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Articles 301 - 330 of 365

Full-Text Articles in Bioresource and Agricultural Engineering

Light Backscatter Of Milk Products For Transition Sensing Using Optical Fibers, Frederick A. Payne, Czarena L. Crofcheck, Sue E. Nokes, Klat C. Kang Nov 1999

Light Backscatter Of Milk Products For Transition Sensing Using Optical Fibers, Frederick A. Payne, Czarena L. Crofcheck, Sue E. Nokes, Klat C. Kang

Biosystems and Agricultural Engineering Faculty Publications

Transition sensors are needed, particularly in the dairy industry, for detecting transitions in pipe flow systems from product-to-water or product-to-product (such as from chocolate to vanilla ice cream mix). Transition information is used to automatically sequence valves to minimize product waste. Optical fibers were used to measure light backscatter between 400 and 950 nm as a function of milk concentration in water and milkfat concentration in milk. The normalized response (100% for product and 0% for water) as a function of product concentration in water was approximately logarithmic for skim milk between 400 and 900 nm and approximately linear for …


Runoff From Fescue Plots Treated With Trimec, Cristopher G. Moss, Dwayne R. Edwards, Stephen R. Workman, R. Michael Williams Nov 1999

Runoff From Fescue Plots Treated With Trimec, Cristopher G. Moss, Dwayne R. Edwards, Stephen R. Workman, R. Michael Williams

Biosystems and Agricultural Engineering Faculty Publications

Runoff of herbicides can promote adverse impacts in receiving waters. The objective of this study was to assess the effects of rainfall delay, herbicide application rate, rainfall intensity, and pre-application rainfall on runoff of TRIMEC (a combination of 2,4-D, dicamba, and mecoprop), a herbicide that is commonly used in central Kentucky. The levels of rainfall delay were 0, 2, and 4 d following application; and the levels of herbicide application rate were 0, 0.5, 1 and 2 times the recommended rate. Simulated rainfall was applied at intensities of 64, 102, and 140 mm h-1; and the depths of …


Modeling Surface And Subsurface Pesticide Transport Under Three Field Conditions Using Przm-3 And Gleams, Robert W. Malone, Richard C. Warner, Stephen R. Workman, Matt E. Byers Sep 1999

Modeling Surface And Subsurface Pesticide Transport Under Three Field Conditions Using Przm-3 And Gleams, Robert W. Malone, Richard C. Warner, Stephen R. Workman, Matt E. Byers

Biosystems and Agricultural Engineering Faculty Publications

Contaminant transport models should be evaluated over a wide range of conditions to determine their limitations. The models PRZM and GLEAMS have been evaluated many times, but few studies are available in which predicted movement in runoff and percolate were simultaneously evaluated against field data. Studies of this type are essential because pesticide leaching and runoff are mutually dependent processes. For this reason, PRZM-3 and GLEAMS were evaluated for their ability to predict metribuzin concentrations in runoff, sediment, subsurface soil, and pan lysimeters under three field conditions (yard waste compost amended, no-till, and conventional-till) on a Lowell silt loam soil. …


Comparison Of Water And Temperature Distribution Profiles Under Sand Tube Irrigation, Masoud Meshkat, Richard C. Warner, Stephen R. Workman Nov 1998

Comparison Of Water And Temperature Distribution Profiles Under Sand Tube Irrigation, Masoud Meshkat, Richard C. Warner, Stephen R. Workman

Biosystems and Agricultural Engineering Faculty Publications

Drip irrigation is one of the most efficient systems in delivering water to the plant root zone. Research has shown that the saturated, or nearly saturated, surface beneath the emitter may increase evaporation thereby reducing the irrigation efficiency. To increase the efficiency of surface applied drip irrigation on permanent tree crops a sand tube irrigation (STI) method was developed and tested. The sand tube method consists of removing a soil core beneath the emitter and filling the void with coarse sand. A weighing lysimeter was designed and instrumented to directly measure temporal evaporation during irrigation and for a period of …


Vegetated Filter Strip Removal Of Cattle Manure Constituents In Runoff, Teng T. Lim, Dwayne R. Edwards, Stephen R. Workman, Brian T. Larson, Lloyd Dunn Sep 1998

Vegetated Filter Strip Removal Of Cattle Manure Constituents In Runoff, Teng T. Lim, Dwayne R. Edwards, Stephen R. Workman, Brian T. Larson, Lloyd Dunn

