Biological Engineering Commons^™

Surface Cover Provided By Selected Legumes, John E. Gilley, J. F. Power, P. J. Reznicek, S. C. Finkner

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The use of legumes in conservation tillage systems may yield several benefits including reduced erosion resulting from establishment of surface cover. The effectiveness in furnishing surface cover of 18 plant species seeded on three different dates was evaluated over an 11-month period. For several of the legume species, planting date significantly influenced maximum surface cover and the number of days required to reach maximum cover. For each of the planting dates, hairy vetch achieved maximum cover as rapidly as any other legume and maintained the greatest cover throughout the study period. Relationships for estimating legume surface cover from vegetative mass …

Germ Weight, Germ Oil Content, And Estimated Oil Yield For Wet-Milled Yellow Dent Corn As Affected By Moisture Content At Harvest And Temperature Of Drying Air, Curtis L. Weller, Marvin R. Paulsen, Stephen Mbuvi

Department of Agricultural and Biological Systems Engineering: Faculty Publications

A split-plot experimental design was used to determine the effect of moisture content at harvest and temperature of drying air on weight, oil content, and estimated oil yield of corn germs recovered from laboratory wet milling. The effects were determined for a high-yielding hybrid of yellow dent corn widely grown in the corn belt that was hand-picked and hand-shelled. Germ oil content decreased significantly as moisture content at harvest and temperature of drying air increased. Germ weight and estimated oil yield generally decreased as both moisture content at harvest and temperature of drying air increased from 17.2 to 29.6% and …

Determining Crop Residue Cover With Electronic Image Analysis, Elbert C. Dickey, David P. Shelton, G.E. Meyer, K.T. Fairbanks

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Crop residue management is one of the best and most efficient soil conservation methods available to farmers. Determinations of the percentage of the soil surface covered with crop residue are often needed for: soil conservation research; erosion control demonstrations; and maintaining compliance with federal, state, or local soil conservation regulations. A number of methods can be used to estimate residue cover, however, many have limitations. To help overcome some of these limitations, a technique, which uses readily-available microcomputer-related hardware and standard video camera equipment has been developed to estimate crop residue cover from photographic slides. This procedure is relatively rapid, …

Enhancing The Adoption Of Soil Conservation Practices With Targeted Educational Programs, David P. Shelton, Elbert C. Dickey, Paul J. Jasa, David A. Biere

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Two independent, but closely related, grant funded educational programs have been developed and implemented to reduce soil erosion in selected areas of eastern Nebraska, U.S.A. Traditional extension programming methods as well as other more nontraditional approaches have been extensively used. In one program, encompassing 220,000 ha of cropland, annual soil erosion has been reduced by 2.5 Mt and annual fuel savings of 1.5 ML have been achieved through a reduction in the number of tillage operations. During a one-year period in the second project, more than 81,000 m of terraces were constructed, which resulted in an annual soil erosion reduction …

Measurement Of Flow Components On Upland Areas Using Dye Dilution Techniques, S. C. Finkner, John E. Gilley

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Dye dilution techniques can be used to measure rill and interrill-to-rill flow rates on upland areas. Procedures and equations for making flow measurements are described along with equations for estimating interrill length and width. If measurements of interrill length and rill width are available, use of simplified flow equations is possible.

Water and dye continuity concepts were utilized to develop generalized interrill-to-rill flow relationships. Measurement of flow from interrill-to-rill areas requires information on the concentration and rate of dye injection, and flow rate and dye concentration on both rill and interrill areas at a downslope sampling location. Dye dilution techniques …

Comparison Of Bulk Density Beneath A Belt Track And Tire, Leonard L. Bashford, A. J. Jones, L. N. Mielke

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Wheel traffic is considered a major cause of soil compaction in production agriculture. Soil compaction depends on initial conditions, load, contact area and tire type and shape at the soil surface. The use of tractors equipped with tracks instead of tires has the potential of reducing soil compaction because of reduced surface contact pressure and difference in load distribution over a relatively long-narrow track. The introduction of a new agricultural tractor equipped with a rubber belt track permits a crawler tractor to compete with a large four-wheel drive tractor in both speed and mobility.
Soil bulk density was measured as …

A Timesaving Method For Labeling Figures, Tables And References, Randy Carlson

Biological Process Development Facility: Staff Publications

No matter how carefully an author outlines a manuscript, the figures, tables, and bibliographic citations are inevitably renumbered one or more times before the final draft. For example, the addition of a new reference to a late draft will sometimes entail the renumbering of all other references throughout the manuscript. A partial solution to this common technical problem in scientific writing is offered here. It is a refinement of an approach known to many scientists.

