Shannon L. Bartelt-Hunt, Kent M. Eskridge, Xu Li, Amy M. Schmidt, Daniel D. Snow Dec 2017

Setback Distance Requirements For Removal Of Swine Slurry Constituents In Runoff, John E. Gilley, Shannon L. Bartelt-Hunt, Kent M. Eskridge, Xu Li, Amy M. Schmidt, Daniel D. Snow

Biological Systems Engineering: Papers and Publications

The use of setback distances for manure application on cropland areas adjacent to surface water bodies could serve a function similar to vegetative filter strips. However, little information currently exists to identify the setback distances necessary to effectively reduce the transport of contaminants in runoff. The objective of this study was to determine the effects of setback distance and runoff rate on concentrations of selected constituents in runoff following land application of swine slurry to a no-till cropland area in southeast Nebraska. The study site had a residue cover of 7.73 Mg ha-1 and a slope gradient of 4.9%. The …


Evaluation Of Woodchip Bioreactors And Phosphorus Adsorption Media For Nutrient Removal From Subsurface Drainage Water, Utsav Thapa Jan 2017

Evaluation Of Woodchip Bioreactors And Phosphorus Adsorption Media For Nutrient Removal From Subsurface Drainage Water, Utsav Thapa

Electronic Theses and Dissertations

Increased subsurface drainage over the past few decades in eastern South Dakota contributed to agricultural water quality problems. Nutrient losses, primarily nitrate-N and dissolved P, from subsurface drainage, have been identified as major contributors to eutrophication in the Great Lakes and Gulf of Mexico. Denitrifying bioreactors and P adsorption structures are edge-of field practices that can be used to protect water quality in waters downstream of subsurface drainage systems. The objectives of this study were to evaluate the effectiveness of woodchip bioreactors and a P adsorption structure in removing nitrate-N and dissolved P from subsurface drainage water. Four woodchip bioreactors …


Runoff Water Quality Characteristics Following Swine Slurry Application Under Broadcast And Injected Conditions, Nicole R. Schuster, Shannon L. Bartelt-Hunt, Lisa M. Durso, John E. Gilley, Xu Li, David B. Marx, Amy M. Schmidt, Daniel D. Snow Jan 2017

Runoff Water Quality Characteristics Following Swine Slurry Application Under Broadcast And Injected Conditions, Nicole R. Schuster, Shannon L. Bartelt-Hunt, Lisa M. Durso, John E. Gilley, Xu Li, David B. Marx, Amy M. Schmidt, Daniel D. Snow

Biological Systems Engineering: Papers and Publications

This study was conducted to measure the effects of swine slurry application method, time following slurry application, and runoff rate on selected water quality characteristics. Slurry from a commercial swine operation was broadcast or injected on field plots at a rate required to meet annual nitrogen requirements for corn. Rainfall simulation tests were conducted at five varying periods following slurry application. During each study period, three simulated rainfall events, separated by 24 h intervals, were applied for 30 min duration at an intensity of approximately 70 mm h-1. Following the third rainfall simulation event, inflow was applied at …


Wetlands And Coastal Systems: Protecting And Restoring Valuable Ecosystems, C. T. Agouridis, K. R. Douglas-Mankin, A. C. Linhoss, A. R. Mittelstet Sep 2016

Wetlands And Coastal Systems: Protecting And Restoring Valuable Ecosystems, C. T. Agouridis, K. R. Douglas-Mankin, A. C. Linhoss, A. R. Mittelstet

Biological Systems Engineering: Papers and Publications

Wetlands and coastal systems are unique, highly productive, and often threatened landscapes that provide a host of services to both humans and the environment. This article introduces a five-article Wetlands and Coastal Systems Special Collection that evolved from a featured session at the 2015 ASABE Annual International Meeting in New Orleans, Louisiana. The Collection provides perspectives on tools and techniques for enhancing the protection and restoration of wetlands and coastal systems with emphasis on vegetation, hydrology, water quality, and planning. Topics span the Florida Everglades (two articles) and Virginia floodplain (one article) wetland systems and include remote sensing (one article) …


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 swine …


Effect Of Bioenergy Crops And Fast Growing Trees On Hydrology And Water Quality In The Little Vermilion River Watershed, Tian Guo Apr 2016

Effect Of Bioenergy Crops And Fast Growing Trees On Hydrology And Water Quality In The Little Vermilion River Watershed, Tian Guo