Biosystems and Agricultural Engineering Faculty Publications

Pasture runoff can contribute to elevated concentrations of nutrients, solids, and bacteria in downstream waters. The objective of this study was to determine the effects of vegetative filter strip (VFS) length on concentrations and transport of nitrogen, phosphorus, solids and fecal coliform in runoff from plots treated with cattle manure. Three plots with dimensions of 2.4 × 30.5 m were used. The upper 12.2 m of each plot was treated with cattle manure, while the lower 18.3 m acted as a VFS. Runoff produced by rainfall simulators was sampled at VFS lengths of 0, 6.1, 12.2, and 18.3 m and …


Response Of Runoff Diazinon Concentration To Formulation And Post-Application Irrigation, Joshua R. Evans, Dwayne R. Edwards, Stephen R. Workman, R. Michael Williams Sep 1998

Response Of Runoff Diazinon Concentration To Formulation And Post-Application Irrigation, Joshua R. Evans, Dwayne R. Edwards, Stephen R. Workman, R. Michael Williams

Biosystems and Agricultural Engineering Faculty Publications

Pesticides used in urban environments can be transported in runoff to downstream waters and cause adverse environmental consequences. This experiment assessed the effects of post-application irrigation depth (0, 6.4, and 12.7 mm) and formulation (liquid and granular) on concentration and transport of diazinon (a pesticide commonly used for lawn insect control) in runoff from “tall” fescue (Festuca arundinacea Schreb.) plots. The post-application irrigation was applied using rainfall simulators immediately following diazinon application. The rainfall simulators were again used approximately 2 h after diazinon application to apply the equivalent of a heavy rainfall (64 mm/h for approximately 1.5 h) to generate …


Comparison Of Observed And Simulated Grow-Finish Swine Performance Under Summer Conditions, Larry W. Turner, Thomas C. Bridges, Richard D. Coffey, Richard S. Gates, Gary R. Parker, Tami M. Brown-Brandl, Douglas G. Overhults Jul 1998

Comparison Of Observed And Simulated Grow-Finish Swine Performance Under Summer Conditions, Larry W. Turner, Thomas C. Bridges, Richard D. Coffey, Richard S. Gates, Gary R. Parker, Tami M. Brown-Brandl, Douglas G. Overhults

Biosystems and Agricultural Engineering Faculty Publications

As a part of a National Pork Producers Council educational program, our research and extension team at the University of Kentucky was linked with an independent commercial swine producer to test the NCPIG model against observed commercial on-farm data. This experience provided improved information for model development as well as increased producer insight into the data input needs and potential benefits of modeling. Detailed production information comparisons between the NCPIG model and producer data are presented for summer time conditions to assess the validity of the NCPIG model for simulation of grow-finish swine performance. Results demonstrated that the NCPIG model …


Quality Of Runoff From Plots Treated With Municipal Sludge And Horse Bedding, Elizabeth L. Busheé, Dwayne R. Edwards, Philip A. Moore Jr. Jul 1998

Quality Of Runoff From Plots Treated With Municipal Sludge And Horse Bedding, Elizabeth L. Busheé, Dwayne R. Edwards, Philip A. Moore Jr.

Biosystems and Agricultural Engineering Faculty Publications

Land application of horse stall bedding and municipal sludge can increase runoff concentrations of nutrients, organic matter, and bacteria as well as steroidal hormones such as estrogen. Concentrations of materials in runoff from sites treated with animal manure can be reduced by aluminum sulfate, or alum [Al2(SO4)3•14H2O] treatment. The objectives of this study were to assess plots treated with horse stall bedding or municipal sludge for: (a) runoff quality [concentrations of nitrate nitrogen (NO3-N), ammonia nitrogen (NH3-N), orthophosphate-phosphorus (PO4-P), fecal coliform (FC), chemical oxygen demand (COD) …


Effect Of Parameter Distributions On Uncertainty Analysis Of Hydrologic Models, C. Thomas Haan, Daniel E. Storm, T. Al-Issa, Sandeep Prabhu, George J. Sabbagh, Dwayne R. Edwards Jan 1998

Effect Of Parameter Distributions On Uncertainty Analysis Of Hydrologic Models, C. Thomas Haan, Daniel E. Storm, T. Al-Issa, Sandeep Prabhu, George J. Sabbagh, Dwayne R. Edwards

