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Full-Text Articles in Biomedical Engineering and Bioengineering

A Conservation Tillage Educational Program, Elbert C. Dickey, Paul J. Jasa, David P. Shelton Oct 1991

A Conservation Tillage Educational Program, Elbert C. Dickey, Paul J. Jasa, David P. Shelton

Biological Systems Engineering: Papers and Publications

An educational program was conducted to enhance the adoption of conservation tillage practices in targeted areas to reduce soil erosion and on-farm fuel use. Traditional extension methods such as meetings, field days, demonstrations, and plots were used extensively. In addition, the following nontraditional educational methods were used to achieve project objectives: targeting high priority areas, local program guidance committees, surveys to evaluate perceptions and use of conservation tillage, employment of extension assistants to work in the target areas, use of a rainfall simulator to demonstrate the effectiveness of residue cover in reducing erosion, and small group or "coffee shop" meetings …


Area Conservation Tillage Meetings-A Successful Educational Program, Elbert C. Dickey, Paul J. Jasa, David P. Shelton, Robert Grisso, Keith Glewen Oct 1991

Area Conservation Tillage Meetings-A Successful Educational Program, Elbert C. Dickey, Paul J. Jasa, David P. Shelton, Robert Grisso, Keith Glewen

Biological Systems Engineering: Papers and Publications

Interest in conservation tillage began to increase in the early 1980s, and farmers wanted information on how to adopt and manage various tillage and planting systems. Area conservation tillage meetings were developed by the University of Nebraska Cooperative Extension to provide the needed information on a regional basis. Local extension agents and Soil Conservation Service personnel helped extension specialists determine program content. The multidisciplinary meetings included farmer presentations and allowed space and time for commercial exhibits. About 80% of respondents to meeting evaluations indicated they planned to change their tillage practices as a result of the information presented.


Roughness Coefficients For Selected Residue Materials, John E. Gilley, Eugene R. Kottwitz, Gary A. Wieman Aug 1991

Roughness Coefficients For Selected Residue Materials, John E. Gilley, Eugene R. Kottwitz, Gary A. Wieman

Biological Systems Engineering: Papers and Publications

Analysis of surface runoff on upland areas requires identification of roughness coefficients. A laboratory study is conducted to measure Darcy-Weisbach and Manning roughness coefficients for corn, cotton, peanut, pine needles, sorghum, soybeans, sunflower, and wheat residue. Varying rates of flow are introduced into a flume in which selected amounts of residue are securely attached. Roughness coefficients are calculated from measurements of discharge rate and flow velocity. The laboratory data are used to derive regression equations for relating roughness coefficients to Reynolds number and either percent residue cover or residue rate. Separate equations are developed for Reynolds number values from 500 …


Hydraulic Roughness Coefficients As Affected By Random Roughness, John E. Gilley, S. C. Finkner May 1991

Hydraulic Roughness Coefficients As Affected By Random Roughness, John E. Gilley, S. C. Finkner

Biological Systems Engineering: Papers and Publications

Random roughness parameters are used to characterize surface microrelief. In this study, random roughness was determined following six selected tillage operations. Random roughness measurements agreed closely with values reported in the literature.

Surface runoff on upland areas is analyzed using hydraulic roughness coefficients. Darcy-Weisbach and Manning hydraulic roughness coefficients were identified in this investigation on each soil surface where random roughness values were determined. Hydraulic roughness coefficients were obtained from measurements of discharge rat巳and flow velocity.

The experimental data were used to derive regression relationships which related Darcy-Weisbach and Manning hydraulic roughness coefficients to random roughness and Reynolds number. Random …


Subsoiling, Contouring, And Tillage Effects On Erosion And Runoff, Paul J. Jasa, Elbert C. Dickey Jan 1991

Subsoiling, Contouring, And Tillage Effects On Erosion And Runoff, Paul J. Jasa, Elbert C. Dickey

Biological Systems Engineering: Papers and Publications

A study to evaluate the effectiveness of subsoiling on reducing soil erosion and water runoff from continuous com production was conducted. A rotating boom rainfall simulator was used on replicated treatments having either preplant in-row subsoiling or postplant between-row subsoiling used in both tilled and untilled surface conditions. Tilled and untilled treatments without subsoiling were used as checks. These six treatments were used up-and-downhill and on the contour.

Subsoiling reduced the rate of water runoff but did not significantly reduce the soil erosion rate after equilibrium had been reached between water application and runoff rates. Surface condition and farming direction …


Fertilization Of Crops With Feedlot Manure, Elbert C. Dickey, Gerald Bodman Jan 1991

Fertilization Of Crops With Feedlot Manure, Elbert C. Dickey, Gerald Bodman

Biological Systems Engineering: Papers and Publications

The application of animal manure to farmland is an appropriate and environmentally sound management practice for most feedlot operators. Land application returns nutrients from manure to the soil and helps build and maintain soil fertility. In addition to containing nitrogen, phosphorus and potassium, manure contains trace "elements such as calcium, magnesium, iron and zinc. Manure has also been shown to improve soil tilth, increase water-holding capacity, lessen wind and water erosion and improve aeration. Land application of manure should be viewed as a means to utilize crop nutrients present in the manure for crop production rather than utilizing the land …


A Cooperative Educational Program To Reduce Soil Erosion, David P. Shelton, Elbert C. Dickey, Paul J. Jasa, David A. Biere, Susan Smydra Krotz Jan 1991

A Cooperative Educational Program To Reduce Soil Erosion, David P. Shelton, Elbert C. Dickey, Paul J. Jasa, David A. Biere, Susan Smydra Krotz

Biological Systems Engineering: Papers and Publications

Eastern Nebraska, especially the northeastern portion, has a history of severe soil erosion, due in part to a predominance of steep slopes and highly erodible soils (12). While the average annual allowable soil loss ("T" value) for most of these soils is five tons per acre, some fields have annual soil erosion rates that exceed 100 tons per acre. The loss of topsoil is critical, of course, but erosion from cropland also results in the removal of fertilizers and pesticides, which degrades water quality.

