Bioresource and Agricultural Engineering Commons^™

Integration Of An Extended Octagonal Ring Transducer And Soil Coulterometer For Identifying Soil Compaction, Santosh K. Pitla, Larry G. Wells, Scott A. Shearer

Biosystems and Agricultural Engineering Faculty Publications

The soil coulterometer is an "on-the-go" electro-mechanical system which collects impedance force data at multiple depths using an oscillating coulter. During the initial testing (summer 2006), only vertical soil impedance force data was collected using a pressure sensor. To improve the performance of the coulterometer, an extended octagonal ring transducer was integrated into the system to collect both the horizontal and vertical impedance forces given by the soil. In the summer of 2007, data was collected using the revised sensor from a typical central Kentucky field setting in a 0.8-ha (2-acre) plot. Four passes were made with the coulterometer. Seventy …

The Land Is In Your Hands : A Practical Guide For Owners Of Small Rural Landholdings In Western Australia, Department Of Agriculture And Food, Wa

Bulletins 4000 -

This Bulletin discusses various aspects of managing a small farm or property in Western Australia, including soil and land care, vegetation and plant control on farm holdings, water resource management, biosecurity, plant, animal and insect pest control and livestock management.

Crop Yield Response To Precision Deep Tillage, Larry G. Wells, Timothy S. Stombaugh, Scott A. Shearer

Biosystems and Agricultural Engineering Faculty Publications

Experimental precision deep tillage was applied at three sites in central Kentucky with relatively well-drained silt loam soils in no-till crop production. Fields were divided into 0.4 ha (1 ac) grid cells using DGPS mapping. Assessment of soil compaction by machinery traffic was made using multiple soil cone penetrometer measurements and expressed as cone index (CI). Corn, wheat, and soybean yields were depressed in grid cells with CI_avg ≥ 1.5 MPa (218 psi) prior to application of tillage treatments at sites 1 and 3, whereas at site 2, where most of the highest average CI values ranged from 1.44 …

Evaluation Of A Mechanical System For Reconstructing Soil On Surface Mined Land, John P. Fulton, Larry G. Wells

Biosystems and Agricultural Engineering Faculty Publications

The existence of excessive soil compaction has hindered the surface mining industry from returning land to pre−mining productivity after reclamation, especially on prime farmland soils. Heavy earthmoving equipment used during reclamation tends to generate root−limiting bulk densities that adversely affect plant growth thereby decreasing yields. Therefore, the purpose of this study was to evaluate a mechanism, called the ‘Soil Regenerator,’ which reconstructs soil media at minimum bulk density during surface mine reclamation. The prototype soil forming mechanism was mounted on the front of a conventional bulldozer. Soil was placed in long narrow windrows by a scraper or bulldozer. As the …

Mole Drainage For Increased Productivity In The South West Irrigation Area, D L. Bennett, Richard George, Bill Russell

Bulletins 4000 -

Heavy soils, with low rates of soil-water movement, such as those found in the South-West Irrigation Area (SWIA), require closely spaced (2-6 m apart) subsoil drainage systems to provide sufficient water movement to control the effects of salt-waterlogging on pastures. Such close spacing using traditional buried pipe or tile drainage systems is impractical. As a result, mole drainage systems, used in other parts of the world for over 50 years, have gained popularity in the SWIA in recent years.

This Bulletin Farmnote reports the current ‘best-bet’ mole draining technique for SWIA conditions gathered from observations over a number of years …

A Mechanical System For Soil Reconstruction, John Patrick Fulton, Larry G. Wells, Timothy D. Smith

Biosystems and Agricultural Engineering Faculty Publications

One of the most perplexing problems associated with reclaiming surface–mined lands is excessive compaction of soil due to the heavy earthmoving equipment used during the reclamation process. Over the years, some innovative material handling schemes have been devised to limit vehicle traffic during reclamation on reconstructed soil. However, final grading operations can often create root–limiting bulk densities, which affect plant growth and yield. The purpose of this article is to describe a mechanism designed at the University of Kentucky whereby mine soil can be reconstructed without introducing compaction caused by surface traffic in order for the soil to sustain desirable …

A Portable Rainfall Simulator For Plot–Scale Runoff Studies, J. Byron Humphry, Tommy C. Daniel, Dwayne R. Edwards, Andrew N. Sharpley

Biosystems and Agricultural Engineering Faculty Publications

Rainfall simulators have a long history of successful use in both laboratory and field investigations. Many plot–scale simulators, however, have been difficult to operate and transport in the field, especially in remote locations where water or electricity is unavailable. This article describes a new rainfall simulator that is relatively easy to operate and transport to and from the field while maintaining critical intensity, distribution, and energy characteristics of natural rainfall. The simulator frame is constructed from lightweight aluminum pipe with a single 50 WSQ nozzle centered at a height of 3 m (9.8 ft). An operating nozzle pressure of 28 …

Monitoring Subsurface Drainage Flow At Remote Locations, Stephen R. Workman, Stephen F. Higgins, Scott A. Shearer

Biosystems and Agricultural Engineering Faculty Publications

Laboratory evaluations and field results are presented for a slotted weir used to measure discharge from subsurface drains. The head–discharge curve for the vertical slot is a simple power function with an exponent of 1.5. There was excellent agreement (r² > 0.99 and 1:1 slope) between predicted and observed discharge in laboratory testing of 12 test weirs representing five slot widths. The primary advantages of the vertical slot weir are its simplicity, ease of maintenance, and ability to measure small flow rates. Disadvantages include a tendency for the slot to close a small amount over time as a result of …