Biosystems and Agricultural Engineering Faculty Publications

Increasing concern about the accuracy of hydrologic and water quality models has prompted interest in procedures for evaluating the uncertainty associated with these models. If a Monte Carlo simulation is used in an uncertainty analysis, assumptions must be made relative to the probability distributions to assign to the model input parameters. Some have indicated that since these parameters can not be readily determined, uncertainty analysis is of limited value. In this article we have evaluated the impact of parameter distribution assumptions on estimates of model output uncertainty. We conclude that good estimates of the means and variances of the input …


Validating A Vegetative Filter Strip Performance Model, Puneet Srivastava, Thomas A. Costello, Dwayne R. Edwards, James A. Ferguson Jan 1998

Validating A Vegetative Filter Strip Performance Model, Puneet Srivastava, Thomas A. Costello, Dwayne R. Edwards, James A. Ferguson

Biosystems and Agricultural Engineering Faculty Publications

Vegetative filter strips (VFS) reduce losses of nutrients, solids, and other materials from land area treated with fertilizers and manures. A number of models are available that simulate nutrient and sediment transport in VFS. While VFS effectiveness is considered to depend on lengths of pollutant source area and VFS areas, few published studies have tried to validate these models using variable pollutant source area and VFS area. The objective of this study was to validate an event-based nutrient transport model (Chaubey et al., 1995) that simulates soluble nutrient transport in VFS. This model links three sub-models: modified Green-Ampt infiltration, non-linear …


Effect Of Bmp Implementation On Storm Flow Quality Of Two Northwestern Arkansas Streams, Dwayne R. Edwards, Tommy C. Daniel, H. Don Scott, Phillip A. Moore Jr., John F. Murdoch, Paul F. Vendrell Sep 1997

Effect Of Bmp Implementation On Storm Flow Quality Of Two Northwestern Arkansas Streams, Dwayne R. Edwards, Tommy C. Daniel, H. Don Scott, Phillip A. Moore Jr., John F. Murdoch, Paul F. Vendrell

Biosystems and Agricultural Engineering Faculty Publications

The effectiveness of management practices in improving quality of runoff from agricultural land areas has been reported based primarily on results from plot- and field-scale studies. There is limited information available on watershed scales, particularly when the dominant agricultural land use is pasture. The objective of this study was to determine whether a program of Best Management Practice (BMP) implementation in the Lincoln Lake watershed of northwestern Arkansas was effective in reducing storm stream flow concentrations and mass transport of nitrate nitrogen (NO3-N), ammonia nitrogen (NH3-N), total Kjeldahl nitrogen (TKN), ortho-phosphorus (PO4-P), total phosphorus …


Indicator Bacteria Concentrations Of Two Northwest Arkansas Streams In Relation To Flow And Season, Dwayne R. Edwards, Mark S. Coyne, Tommy C. Daniel, P. F. Vendrell, J. F. Murdoch, P. A. Moore Jr. Jan 1997

Indicator Bacteria Concentrations Of Two Northwest Arkansas Streams In Relation To Flow And Season, Dwayne R. Edwards, Mark S. Coyne, Tommy C. Daniel, P. F. Vendrell, J. F. Murdoch, P. A. Moore Jr.

Biosystems and Agricultural Engineering Faculty Publications

Concentrations of indicator bacteria such as fecal coliform (FC) and fecal streptococcus (FS) are often used to assess the suitability of waters for their intended use(s) and to allocate resources for water quality improvement measures. There is evidence, however, that concentrations of FC and FS can be influenced by variables such as season and flow rate during sampling, which could lead to biased results. The objective of this study was to assess the impacts of season and flow rate on concentrations of FC and FS. Fecal indicator bacteria concentrations were measured for approximately three years at five sites on two …


Runoff Quality Responses To Cattle-Gazing Strategy And Grassed Buffer Zone Length, Dwayne R. Edwards, Brian T. Larsen, Teng T. Lim Jan 1997

Runoff Quality Responses To Cattle-Gazing Strategy And Grassed Buffer Zone Length, Dwayne R. Edwards, Brian T. Larsen, Teng T. Lim

