Biomedical Engineering and Bioengineering Commons^™

Irrigation Soybeans By Growth Stages In Nebraska, N. L. Klocke, Dean E. Eisenhauer, James E. Specht, Roger Wesley Elmore, Gary W. Hergert

Biological Systems Engineering: Papers and Publications

Irrigated soybean production in Nebraska spans a region with diverse soils and climates. Irrigators can easily adopt irrigation scheduling using a stage of growth for timing applications. However, simplifying assumptions, including soil water holding capacity, rainfall, stored soil water, and adequate irrigation system capacity, are implicit in the development of stage of growth irrigation scheduling recommendations. Reliance on these can lead to misapplication of irrigation water.
This project tested irrigation scheduling techniques for indeterminate soybean production in Nebraska, with stage of growth indicating the initiation of irrigation. The range of soils and climate in the study area gave a range …

A Simplified Equation For Modeling Sediment Transport Capacity, S. C. Finkner, M. A. Nearing, G. R. Foster, John E. Gilley

Biological Systems Engineering: Papers and Publications

Sediment transport capacity for shallow overland flow was represented as a quadratic function of downslope distance using the assumption of a linear increase in overland flow discharge with downslope distance and an approximation to the Yalin equation for sediment transport capacity. The simplified equation for sediment transport applies to complex topography having uniform soil and management characteristics. The simplified equation accurately approximated the Yalin equation when calibrated using the average of the hydraulic shear stresses at the end of a constant slope reference profile and the end of the actual profile. The simplified equation is useful in deriving closed-form solutions …

Performance Of Solar-Assisted Modified-Open-Front Swine Nurseries, G. R. Bodman, M. F. Kocher, J. A. Deshazer

Biological Systems Engineering: Papers and Publications

Performance data of two modified-open-front non-mechanically ventilated swine nurseries have shown that solar energy can be effectively utilized to maintain a productive environment within the animal space during cold weather (temperatures as low as -26°C ( - 15 °F). The nurseries feature a monoslope roof design and passive collector panels that also function as warm weather ventilation panels. An active solar-heating system uses a ground-level collector operated in conjunction with an in-floor solar heat distribution and storage system. The nurseries were designed to handle pigs weighing from 7 to 23 kg (15 to 50 lb). An average of 19% of …

Management Strategies To Minimize And Reduce Soil Compaction, A. J. Jones, R. A. Wiese, Elbert C. Dickey

Biological Systems Engineering: Papers and Publications

Nature has some built-in processes that reduce soil compaction. They include cycles of wetting and drying, and freezing and thawing.

In the last 20 to 30 years, farming practices have changed drastically. These farming changes have made it more difficult for nature to rejuvenate the soil environment to an optimum condition for crops. Performing field operations on wet soils, using multiple field operations to grow the same crop continuously, and eliminating meadow crops from crop rotations contribute to more extensive and deeper compaction.

Each farmer has the opportunity to make decisions that can keep soils from becoming compacted.

Adoption of …

Evaluation Of Irrigation Planning Decisions, Derrel L. Martin, James R. Gilley, Raymond J. Supalla

Biological Systems Engineering: Papers and Publications

A method is developed to determine optimal irrigation strategies for a single season using crop production functions which incorporate physically based coefficients. The relationship of yield to evapotranspiration is used to develop the yield-irrigation function. The physical parameters used in the production function can be determined from field measurements or various types of computer simulation. Using this approach, the optimal irrigated area and depth of water to apply can be related to prices, costs, and physical parameters. This produces a more general solution than commonly used production functions that depend on limited experimental results. The optimal irrigation depth and irrigated …

Performance And Design Of Vegetative Filters For Feedlot Runoff Treatment, Elbert C. Dickey, D. H. Vanderholm

Biological Systems Engineering: Papers and Publications

Installation of a zero-discharge, runoff-control system is one method for solving potential water pollution problems from many feedlot operations. Even though the zero-discharge system is required by regulation in several states, this approach may be economically prohibitive for many small operations. An alternative is to install a vegetative filter system to adequately control the runoff so that violations of water quality standards will not occur during storm runoff. Vegetative filters are systems in which a vegetative area such as pasture, grassed waterways, or even cropland is used for treating feedlot runoff by settling, filtration, dilution, adsorption of pollutants and infiltration. …

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

Biological Systems Engineering: Papers and 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 …

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

Biological Systems Engineering: Papers and 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 …

The Cost Of Misapplication Of Herbicides, Robert Grisso, Elbert C. Dickey, Larry D. Schulze

Biological Systems Engineering: Papers and Publications

A field survey of 103 private herbicide applicators was conducted during the spring of 1986 in 12 central and eastern Nebraska counties. The results showed that only 30% of the cooperators were applying herbicides within 5% of their intended application rate. Twenty-six percent of the cooperators over-applied herbicides during a single application, with an average cost due to misapplication of $3.11/ha ($1.26/a). If these values were extended over Nebraska, $4.26 million are expended for extra herbicides which were not necessary. The average cost of over application was in excess of $570 per application. Forty-four percent of the cooperators under-applied herbicides …

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

Biological Systems Engineering: Papers and 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 …

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

Biological Systems Engineering: Papers and 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, …