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Articles 31 - 41 of 41

Full-Text Articles in Life Sciences

Simulating The Effects Of Spatially Variable Irrigation On Corn Yields, Costs, And Revenue In Iowa, Kendall C. Dejonge, Amy L. Kaleita, Kelly R. Thorp Aug 2007

Simulating The Effects Of Spatially Variable Irrigation On Corn Yields, Costs, And Revenue In Iowa, Kendall C. Dejonge, Amy L. Kaleita, Kelly R. Thorp

Agricultural and Biosystems Engineering Publications

In this study, the CERES-Maize crop model was used in conjunction with Apollo, a shell program, to evaluate potential improved yield in a central Iowa cornfield on a spatially and temporally variable basis. Five years of historical yield and weather data were used to calibrate the model over 100 spatially variable grid cells for non-irrigated conditions in the 20.25 ha field. This calibrated model then used 28 years of historical weather data to simulate three irrigation scenarios: no irrigation, scheduled uniform irrigation, and precision irrigation. Irrigation improved yield by at least 500 kg ha−1 in half of the ...


Combine Harvester Econometric Model With Forward Speed Optimization, Nathan E. Isaac, Graeme R. Quick, Stuart J. Birrell, William M. Edwards, Bruce A. Coers Jan 2006

Combine Harvester Econometric Model With Forward Speed Optimization, Nathan E. Isaac, Graeme R. Quick, Stuart J. Birrell, William M. Edwards, Bruce A. Coers

Agricultural and Biosystems Engineering Publications

A combine harvester econometric simulation model was developed with the goal of matching the combine forward speed to the maximum harvested net income per acre. The model considers the machinery management costs of owning a combine and platform header for harvesting wheat. A statistical Design of Experiment (DOE) was used to evaluate the model using tri-level variables; the medium values constituted the model base case. Of the 27 input variables, the optimum speed was significantly influenced by the crop area, G/MOG ratio, grain unit price, field yield, field efficiency, grain moisture content, probability of a working day in the ...


Comparison Of Different Styles Of Swine Finishing Facilities Within A Uniform Production System, David R. Stender, Jay D. Harmon, Jerry D. Weiss, Darci Cox Jan 2003

Comparison Of Different Styles Of Swine Finishing Facilities Within A Uniform Production System, David R. Stender, Jay D. Harmon, Jerry D. Weiss, Darci Cox

Agricultural and Biosystems Engineering Publications

Swine originating from one farrowing and nursery source were grown in five different finishing facility types. Three of the facilities were considered contemporary styles and two facilities were based on older technologies. The total data set included information collected on 46,408 pigs from 25 groups. The three contemporary facility styles included a fully slatted, hybrid ventilated facility; a fully slatted tunnel ventilated facility; and a partially slatted naturally ventilated facility. These newer facilities were compared to an older, less environmentally controlled facility and an outdoor feeding lot. No significant differences were observed in production performance of the three styles ...


Minimizing The Use Of Antibiotics In Pork Production, Palmer J. Holden, John Carr, Mark S. Honeyman, James B. Kliebenstein, James D. Mckean, Jay D. Harmon, John W. Mabry, Sherry Hoyer Oct 2002

Minimizing The Use Of Antibiotics In Pork Production, Palmer J. Holden, John Carr, Mark S. Honeyman, James B. Kliebenstein, James D. Mckean, Jay D. Harmon, John W. Mabry, Sherry Hoyer

Iowa Pork Industry Center Fact Sheets

Details on minimizing antibiotic use in pork production such as reducing stress. Other issues to consider include biosecurity measures and increased costs of producing antibiotic-free pigs.


Liquid Dairy Waste Transport And Land Application Cost Comparisons Considering Herd Size, Transport Distance, And Nitrogen Versus Phosphorus Application Rates, Robert T. Burns, A. S. Daugherty, T. L. Cross, D. Raj Raman, G. F. Grandle Jul 2001

Liquid Dairy Waste Transport And Land Application Cost Comparisons Considering Herd Size, Transport Distance, And Nitrogen Versus Phosphorus Application Rates, Robert T. Burns, A. S. Daugherty, T. L. Cross, D. Raj Raman, G. F. Grandle

D. Raj Raman

This study provides cost comparisons for the transport and application of dairy waste slurries based on both phosphorus and nitrogen application rates. Estimated cost comparisons are made for several commonly used systems for dairy waste transport and application. Five dairy sizes ranging from 50 to 2,000 cows using 13 transport and application systems were evaluated. For each dairy size, the costs associated with the transport and application system combinations were determined for transport distances of 0.5, 1.5, and 4.5 miles for both nitrogen and phosphorus-based application rates. Total annual system cost, cost per acre, cost per ...