Electronic Image Analysis Of Crop Residue Cover On Soil, George E. Meyer, Anthony Stepanek, David P. Shelton, Elbert C. Dickey

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Classification procedures for using both black and white and color imaging systems were developed and tested for determination of percent residue cover on the soil surface from video and slide images. A spectral analysis of the image components was used for determining applicable wavelengths and filters. Color imagery provided an acceptable replacement for manual visual procedures. Black-and-white imagery also worked when appropriate blocking filters were used.

Monitoring Natural Air Corn Drying—A Demonstration Project, Richard O. Pierce, Gary L. Zoubek

Department of Agricultural and Biological Systems Engineering: Faculty Publications

A demonstration project is described where natural air corn drying performance was monitored weekly and drying results were printed in a local newspaper. The newspaper articles also gave management recommendations for the upcoming week. Similar demonstration projects can be conducted using the procedures described in this paper.

Correlation Of Starch Recovery With Assorted Quality Factors Of Four Corn Hybrids, Curtis L. Weller, Marvin R. Paulsen, Marvin P. Steinberg

Department of Agricultural and Biological Systems Engineering: Faculty Publications

A laboratory wet-milling process was developed for use in determining starch recovery of yellow dent corn. The effects of harvest moisture and drying air temperature on starch recovery were investigated for four hybrids. A split split-plot experimental design was used to evaluate the effects. Starch recovery was not significantly different among the hybrids; however, it did decreases both harvest moisture and drying air temperature increased. Starch recovery was correlated with quantitative measures of assorted quality factors. Regression analysis found starch recovery to be a function of starch content, test weight, and ethanol-soluble protein.

Calibration Accuracy Of Pesticide Application Equipment, Robert Grisso, E. J. Hewett, Elbert C. Dickey, R. D. Schnieder, E. W. Nelson

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Afield survey of 140 private and commercial pesticide applicators was conducted during the spring of 1986 in 12 counties of central and eastern Nebraska. The results showed that one out of every three cooperators was applying pesticides within ± 5% of their intended application rate. Results indicated that applicators have reduced application errors from that of a similar survey conducted in 1979. However, most errors still can be traced to incorrect calibration. Ninety-four percent of the cooperators used some type of calibration method. Two-thirds used the "Known Area" method. Those using a calibration method more than once a year had …

Surface Cover From Corn Residue On Sandy Soils, R. Todd, Norman L. Klocke, Elbert C. Dickey, Dennis Bauer

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Corn residue left as surface cover after land preparation and planting by various combinations of tillage implements and surface planters, respectively, was measured on four research/ demonstration sites with sandy soils in Nebraska. Surface cover ranged from 51 to 80% for the no-till treatments to 14 to 53% for the twice-disked treatments. The wide range in cover was due to the amount of antecedent residues from the previous crop and the soil type which ranged from sandy loam to tine sands. Other tillage implements included a rolling cultivator, sweep-plow, and mulch-treader.

Nebraska's Modified-Open-Front Farrowing Houses Design And Operation, Gerald R. Bodman, Donald G. Levis, Duane E. Reese

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Two modified-open-front non-mechanically ventilated farrowing houses with creep boxes were operated over a two year period. Annual energy requirements were in the range of 10.6 to 10.9 cents per crate per day. No adverse effects on pig performance were realized. In most instances pig performance exceeded national standards of excellent performance—survival rates in excess of 90% and 21-day pig weights of 5.9 to 6.8 kg (13 to 15 lb). The study verified that another alternative is available to producers who do not want additional mechanical equipment to operate and maintain.

Size Distribution Of Sediment As Affected By Surface Residue And Slope Length, John E. Gilley, S. C. Finkner, G. E. Varvel

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Runoff samples for determination of size distribution of sediment were collected under simulated rainfall conditions at selected downslope distances on plots covered with sorghum and soybean residue at rates ranging from 0.00 to 6.73 t/ha . The effects of surface residue and slope length on size distribution of sediment were evaluated. Substantial movement of sediment in the form of aggregates was found for each of the residue treatments. Significant differences in size distribution of sediment occurred between residue treatments. For a given residue rate, differences in sediment size distribution were found between sorghum and soybean residue. Size distribution of sediment …

Conservation Tillage: Perceived And Actual Use, Elbert C. Dickey, Paul J. Jasa, Bryn J. Dolesh, Lisa A. Brown, S. Kay Rockwell

Department of Agricultural and Biological Systems Engineering: Faculty Publications

A mail survey of farmers in Nebraska showed their perceived use of conservation tillage was about 55%. However, using the 30% residue cover criterion that the Conservation Tillage Information Center uses to define conservation tillage, a field survey of seven counties in 1984 showed that actual use of conservation tillage was less than 5%. Fewer than 20% of the producers surveyed had more than 20% residue cover remaining after tillage and planting. The field survey also showed disk tillage systems were used by almost 70% of the producers. The moldboard plow was used by only 15% of the producers, thus …

Slope Length And Surface Residue Influences On Runoff And Erosion, John E. Gilley, S. C. Finkner, G. E. Varvel

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Runoff rate, runoff velocity , sediment concentration and soil loss rate of rills or overland flow channels were measured at selected downslope distances on plots with varying rates of sorghum and soybean residue, runoff rate, runoff velocity and soil loss rate usually increased with downslope distance. In general, the presence of greater amounts of crop residue reduced sediment concentration and soil loss rate along the entire slope length. Substantial variations in runoff rate, runoff velocity, sediment concentration and soil loss rate were found with downslope distance on some residue treatments.

