Biomedical Engineering and Bioengineering Commons^™

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

Biological Systems Engineering: Papers and 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

Biological Systems Engineering: Papers and 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

Biological Systems Engineering: Papers and 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 …

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

Biological Systems Engineering: Papers and 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

Biological Systems Engineering: Papers and 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.

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

Biological Systems Engineering: Papers and 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 …

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

Biological Systems Engineering: Papers and 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 …

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

Biological Systems Engineering: Papers and 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

Biological Systems Engineering: Papers and 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 …