KWRRI Research Reports

Grazed pastures represent a source of potential nonpoint pollution. In comparison to other nonpoint sources (e.g., row-cropped lands), relatively little information exists regarding possible magnitudes of pollution from grazed pasture; how that pollution is affected by weather, soil, management and other variables; and how the pollution can be minimized. The objective of this study was to assess how the quality of runoff from simulated grazed pasture is influenced by grazing duration (4-12 weeks), grazing strategy (no grazing, conventional grazing and rotational grazing), and by the use of grassed buffer strips (ranging in length from O to 18.3 m) installed down-slope …


Vegetative Filter Strip Removal Of Metals In Runoff From Poultry Litter-Amended Fescuegrass Plots, Dwayne R. Edwards, P. A. Moore Jr., Tommy C. Daniel, Puneet Srivastava, D. J. Nichols Jan 1997

Vegetative Filter Strip Removal Of Metals In Runoff From Poultry Litter-Amended Fescuegrass Plots, Dwayne R. Edwards, P. A. Moore Jr., Tommy C. Daniel, Puneet Srivastava, D. J. Nichols

Biosystems and Agricultural Engineering Faculty Publications

Runoff from land areas amended with poultry (Gallus gallus domesticus) manure can contain elevated concentrations of metals such as Cu, Fe, and Zn. Vegetative filter strips (VFS) can reduce runoff concentrations of animal manure components, but reported studies have typically focused on nutrients and solids rather than metals. This experiment assessed the impact of VFS length (0 to 12 m) on concentrations and mass losses of Cu, Fe, K, Na, Ni, and Zn in runoff from fescuegrass (Festuca arundinacea Schreb.) plots (1.5 m wide × 6 and 12 m long) treated with poultry litter. The runoff was produced from simulated …


Evaluation Of The Crop Growth Component Of The Root Zone Water Quality Model For Corn In Ohio, Sue E. Nokes, Feliks M. Landa, Jon D. Hanson Jan 1996

Evaluation Of The Crop Growth Component Of The Root Zone Water Quality Model For Corn In Ohio, Sue E. Nokes, Feliks M. Landa, Jon D. Hanson

Biosystems and Agricultural Engineering Faculty Publications

The Root Zone Water Quality Model (RZWQM) is a computer model developed to simulate water, chemical, and biological processes in the root zone of agricultural management systems. As of this writing RZWQM is in the beta-testing phase of development. This article reports on a parameterization and evaluation study performed in Ohio on field corn for the crop growth component of RZWQM. The generic crop growth model in RZWQM had not previously been parameterized or tested on field corn. This article reports the results of such a study. One year of data was used to calibrate RZWQM, and two additional years …


Comparison Of Daily Water Table Depth Prediction By Four Simulation Models, Eric D. Desmond, Andrew D. Ward, Norman R. Fausey, Stephen R. Workman Jan 1996

Comparison Of Daily Water Table Depth Prediction By Four Simulation Models, Eric D. Desmond, Andrew D. Ward, Norman R. Fausey, Stephen R. Workman

Biosystems and Agricultural Engineering Faculty Publications

The Agricultural Drainage And Pesticide Transport (ADAPT) model was compared to the water management simulation models DRAINMOD, SWATREN, and PREFLO. SWATREN and PREFLO are one-dimensional finite-difference models while ADAPT and DRAINMOD are one-dimensional mass balance models. ADAPT, an extension of the computer model GLEAMS, also provides chemical transport information. All four models were tested against field data from Aurora, North Carolina. Observed water table depth data were collected during 1973 through 1977 from a water table management field experiment with three subsurface drain spacing treatments of 7.5, 15, and 30 m.

Both the standard error of estimate and the average …


Performance Of Vegetative Filter Strips With Varying Pollutant Source And Filter Strip Lengths, Puneet Srivastava, Dwayne R. Edwards, Tommy C. Daniel, Philip A. Moore Jr., Thomas A. Costello Jan 1996

Performance Of Vegetative Filter Strips With Varying Pollutant Source And Filter Strip Lengths, Puneet Srivastava, Dwayne R. Edwards, Tommy C. Daniel, Philip A. Moore Jr., Thomas A. Costello

Biosystems and Agricultural Engineering Faculty Publications

Vegetative filter strips (VFS) can reduce runoff losses of pollutants such as nitrogen (N) and phosphorus (P) from land areas treated with fertilizers. While VFS effectiveness is considered to depend on lengths of pollutant source and VFS areas, there is little experimental evidence of this dependence, particularly when the pollutant source is manure-treated pasture. This study assessed the effects of pollutant source area (fescue pasture treated with poultry litter) length and VFS (fescue pasture) length on VFS removal of nitrate N (NO3-N), ammonia N (NH3-N), total Kjeldahl N (TKN), ortho-P (PO4-P), total P (TP), …