Open Access Dissertations

Energy security and sustainability require a suite of biomass crops, including woody species. Short rotation woody crops (SRWCs) such as Populus have great potential as biofuel feedstocks. Quantifying biomass yields of bioenergy crop and hydrologic and water quality responses to growth is important should it be widely planted in the Midwestern U.S. Subsurface tile drainage systems enable the Midwest area to become highly productive agricultural lands, but also create environmental problems like nitrate-N contamination of the water it drains. The Soil and Water Assessment Tool (SWAT) has been used to model watersheds with tile drainage, but the new tile drainage …


Long-Term Effects Of Forestry Best Management Practices On Hydrology And Water Chemistry In Three Appalchian Headwater Catchments, Kameryn I. Wright Jan 2016

Long-Term Effects Of Forestry Best Management Practices On Hydrology And Water Chemistry In Three Appalchian Headwater Catchments, Kameryn I. Wright

Theses and Dissertations--Biosystems and Agricultural Engineering

In 1982, a study was initiated in the Field Branch watershed, in the University of Kentucky’s Robinson Forest, to evaluate forestry best management practice (BMP) effectiveness after intensive harvesting. The study utilized a paired watershed approach on three adjacent Field Branch subcatchments. One subcatchment was left as the control, one had BMPs implemented (including a 50-ft undisturbed buffer along the stream), and one was clear-cut to the stream’s banks without the use of BMPs (i.e. logger’s choice). Prior research has shown that logging can negatively impact watershed functions by altering stream hydrology, geomorphology, water quality, and instream habitat. Thus, the …


Removal Of Cattle Manure Constituents In Runoff From No-Till Cropland As Affected By Setback Distance, John E. Gilley, Aaron J. Sindelar, Brian L. Woodbury Jan 2016

Removal Of Cattle Manure Constituents In Runoff From No-Till Cropland As Affected By Setback Distance, John E. Gilley, Aaron J. Sindelar, Brian L. Woodbury

Biological Systems Engineering: Papers and Publications

Vegetative filter strips located at the bottom of a hillslope have been shown to substantially reduce nutrients and sediment in runoff. Cropland areas could serve a similar function. However, little scientifically derived information is available to help identify the setback distances required to effectively reduce the transport of contaminants in runoff. The objective of this study was to determine the effects of setback distance and runoff rate on the concentrations and mass transport rates of selected constituents following land application of beef cattle manure to a no-till cropland area. The study site had a residue cover of 8.84 Mg ha-1 …


Wetlands And Coastal Systems: Protecting And Restoring Valuable Ecosystems, Carmen T. Agouridis, Kyle R. Douglas-Mankin, Anna C. Linhoss, Aaron R. Mittelstet Jan 2016

Wetlands And Coastal Systems: Protecting And Restoring Valuable Ecosystems, Carmen T. Agouridis, Kyle R. Douglas-Mankin, Anna C. Linhoss, Aaron R. Mittelstet

Biosystems and Agricultural Engineering Faculty Publications

Wetlands and coastal systems are unique, highly productive, and often threatened landscapes that provide a host of services to both humans and the environment. This article introduces a five-article Wetlands and Coastal Systems Special Collection that evolved from a featured session at the 2015 ASABE Annual International Meeting in New Orleans, Louisiana. The Collection provides perspectives on tools and techniques for enhancing the protection and restoration of wetlands and coastal systems with emphasis on vegetation, hydrology, water quality, and planning. Topics span the Florida Everglades (two articles) and Virginia floodplain (one article) wetland systems and include remote sensing (one article) …


Removal Of Cattle Manure Constituents In Runoff From No-Till Cropland As Affected By Setback Distance, John E. Gilley, Aaron J. Sindelar, Bryan L. Woodbury Jan 2016

Removal Of Cattle Manure Constituents In Runoff From No-Till Cropland As Affected By Setback Distance, John E. Gilley, Aaron J. Sindelar, Bryan L. Woodbury

Biological Systems Engineering: Papers and Publications

Vegetative filter strips located at the bottom of a hillslope have been shown to substantially reduce nutrients and sediment in runoff. Cropland areas could serve a similar function. However, little scientifically derived information is available to help identify the setback distances required to effectively reduce the transport of contaminants in runoff. The objective of this study was to determine the effects of setback distance and runoff rate on the concentrations and mass transport rates of selected constituents following land application of beef cattle manure to a no-till cropland area. The study site had a residue cover of 8.84 Mg ha …


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 of 44 observations, …


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 corn (SC) on the flow …


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 ha–1 to chisel plow and no–till corn plots, …