Determining Matric Stress With The Modified Cam Clay Energy Relationship, Richard A. Rohlf, Larry G. Wells

Biosystems and Agricultural Engineering Faculty Publications

The stress generated by matric suction, or matric stress, was determined at points along the stress path with an analytical and experimental procedure based on the modified Cam clay energy relationship. Matric stress was found to be approximately constant at large strain for constant water content triaxial compression tests. Matric stress was included in both shear and volume relationships in a critical–state soil model that employed the modified Cam clay yield function. Shear was modeled with a constant matric stress. Slope of the normal compression and recompression lines was adjusted for matric stress using a state function that expressed matric …

Comparing Size In Lime, Mark Whitten

Journal of the Department of Agriculture, Western Australia, Series 4

Extensive research into the management of soil acidity in Western Australia is increasing farmer awareness that lime use can reduce soil acidity and improve crop yields. However, as lime use increases, the question of lime performance and particle size is becoming more critical. Chris Gazey from the Department of Agriculture is heading up the soil acidity project, with the team comprising members from the department, CSIRO and the University of Western Australia. Mark Whitten reports on project outcomes relating to lime particle size.

Evaporation Reduction Potential In An Undisturbed Soil Irrigated With Surface Drip And Sand Tube Irrigation, Masoud Meshkat, Richard C. Warner, Stephen R. Workman

Biosystems and Agricultural Engineering Faculty Publications

The efficiency of drip irrigation is highly dependent on evaporation losses occurring from the constantly saturated soil beneath emitters. Advent of subsurface drip irrigation is in part an approach to curb this inefficiency. An irrigation method, Sand Tube Irrigation (STI), is proposed to increase the efficiency of “Normal” surface applied drip Irrigation (NI method) on permanent tree crops without the need for burying the irrigation tubing. The sand tube consists of removing a soil core beneath the emitter and filling the void with coarse sand. A weighing lysimeter was constructed in the laboratory and instrumented to directly measure temporal evaporation …

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

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

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 …

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) …

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 …

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 …

Sensors For Site-Specific Management, Stuart J. Birrell, J. W. Hummel, K. A. Sudduth

Stuart J. Birrell

Site-specific management (SSM, also known as precision farming, precision agriculture, prescription farming, etc.) is a management strategy that seeks to address within-field variability and to optimize inputs such as pesticides and fertilizers on a point-by-point basis within a field. By reducing over-application and under-application of nutrients and pesticides, this strategy has the potential to improve profitability for the producer and also to reduce the threat of groundwater or surface water contamination from agrichemicals. SSM is being adopted by innovative producers across the country. Agricultural equipment manufacturers, farm input suppliers, and a host of other businesses are working along with publicsector …

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 …

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 …

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 …

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), …

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 …

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 …

Nutrient Mapping Implications Of Short-Range Variability, Stuart J. Birrell

Stuart J. Birrell

Successful site specific nutrient application depends on accurate soil nutrient maps, which are generally developed from grid samples. The implication of short range variability for soil nutrient mapping is investigated. Interpretation of soil nutrient maps must consider the level of confidence associated with estimated values.

Analysis Of Spatial Factors Influencing Crop Yield, K. A. Sudduth, S. T. Drummond, Stuart J. Birrell, N. R. Kitchen

Stuart J. Birrell

The spatial relationship between crop yields and soil and site parameters was modeled using several methods. Yield maps estimated by projection pursuit regression and neural network analysis agreed well with measured yields. These methods also allowed generation of response curves for estimated yield as a function of each of the input parameters. These response curves were useful for investigating the relationship between yields and individual soil and site parameters.

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 …

Comparison Of Variable Rate To Single Rate Nitrogen Fertilizer Application: Corn Production And Residual Soil No3-N, N. R. Kitchen, D. F. Hughes, K. A. Sudduth, Stuart J. Birrell

Stuart J. Birrell

The questions most often asked by farmers when discussing variable rate (VR) fertilizer inputs are "How much will it cost?" and "How will it affect my yields?" Many farmers and custom application services share a reluctance to invest in the time and technology required for variable fertilizer application since studies to answer these questions are few and results have been inconsistent.

Compact – A Reclamation Soil Compaction Model Part Ii. Sensitivity Analysis And Applications, Ronald L. Bingner, Larry G. Wells

Biosystems and Agricultural Engineering Faculty Publications

COMPACT, a physically based, event-oriented compaction model, was developed as a management or research tool to evaluate the influence of a surface mining system on compaction of soil material during reclamation. Two systems of area mining reclamation operations were simulated by COMPACT. The first system involved scrapers and bulldozers and the second also included trucks. Scrapers or trucks were used to pick up and deposit the soil material. Bulldozers were then used to shape the site for reclamation. The simulated results were compared with measured results and show how equipment patterns and soil parameters can affect overall soil compaction. This …

Compact – A Reclamation Soil Compaction Model Part I. Model Development, Ronald L. Bingner, Larry G. Wells

Biosystems and Agricultural Engineering Faculty Publications

A physically based, event oriented soil compaction model, known as COMPACT, was developed as a management or research tool to evaluate the effect of surface mining systems on compaction of soil material during reclamation. Simulation of compaction throughout the soil profile at a surface mining reclamation site requires information describing how equipment moves on the site. The compaction processes that are caused by vehicles throughout the soil profile are described by applying the pressure distribution of the surface contact area of a tire or track to determine stresses in the soil profile. A virgin compression curve is then used to …