Minimum Ventilation For Modern Broiler Facilities, Richard S. Gates, Douglas G. Overhults, Shuhui H. Zhang Jan 1996

Minimum Ventilation For Modern Broiler Facilities, Richard S. Gates, Douglas G. Overhults, Shuhui H. Zhang

Biosystems and Agricultural Engineering Faculty Publications

New functions for whole-house broiler heat production as a function of bird age using modern straight run broiler growth rates are presented and compared to values in the literature. The approximations are based on field measurements of environmental conditions in modern broiler housing, using a technique that matches predicted to actual fuel use to estimate partitioning between latent and sensible heat. Development of a program utilizing these approximations to compute ventilation and heating requirements for temperature and humidity control in broiler housing is described. The program utilizes steady-state heat and moisture balances commonly used for design purposes, with hourly or …


Vegetative Filter Strip Design For Grassed Areas Treated With Animal Manures, Dwayne R. Edwards, Tommy C. Daniel, Philip A. Moore Jr. Jan 1996

Vegetative Filter Strip Design For Grassed Areas Treated With Animal Manures, Dwayne R. Edwards, Tommy C. Daniel, Philip A. Moore Jr.

Biosystems and Agricultural Engineering Faculty Publications

Vegetative filter strips (VFS) are a low-cost management option that have been demonstrated to be effective in reducing runoff transport of fertilizer constituents applied to grassed areas (pasture or meadow). Runoff quality studies involving fertilizers applied to grassed areas suggest that VFS can be designed by assuming that (1) only infiltration is responsible for pollutant removal, (2) the first post-application runoff event is most important from a water quality perspective (enabling a design event approach), and (3) no pollutant build-up that degrades VFS performance will occur. The purpose of this study was to develop a VFS design algorithm for grassed …


A Direct, Approximate Solution To The Modified Green-Ampt Infiltration Equation, Puneet Srivastava, Thomas A. Costello, Dwayne R. Edwards Jan 1996

A Direct, Approximate Solution To The Modified Green-Ampt Infiltration Equation, Puneet Srivastava, Thomas A. Costello, Dwayne R. Edwards

Biosystems and Agricultural Engineering Faculty Publications

Accurately predicting the rainfall-runoff process is of vital importance for water quality models as well as for correct design of various types of hydraulic structures. This article presents a method of describing the cumulative infiltration process as an explicit function of time using an approximation to the modified Green-Ampt equation given by Mein and Larson (1971). The resulting equation is helpful in predicting cumulative infiltration and therefore infiltration capacity for computer simulation models. The proposed method takes about 50% less time than the usual iterative technique for the same degree of accuracy. The maximum error due to approximation was 1% …


Simulation Of Runoff Transport Of Animal Manure Constituents, Yang Wang, Dwayne R. Edwards, Tommy C. Daniel, H. Don Scott Jan 1996

Simulation Of Runoff Transport Of Animal Manure Constituents, Yang Wang, Dwayne R. Edwards, Tommy C. Daniel, H. Don Scott

Biosystems and Agricultural Engineering Faculty Publications

Runoff losses of land-applied animal manure constituents can adversely affect the quality of downstream waters. Reliable mathematical simulation models can help estimate runoff losses of animal manure constituents and identify management measures to reduce these losses. The objective of this study was to develop and calibrate an event-based simulation model to describe the runoff transport of solids (soil and manure particles) and nutrients (nitrogen and phosphorus) from areas treated with animal manure. The resulting model, consisting of linked hydrology, soil/manure transport, and nutrient transport components, is process-oriented and uses measurable parameters to the greatest degree possible. The three components of …


Quality Of Runoff From Four Northwest Arkansas Pasture Fields Treated With Organic And Inorganic Fertilizer, Dwayne R. Edwards, Tommy C. Daniel, John F. Murdoch, Philip A. Moore Jr. Jan 1996

Quality Of Runoff From Four Northwest Arkansas Pasture Fields Treated With Organic And Inorganic Fertilizer, Dwayne R. Edwards, Tommy C. Daniel, John F. Murdoch, Philip A. Moore Jr.