Slot Injection Of Herbicides, Paul J. Jasa, Elbert C. Dickey, Thomas R. Peterson

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Injection of thiocarbamate herbicides into a slot created by a coulter was evaluated during a 3-year study in southeastern Nebraska. Control of shattercane, the dominant weed, with the slot injector was similar to conventional double disk incorporation. In both tilled and untilled surface conditions, the slot injector placed the herbicide into the soil with minimal disturbance of the soil and residue. Herbicides which are normally broadcast applied were band applied, reducing chemical costs by two-thirds.

Runoff And Erosion As Affected By Sorghum And Soybean Residue, John E. Gilley, S. C. Finkner, G. E. Varvel

Department of Agricultural and Biological Systems Engineering: Faculty Publications

A rainfall simulator was used to measure the effects of varying rates of sorghum and soybean residue on runoff and erosion. In general, increased surface cover caused reduced runoff, sediment concentration and soil loss. Substantial reductions in erosion resulted from the use of small amounts of crop residue. Regression equations were obtained which related surface cover to residue mass. Equations describing relative runoff, sediment concentration and soil loss as a function of surface cover were also developed. Runoff, sediment concentration and soil loss were all found to be highly correlated to surface cover.

Size Distribution Of Sediment As Affected By Corn Residue, John E. Gilley, S. C. Finkner, R. G. Spomer, L. N. Mielke

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Size distribution of sediment was measured under simulated rainfall conditions at selected downslope distances on plots with corn residue rates ranging from 0.00 to 6.73 t/ha. The formation of rills caused increases in the percentage of larger sized sediment material. Greater surface cover usually resulted in an increase in the percentage of smaller sized sediment.

Considerable variation in the size of sediment from both rill and interrill areas was found with downslope distance. On interrill regions, the presence of residue served to reduce sediment size along the entire plot length. Transport of aggregated sediment occurred on each of the residue …

Tillage Systems For Row Crop Production, Elbert C. Dickey, Paul J. Jasa, Alice J. Jones, David P. Shelton

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Selecting the tillage system best suited to a particular farming situation is an important management decision. Formerly, the traditional system was a moldboard plow operation followed by several secondary tillage operations before planting. This system can be appropriate for poorly drained soils having little or no slope and low erosion potential. However, plowing has several disadvantages . The potential for soil erosion is high on sloping lands, and labor and fuel requirements can be substantially higher than with other tillage and planting systems.

Today, conservation tillage systems are used to reduce preplant tillage operations, thus reducing soil erosion and moisture …

Runoff And Erosion As Affected By Corn Residue: Prt Ii: Rill And Interill Components, John E. Gilley, S. C. Finkner, R. G. Spomer, L. N. Mielke

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Hydraulic and soil loss variables were measured under simulated rainfall conditions at selected downslope distances on plots with corn residue rates ranging from 0.0 to 6.7 t/ha. Application of corn residue produced substantial reductions in runoff rate, runoff velocity, sediment concentration and soil loss rate along the entire slope length. On those plots subject to rilling, runoff rate, sediment concentration and soil loss rate usually increased with downslope distance.

Rill and interrill sediment concentration and soil loss rate were also measured at selected slope lengths. lnterrill sediment concentration changed little with downslope distance while greater interrill soil loss rates were …

Sediment And Dye Concentration Effects On Fluorescence, S. C. Finkner, John E. Gilley

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Because of the relatively large sediment concentrations sometimes found on upland regions, adsorption of fluorescent dye onto sediment may be of concern. A laboratory study was conducted to identify the effects of sediment and dye concentration on adsorption. Sediment and dye concentration were both found to significantly affect adsorptive dye loss of rhodamine WT and sulpho rhodamine B.
Regression equations were developed which related dye adsorption to sediment and dye concentration. For a particular soil and dye material, regression equations may be used to correct for adsorptive dye loss. Sulpho rhodamine B is recommended as the dye of choice for …

Runoff And Erosion As Affected By Corn Residue: Part I. Total Losses, John E. Gilley, S. C. Finkner, R. G. Spomer, L. N. Mielke

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The effects of verying rates of corn residue on runoff and erosion from a loess soil in southwestern Iowa were measured using a rainfall simulator. Consistent reductions in runoff, sediment concentration and soil loss resulted from increased residue application. Small amounts of surface cover produced substantial reductions in erosion. A regression equation relating surface cover to residue weight was obtained. Equations describing relative runoff, sediment concentration and soil loss as a function of surface cover were also developed using regression analysis.

