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Full-Text Articles in Biological Engineering
Nebraska's Modified-Open-Front Farrowing Houses Design And Operation, Gerald R. Bodman, Donald G. Levis, Duane E. Reese
Nebraska's Modified-Open-Front Farrowing Houses Design And Operation, Gerald R. Bodman, Donald G. Levis, Duane E. Reese
Department of Biological Systems Engineering: Papers and 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
Size Distribution Of Sediment As Affected By Surface Residue And Slope Length, John E. Gilley, S. C. Finkner, G. E. Varvel
Department of Biological Systems Engineering: Papers and 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 …
A Mathematical Model For The Fate Of Hazardous Substances In Soil: Model Description And Experimental Results, W. Greeney, C. Caupp, Ronald C. Sims
A Mathematical Model For The Fate Of Hazardous Substances In Soil: Model Description And Experimental Results, W. Greeney, C. Caupp, Ronald C. Sims
Biological Engineering Faculty Publications
A mathematical model (VIP) was developed and implemented for evaluating the fate of a hazardous substance in the unsaturated zone of the soil. The model simulates vadose zone processes including volatilization, degradation, adsorption/desorption, advection, and dispersion. Four physical phases in the vadose zone are considered including water, oil, soil grains, and soil-pore air (unsaturated pore space). The Vadose Zone Interactive Processes (VIP) model is appropriate for sites under RCRA and CERCLA (Superfund) categorization since site-specific soil-waste processes affecting transport of hazardous chemicals through the vadose zone are incorporated in the model. A RCRA land treatment system was chosen as the …
The Effect Of Temperature On Polycyclic Aromatic Hydrocarbon Persistence In An Unacclimated Agricultural Soil, M. P. Coover, Ronald C. Sims
The Effect Of Temperature On Polycyclic Aromatic Hydrocarbon Persistence In An Unacclimated Agricultural Soil, M. P. Coover, Ronald C. Sims
Biological Engineering Faculty Publications
A laboratory study was conducted to investigate the effect of temperature on the persistence of polycyclic aromatic hydrocarbons (PAHs) incubated in an unacclimated agricultural sandy loam soil. Soil microcosms were spiked with 16 priority pollutant PAHs and placed in incubation chambers at 10, 20, and 30°C. Triplicate sets of microcosms at each temperature were periodically removed from incubation over the 240 day study period and solvent extracted. Concentrations of PAHs in the soil were determined by HPLC analysis of the extracts. Substantial loss of three-ring compounds was observed at all temperatures whereas there was very little apparent loss of five …
Slope Length And Surface Residue Influences On Runoff And Erosion, John E. Gilley, S. C. Finkner, G. E. Varvel
Slope Length And Surface Residue Influences On Runoff And Erosion, John E. Gilley, S. C. Finkner, G. E. Varvel
Department of Biological Systems Engineering: Papers and 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
Slot Injection Of Herbicides, Paul J. Jasa, Elbert C. Dickey, Thomas R. Peterson
Department of Biological Systems Engineering: Papers and 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.
The Rate Of Benzo[A]Pyrene Apparent Loss In A Natural And Manure Amended Clay Loam Soil, M. P. Coover, Ronald C. Sims
The Rate Of Benzo[A]Pyrene Apparent Loss In A Natural And Manure Amended Clay Loam Soil, M. P. Coover, Ronald C. Sims
Biological Engineering Faculty Publications
A study was conducted to evaluate the rate of Benzo[a]pyrene apparent loss from a previously uncontaminated agricultural clay loam soil and to determine the effect of cow manure, as organic substrate amendment, on B[a]P apparent loss. Soil microcosms were spiked with 10 μg/g B[a]P and incubated at 20°C. Triplicate sets of microcosms were periodically removed from incubation and solvent extracted. Concentrations of B[a]P in the soil were determined by HPLC analysis of the extracts. Under the conditions of this study manure was an ineffective amendment for increasing the rate of B[a]P apparent loss in the Durant clay loam soil. In …
Conservation Tillage: Perceived And Actual Use, Elbert C. Dickey, Paul J. Jasa, Bryn J. Dolesh, Lisa A. Brown, S. Kay Rockwell
Conservation Tillage: Perceived And Actual Use, Elbert C. Dickey, Paul J. Jasa, Bryn J. Dolesh, Lisa A. Brown, S. Kay Rockwell
Department of Biological Systems Engineering: Papers and 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 …