Biosystems and Agricultural Engineering Faculty Publications

Long-term land application of animal manures, even at agronomic rates, can promote accumulation of soil phosphorus (P) which can, in turn, contribute to increased P loadings to downstream waters. The objective of this study was to assess the soil and runoff effects of replacing animal manure as a soil amendment with inorganic fertilizer (ammonium nitrate, NH4NO3) on fields that had been treated previously with animal manures. Runoff from two pairs of small fields (0.57 to 1.46 ha) was sampled from September 1991 to April 1994. All fields had been treated previously with animal manures; after runoff …


Poultry Litter-Treated Length Effects On Quality Of Runoff From Fescue Plots, Dwayne R. Edwards, Philip A. Moore Jr., Tommy C. Daniel, Puneet Srivastava Jan 1996

Poultry Litter-Treated Length Effects On Quality Of Runoff From Fescue Plots, Dwayne R. Edwards, Philip A. Moore Jr., Tommy C. Daniel, Puneet Srivastava

Biosystems and Agricultural Engineering Faculty Publications

Using experimental data and/or mathematical simulation models to identify practices that reduce pollution from manure-treated areas is sometimes perceived as limited by the unknown validity of extrapolating plot-scale data to larger areas and by uncertainties in modeling transport of various pollutants. The objectives of this study were to assess the effect of length of manure treatment on runoff concentrations of poultry litter constituents and to define the modes of transport (particulate versus soluble) for nitrogen (N), phosphorus (P), carbon (C), and solids. Poultry litter was applied to three 1.5- x 18.3-m fescue (Festuca arundinacea Schreb.) plots with runoff collection …


Application Of Simplified Phosphorus Transport Models To Pasture Fields In Northwest Arkansas, Dwayne R. Edwards, C. T. Haan, Andrew N. Sharpley, John F. Murdoch, Tommy C. Daniel, Philip A. Moore Jr. Jan 1996

Application Of Simplified Phosphorus Transport Models To Pasture Fields In Northwest Arkansas, Dwayne R. Edwards, C. T. Haan, Andrew N. Sharpley, John F. Murdoch, Tommy C. Daniel, Philip A. Moore Jr.

Biosystems and Agricultural Engineering Faculty Publications

Runoff transport of phosphorus (P) is often predicted from simple equations with parameters determined from data applicable primarily to row-cropped and fallow cover conditions. The applicability, accuracy, and precision of such P transport prediction equations under pasture situations are less well defined. The objectives of this study were to determine parameters of simplified runoff P transport equations for pasture fields and to assess the accuracy and precision of the equations. Runoff, sediment yield, soluble P transport, and particulate P transport data were collected from four pasture fields in northwestern Arkansas. Runoff event enrichment ratios and extraction coefficients were computed, and …


Effectiveness Of Vegetative Filter Strips In Controlling Losses Of Surface-Applied Poultry Litter Constituents, Indrajeet Chaubey, Dwayne R. Edwards, Tommy C. Daniel, Philip A. Moore Jr., D. Jeff Nichols Jan 1995

Effectiveness Of Vegetative Filter Strips In Controlling Losses Of Surface-Applied Poultry Litter Constituents, Indrajeet Chaubey, Dwayne R. Edwards, Tommy C. Daniel, Philip A. Moore Jr., D. Jeff Nichols

Biosystems and Agricultural Engineering Faculty Publications

Vegetative filter strips (VFS) have been shown to have high potential for reducing nonpoint source pollution from cultivated agricultural source areas, but information from uncultivated source areas amended with poultry litter is limited. Simulated rainfall was used in analyzing effects of VFS length (0, 3.1, 6.1, 9.2, 15.2, and 21.4 m) on quality of runoff from fescue (Festuca arundinacea Schreb.) plots (1.5 x 24.4 m) amended with poultry litter (5 Mg/ha). The VFS reduced mass transport of ammonia-nitrogen (NH3-N), total Kjeldahl nitrogen (TKN), ortho-phosphorus (PO4-P), total phosphorus (TP), chemical oxygen demand (COD), and total suspended …


Atrazine And Alachlor Dissipation Rates From Field Experiments, Stephen R. Workman, Andrew D. Ward, Norman R. Fausey, Sue E. Nokes Jan 1995