Estimating Residue Cover, Elbert C. Dickey, Paul J. Jasa, David P. Shelton

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Crop residue management through conservation tillage is one of the best and most efficient methods farmers have to control soil erosion. Each year about 140 million tons of topsoil are eroded from Nebraska farmlands. Recent research shows that farmers can greatly reduce this loss by maintaining a residue cover of at least 20 to 30 percent after all tillage and planting operations. Leaving this amount of residue can reduce water caused erosion by 50 percent of what it would be from a cleanly tilled field, while leaving more residue will reduce soil losses even further. Conservation tillage and residue management …

Soil Erosion From Tillage And Planting Systems Used In Soybean Residue: Part I - Influences Of Row Spacing, David P. Shelton, Paul J. Jasa, Elbert C. Dickey

Department of Agricultural and Biological Systems Engineering: Faculty Publications

A rainfall simulator was used to compare soil losses from various tillage and planting systems used in residue from soybeans which had been grown in both wide and narrow spaced rows the previous season. Up and- down hill tillage and planting treatments ranging from a double disk system to no-till planting were evaluated using replicated plots on a silt loam soil in the Nora Series having a 10% slope.

Tillage and planting systems used in soybean residue from narrow spaced rows had soil erosion and soil erosion rates that were reduced by approximately 50% compared to the same systems used …

Soil Erosion From Tillage And Planting Systems Used In Soybean Residue: Part Ii - Influences Of Row Direction, Paul J. Jasa, Elbert C. Dickey, David P. Shelton

Department of Agricultural and Biological Systems Engineering: Faculty Publications

A rainfall simulator was used to compare soil losses from tillage and planting systems used in residue from soybeans. The study was conducted on a silty clay loam soil in the Wymore Series with a 5% slope and on a silt loam soil in the Nora Series with a 10% slope. Tillage and planting treatments, ranging from a moldboard plow system to no-till planting, were evaluated both up and- down hill and on the contour using replicated plots.

For the first rainfall event after tillage and planting, the average soil loss for all systems on the contour was 3.0 t/ha …

Hydraulics Of Perforated Irrigation Trail Tube, John E. Gilley, Jan Feyen

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The author presented a methodology for calculating the hydraulics of trail tubes for center-pivot irrigation systems. While he mentioned several possible difficulties with trail tube irrigation, and stated that they have potential benefits in energy saving and improvements in water-use efficiency, additional clarification and analysis are required before the procedures he presented can be used for the rational design of such systems.
First and most importantly, a potential error in the analysis should be mentioned and discussed. The author used the two-term infiltration model of Philip to describe the water intake beneath a center-pivot irrigation system. The assumption of one-dimensional …

Interril Soil Erosion, Part I. Development Of Model Equations, John E. Gilley, D. A. Woolheiser, D, B. Mcwhorter

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Equations describing overland flow depth, rainfall induced soil detachment and sediment transport capacity on interrill areas were identified. The Darcy-Weisbach equation which included a parameter for predicting flow resistance caused by rainfall was used to calculate depth of overland flow. Soil detachment was determined from an equation incorporating raindrop induced, impact pressure estimates. The product of a soil transport factor, bottom shear stress and flow velocity was used to calculate sediment transport capacity. Nondimensional forms of the model equations were evaluated using existing experimental data.

Interril Soil Erosion, Part Ii. Testing And Use Of Model Equations, John E. Gilley, D. A. Woolhiser, D. B. Mcwhorter

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Laboratory measurements were made of interrill erosion as affected by varying overland flow discharge and slope slope steepness. Soil detachment and sediment transport capacity relations were then evaluated using experimentally obtained information.

The model equations were utilized to further characterize interrill soil erosion. The overland flow region over which the model equations are applicable for a disturbed Nunn clay loam soil was determined from laboratory tests and critical shear stress analyses. The influence of slope length on interrill erosion was also examined.

Soil Erosion From Tillage Systems Used In Soybean And Corn Residues, Elbert C. Dickey, David P. Shelton, Paul J. Jasa, Thomas Peterson

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Rainfall simulation techniques were used to compare soil losses from various tillage systems used on plots where corn and soybeans had been grown the previous season. The two year study was conducted on a silty clay loam soil with a 5% slope and on a silt loam soil with a 10% slope. Five tillage treatments, ranging from a moldboard plow system to no-till, were evaluated for each residue at each site. Tillage and planting operations were conducted up-and-down hill on replicated plots. Total soil loss following 63.5 mm of rainfall applied during a 60 min period averaged more than 40% …