Even though farmers are generally aware that soil erosion is a national problem, many …


Enhancing Soil Conservation Practice Adoption With Targeted Educational Programs, Elbert C. Dickey, David P. Shelton, Paul J. Jasa Jan 1991

Enhancing Soil Conservation Practice Adoption With Targeted Educational Programs, Elbert C. Dickey, David P. Shelton, Paul J. Jasa

Biological Systems Engineering: Papers and Publications

Two independent, but closely related, grant funded educational programs were developed and implemented to reduce soil erosion in selected areas of eastern Nebraska. Traditional extension programming methods as well as other more non-traditional approaches were used extensively to enhance soil conservation practice adoption. In one program, encompassing 220 000 ha (540,000 acre) of cropland, annual soil erosion was reduced by 2.3 million t (2.5 million ton) and annual fuel savings of 1.5 million L (390,000 gal) were achieved through a reduction in the number of tillage operations. In the second project, more than 93 000 m (305,000 ft) of terraces …


Residue Management To Control Soil Erosion By Water, Elbert C. Dickey, David P. Shelton, Paul J. Jasa, Michael C. Hirschi Jan 1991

Residue Management To Control Soil Erosion By Water, Elbert C. Dickey, David P. Shelton, Paul J. Jasa, Michael C. Hirschi

Biological Systems Engineering: Papers and Publications

The Erosion Process

Erosion of topsoil begins when water detaches individual soil particles from clod and other soil aggregates. A single raindrop may seem insignificant, yet collectively, raindrops strike the ground with surprising force. During an intense storm, rainfall can loosen and detach up to 100 tons of soil per acre and can be especially erosive when residue mulch or vegetation are not present to absorb their impact.

Two problems often occur during rainstorms. The rate of rainfall can exceed the rate at which water can enter the soil and raindrop impact forces can partially seal the soil surface. In …


Estimating Percent Residue Cover Using The Line-Transect Method, David P. Shelton, Elbert C. Dickey, Roger Kanable, Stewart W. Melvin, Charles A. Burr Jan 1991

Estimating Percent Residue Cover Using The Line-Transect Method, David P. Shelton, Elbert C. Dickey, Roger Kanable, Stewart W. Melvin, Charles A. Burr

Biological Systems Engineering: Papers and Publications

Estimating Percent Residue Cover Using the Line-Transect Method

The line-transect method is one of the easiest method to use in the field to determine the percent residue cover on the surface. Accurate measurement is necessary to determine if enough cover is present to comply with the conservation plan.

The following is a step-by-step procedure for using the line-transect method to measure the percentage of residue cover.

Step 1

Use a 100-foot or 50-foot measuring tape for measuring residue cover. Other measuring length or even knotted ropes can be used if the appropriate multiplication factor is used to calculate the percentage. …


Performance Of Seedigated And Conventionally Planted Crops, W. S. Leander Jr., Derrel L. Martin, James R. Gilley Jan 1991

Performance Of Seedigated And Conventionally Planted Crops, W. S. Leander Jr., Derrel L. Martin, James R. Gilley

Biological Systems Engineering: Papers and Publications

Seedigation is the use of a moving sprinkler irrigation system to broadcast seeds on the soil surface. Seed germination, plant characteristics and yield for grain sorghum, winter wheat and soybeans that were seedigated and conventionally planted are compared. When the seeding rates for seedigation were increased above that for conventional planting, and adequate moisture was available for germination, grain sorghum and wheat seedigated on tilled surfaces produced yields similar to conventionally planted crops. Seedigation of soybeans into fallow conditions, or when used as a relay crop, was unsuccessful. Shallow disking following seedigation did not improve germination or yield of grain …


Mechanical And Barrier Properties Of Edible Corn And Wheat Protein Films, T. P. Aydt, Curtis Weller, R. F. Testin Jan 1991

Mechanical And Barrier Properties Of Edible Corn And Wheat Protein Films, T. P. Aydt, Curtis Weller, R. F. Testin

Biological Systems Engineering: Papers and Publications

Published methods for production of homogeneous edible films from com and wheat proteins were adapted. Barrier and mechanical properties of the edible films were evaluated with procedures commonly used on polymeric films. Mechanical property data included thickness, elongation, tensile strength, tear strength, and burst strength measurements. Barrier property data included water vapor, oxygen, and carbon dioxide gas transmission rate measurements. Homogeneous com and wheat protein films were found to have low tensile strengths, far less than cellophane. Com films were brittle while wheat films were elastic in comparison to cellophane. All three types of film had low permeabilities for dry …


Equipment For Ridge Planting, Elbert C. Dickey, Paul J. Jasa Jan 1991

Equipment For Ridge Planting, Elbert C. Dickey, Paul J. Jasa

Biological Systems Engineering: Papers and Publications

In ridge plant systems, crops are planted into ridges formed during cultivation of the previous crop.

Row cleaning devices on the planter push weed seed and residue lying on the soil surface from the ridge to the area between the rows, or row middles. The crop seed is planted into the old row in a cleanly tilled strip at a higher elevation than the row middles. A band application of herbicide behind the planter typically is used in the row for weed control. Crop cultivation controls weeds between the row and rebuilds ridges for the following year.

Ridge plant systems …