Atrazine And Alachlor Dissipation Rates From Field Experiments, Stephen R. Workman, Andrew D. Ward, Norman R. Fausey, Sue E. Nokes

Biosystems and Agricultural Engineering Faculty Publications

Chemical transport is being monitored in the root zone of three agricultural management systems at the Ohio Management Systems Evaluation Area (OMSEA). Atrazine and alachlor concentration data from soil cores taken to a depth of 0.9 m and partitioned into the increments of 0.0 to 0.15, 0.15 to 0.3, 0.45 to 0.6, and 0.75 to 0.9 m show the herbicides remained in the top 0.15 m of the profile during the 1991 and 1992 growing seasons. The slow movement of herbicides was partly due to below normal rainfall during the period. Since the herbicides have not been transported out of …


Alternative Approaches To On-Farm Research And Technology Exchange, Charles A. Francis, Victoria Mundy, Rhonda Janke, James King Jan 1995

Alternative Approaches To On-Farm Research And Technology Exchange, Charles A. Francis, Victoria Mundy, Rhonda Janke, James King

CARI Extension and Education Materials for Sustainable Agriculture

Decision Case Studies are Ideal for On-Farm Research by R. Kent Crookston (University of Minnesota)

Use of On-Farm Research by Farmers for Technology Development and Transfer by Stewart Wuest, Baird Miller, Stephen Guy, Russ Karow, Rojer Veseth, and Donald Wysocki (Washington State University, University of Idaho, and Oregon State University)

Best Information for Choosing Crop Varieties by Dale Hicks and Robert Stucker (University of Minnesota)

Adaptability Analysis for Diverse Environments by Peter Hildebrand and John Russell (University of Florida and Washington State University)

Complementary Abilities and Objectives in On-Farm Research by Derrick Exner (Iowa State University)

Credibility of On-Farm Research …


Regional Variation In Temperature Humidity Index For Poultry Housing, Richard S. Gates, Hanzhong Zhang, Donald G. Colliver, Douglas G. Overhults Jan 1995

Regional Variation In Temperature Humidity Index For Poultry Housing, Richard S. Gates, Hanzhong Zhang, Donald G. Colliver, Douglas G. Overhults

Biosystems and Agricultural Engineering Faculty Publications

A building thermal model was used to compute hourly values of temperature humidity index (THI) for a broiler house with and without an evaporative misting system. Hourly summer time weather data for 238 U.S.A. locations covering 30 years were used to develop extreme occurrences of THI. Results were incorporated into a Geographical Information System (GIS) database to create isolines of THI and percentage of hours exceeding a heat stress threshold. Regional variations in misting as a suitable cooling technique are presented in terms of hours reduction in annual heat stress. The technique may be used for assisting in management decisions …


Field Calibration Of A Transient Model For Broiler Misting, Richard S. Gates, Douglas G. Overhults, Robert W. Bottcher, Shu Hui Zhang Sep 1992

Field Calibration Of A Transient Model For Broiler Misting, Richard S. Gates, Douglas G. Overhults, Robert W. Bottcher, Shu Hui Zhang

Biosystems and Agricultural Engineering Faculty Publications

A transient model to predict temperature within a tunnel ventilated broiler house during misting is developed. The model is calibrated with field data to obtain steady-state constants; transient predictions are compared to measured temperatures during cyclic misting for two different size birds. Measured temperatures during cyclic misting are shown to swing between steady-state asymptotes predicted from the model. Transient response of the model was faster than measured temperature data, in part due to temperature sensor dynamic response. The model predicts the length-wise temperature profile within the building during misting, and can be used to investigate alternate misting strategies and designs. …


Mechanical Backup Systems For Electronic Environmental Controllers, Richard S. Gates, Douglas G. Overhults, Larry W. Turner Jul 1992

Mechanical Backup Systems For Electronic Environmental Controllers, Richard S. Gates, Douglas G. Overhults, Larry W. Turner

Biosystems and Agricultural Engineering Faculty Publications

A series of mechanical backup systems for electronic environmental controllers is presented for a typical finishing swine barn and a typical tunnel ventilated broiler house. The systems consist of mechanical thermostats and timers used in parallel with the electronic controller, designed to ensure animal survival in the event of controller or related hardware failure. For swine housing, three distinct mechanical backup functions are identified; for broiler housing, four distinct mechanical backup functions are identified. Schematic diagrams of the mechanical backup functions are provided and their implementation is described.