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 effluent …


Estimating The Water Quality Condition Of River And Lake Water In The Midwestern United States From Its Spectral Characteristics, Jing Tan Dec 2015

Estimating The Water Quality Condition Of River And Lake Water In The Midwestern United States From Its Spectral Characteristics, Jing Tan

Open Access Dissertations

This study focuses on developing/calibrating remote sensing algorithms for water quality retrieval in Midwestern rivers and lakes. In the first part of this study, the spectral measurements collected using a hand-held spectrometer as well as water quality observations for the Wabash River and its tributary the Tippecanoe River in Indiana were used to develop empirical models for the retrieval of chlorophyll (chl) and total suspended solids (TSS). A method for removing sky and sun glint from field spectra for turbid inland waters was developed and tested. Empirical models were then developed using a subset of the field measurements with the …


Effect Of Soil Sampling Density And Landscape Features On Soil Test Phosphorus, Donald J. Stamper, Carmen T. Agouridis, Dwayne R. Edwards, Mark A. Purschwitz Sep 2014

Effect Of Soil Sampling Density And Landscape Features On Soil Test Phosphorus, Donald J. Stamper, Carmen T. Agouridis, Dwayne R. Edwards, Mark A. Purschwitz

Biosystems and Agricultural Engineering Faculty Publications

Organic and/or inorganic fertilizers are used to promote crop growth yet the rate of fertilizer application is often based on the nitrogen needs of the crop and not the phosphorus needs, especially when utilizing animal manures with low N-to-P ratios as compared to plant N:P uptake. Because of this, soil phosphorus levels in many areas of the world are in excess of crop needs. Excessive levels of phosphorus in water bodies such as streams and lakes can result in a condition known as eutrophication. With eutrophication, nutrients promote algal growth which in turn decreases dissolved oxygen levels in receiving water …


Water Quality Effects Of Cellulosic Biofuel Crops Grown On Marginal Land, Ruoyu Wang Jul 2014

Water Quality Effects Of Cellulosic Biofuel Crops Grown On Marginal Land, Ruoyu Wang

Ruoyu Wang

Since Congress' Energy Independence and Security Act of 2007, there has been increasing interest
in the ability to reach the cellulosic renewable fuel goal of 60.5 billion liters. Cellulosic biofuel crops include
sorghum, switchgrass, Miscanthus, woody crops, and crop residue, among others. Because of concern about
food production on existing highly productive agricultural lands, there is an interest regarding biofuel crop
production on marginal lands. Second generation biofuels, such as perennial grasses and woody plants,
provide an alternative to traditional crops; however, their effects on water quality are not well studied when
grown on marginal lands. Because grasses and woody …


Responses Of Hydrological Processes And Water Quality To Land Use/Cover (Lulc) And Climate Change In A Coastal Watershed, Ruoyu Wang Jan 2014

Responses Of Hydrological Processes And Water Quality To Land Use/Cover (Lulc) And Climate Change In A Coastal Watershed, Ruoyu Wang

Ruoyu Wang

Land use/cover (LULC) and climate change are two main factors affecting watershed hydrology and, in turn, influencing water quality. In this paper, the potential changes in flow, Total Suspended Solid (TSS) and nutrient (nitrogen and phosphorous) loadings were investigated under climate, LULC and combined change scenarios in the Wolf Bay watershed in coastal Alabama, USA. Four Global Circulation Models (GCMs) under three Special Report Emission Scenarios (SRES) of greenhouse gas were used to demonstrate the future climate change (2016-2040). Three projected LULC maps (2030) were employed to reflect different extents of urbanization in future. The individual, combined and synergistic impacts …


Nutrient Concentrations Of Runoff As Affected By The Diameter Of Unconsolidated Material From Feedlot Surfaces, John E. Gilley, Gregory Boone, David B. Marx Jan 2014

Nutrient Concentrations Of Runoff As Affected By The Diameter Of Unconsolidated Material From Feedlot Surfaces, John E. Gilley, Gregory Boone, David B. Marx

Biological Systems Engineering: Papers and Publications

Beef cattle feedlots contain unconsolidated material that accumulates on the feedlot surface during a feeding cycle. This study was conducted to measure the effects of varying diameters of unconsolidated surface material and varying flow rates on nutrient concentrations in runoff. Unconsolidated surface material with an average diameter of 4.76, 9.53, 19.1, or 47.5 mm and a composite sample with a 15.2 mm mean diameter were placed within 0.75 m wide × 4.0 m long plot areas. Flow was then introduced at the top of the plots in successive increments, and runoff samples for water quality analyses were obtained. Particle diameter …