Economic Analysis Of Variable Rate Management For Corn And Soybean Systems, William D. Batchelor, Bruce A. Babcock, Alfred M. Blackmer, Richard M. Cruse, Thomas S. Colvin, Ramesh S. Kanwar, U. Sunday Tim Jan 2000

Economic Analysis Of Variable Rate Management For Corn And Soybean Systems, William D. Batchelor, Bruce A. Babcock, Alfred M. Blackmer, Richard M. Cruse, Thomas S. Colvin, Ramesh S. Kanwar, U. Sunday Tim

Leopold Center Completed Grant Reports

What is the potential payoff for farmers moving from traditional whole-field management or integrated crop management to precision farming? Using computer models, the investigators sought to analyze how inputs can be applied at optimal rates variably across a field in order to match inputs with crop needs. Over the long term, only modest increases were shown in gross returns from these practices. However, gross returns for individual years can be substantial.


A Case Study Of Bioengineering In America: Profits, Risks And Standards Of Value In The Commercialization Of Monsanto Company's Newleaf Potato, Bridget Lyons, Teresa Ralabate, Nadhim Frangul Jan 1999

A Case Study Of Bioengineering In America: Profits, Risks And Standards Of Value In The Commercialization Of Monsanto Company's Newleaf Potato, Bridget Lyons, Teresa Ralabate, Nadhim Frangul

WCBT Faculty Publications

Last year, approximately 45 million acres of American farmland were planted with crops that had been genetically engineered to either produce their own pesticides, or withstand herbicides. The long and short-term effects of this biotechnology on humans and the environment, are being studied, but remain unknown. Leading the way in the field of bioengineered crops is the Missouri-based Monsanto Company. Monsanto believes that current agricultural practices are inconsistent with sustainable development. The NewLeaf potato is one of three products Monsanto has created to feed the growing world population. The genetically engineered crop produces, in every cell of the plant, a ...


Gis-Based Environmental And Economic Analysis Of Integrated Crop-Livestock Production Systems In Southern Iowa, U. Sunday Tim, Robert W. Jolly, Daniel Otto Jan 1995

Gis-Based Environmental And Economic Analysis Of Integrated Crop-Livestock Production Systems In Southern Iowa, U. Sunday Tim, Robert W. Jolly, Daniel Otto

Leopold Center Completed Grant Reports

Crop and livestock production are important economic components for many rural com­ munities. In 1992, Iowa led the nation in corn and hog production, and ranked second, third, seventh, and eighth, respectively in soybean, cattle and calves, poultry, and dairy cow pro­ duction. Livestock and livestock products generated over 64% of the state's total cash farm receipts during 1992—more than $6.5 billion sales at the farm level.


A Spatial Decision Support System For Livestock Production Planning And Environmental Management, Dharmesh K. Jain, U. Sunday Tim, Robert W. Jolly Jan 1995

A Spatial Decision Support System For Livestock Production Planning And Environmental Management, Dharmesh K. Jain, U. Sunday Tim, Robert W. Jolly

Agricultural and Biosystems Engineering Publications

Spatial decision support systems are used to plan production systems and direct the implementation management strategies that are compatible with environmental protection goals. They enable resource managers to select appropriate production technologies that minimize environmental damage, and evaluate alternative management practices. This article describes a spatial decision support system (SDSS) developed to facilitate planning and management of environmentally sound livestock production. The SDSS integrates a geographic information system, spatial and biophysical modeling, and a knowledge-based system into an interactive tool to select suitable watershed land areas for siting livestock production, to select fields for manure application, and to determine the ...


Impact Of Technological Advance On Farm Family Income Inequality, Yoichiro Kawasaki Jan 1970

Impact Of Technological Advance On Farm Family Income Inequality, Yoichiro Kawasaki

Retrospective Theses and Dissertations

No abstract provided.


Economics Of The Production Of Ethanol, L. A. (Lewis Albert) Kremer Jan 1949

Economics Of The Production Of Ethanol, L. A. (Lewis Albert) Kremer

Retrospective Theses and Dissertations

The cost of producing alcohol naturally varies with the raw material and with the process. In the case of corn alcohol, the raw material charge is the major cost item; therefore, instead of selecting one cost for alcohol from corn, a graph is presented showing estimated cost of producing alcohol vs. the price of corn. The graph is a straight line showing an alcohol cost of 27 to 30 cents per gallon with corn at 40 cents per bushel and an alcohol cost of 83 to 86 cents with corn at $2.00 per bushel. Molasses alcohol is made from ...