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Economics

Retrospective Theses and Dissertations

Plant Sciences

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Full-Text Articles in Life Sciences

A Stochastic Model Of Maize Gene Dispersal, David G. Ripplinger Jan 2003

A Stochastic Model Of Maize Gene Dispersal, David G. Ripplinger

Retrospective Theses and Dissertations

The spatial distribution of maize genes is predicted using a two dimensional Lagrangian stochastic (LS) model that meets sub-inertial and well-mixed conditions. Using wind data from central Iowa, a Weibull distribution is fit. From this distribution, a series of Monte Carlo simulations are run using the LS model in three forms. The final two forms of the model are based on USDA regulations for the production of pharmaceutical producing corn, demonstrating the model's suitability for analyzing the risk of transgene dispersal in maize. Special considerations are given to the large size of maize pollen, the likelihood of pollen seepage ...


Economic Analysis Of Pesticide Regulation In The U.S. Apple Industry , Jutta Roosen Jan 1999

Economic Analysis Of Pesticide Regulation In The U.S. Apple Industry , Jutta Roosen

Retrospective Theses and Dissertations

Several particularities of apple production systems require careful consideration of the methods used to estimate impacts of pesticide regulation. Growing conditions are geographically diverse, quality considerations are of particular importance, and dynamic aspects need to be acknowledged in production systems of perennial crops;A partial-equilibrium model of the apple industry is estimated where orchards are modeled as multiproduct firms producing apples for fresh and processed consumption. Groups of growers are distinguished by region and by pesticide use patterns. The changes of quantities and prices in the markets for fresh and processed apples that follow a technology shift are derived. Economic ...


Economic Feasibility Of Growing Herbaceous Biomass Energy Crops In Iowa , Young-Woo Park Jan 1996

Economic Feasibility Of Growing Herbaceous Biomass Energy Crops In Iowa , Young-Woo Park

Retrospective Theses and Dissertations

Depletion of natural energy resources and environmental degradation caused by current energy resources (fossil fuels) have rekindled interest in energy availability and developing environmentally benign and renewable alternative energy resources. In addition, the reduced productive capacity of soil and environmental problems in rural areas caused by the loss of topsoil has created interest in ways to conserve soil;These concerns have generated considerable attention on the production of herbaceous energy crops on marginal land as a possible solution to meeting future energy demands, addressing environmental concerns, and reducing soil erosion;This research suggests that herbaceous energy crops, especially switchgrass, can ...


Tradeoffs In Balancing Multiple Objectives Of An Integrated Agricultural Economic And Environmental System , P. G. Lakshminarayan Jan 1993

Tradeoffs In Balancing Multiple Objectives Of An Integrated Agricultural Economic And Environmental System , P. G. Lakshminarayan

Retrospective Theses and Dissertations

This research, which integrates the economic and environmental processes in a multiobjective framework to find comprehensive solution, is a departure from the traditional approach. The problem is motivated by multiattribute utility and social welfare theory, and the conditions for optimality are derived. Since agricultural nonpoint source pollution (NPS) pollution is a nonmarket externality, a motivation based on public policy and social costs is provided to include environmental quality decisions. A conceptual framework for integrating the multidisciplinary models is presented. The environmental data needs of the integrated system was obtained from spatially simulated predictions of the biogeophysical process model, a mathematical ...


Interregional Analysis Of Integrated Crop, Livestock, And Forest Production: A Goal Programming Model , Jianbang Gan Jan 1990

Interregional Analysis Of Integrated Crop, Livestock, And Forest Production: A Goal Programming Model , Jianbang Gan

Retrospective Theses and Dissertations

To satisfy our demand for food and fiber and at the same time to protect the environment on which our lives depend are the two critical issues facing us today. In this study, a sequential linear goal programming model is developed and used to examine the optimal land allocation among agricultural and forest production activities, the land use shifts between agriculture and forestry sectors, and the best management strategies for the nation's forest and range ecosystems under the alternative policies;This national level model consists of six sectors: crop, livestock, forest and range, resource availability, demand, and environment. Four ...


Economics Of Conservation Tillage And Soil Productivity In North Central Iowa: A Control Theory Approach , Carlos Alberto Ibañez-Meier Jan 1985

Economics Of Conservation Tillage And Soil Productivity In North Central Iowa: A Control Theory Approach , Carlos Alberto Ibañez-Meier

Retrospective Theses and Dissertations

The major difficulty in the soil productivity issue is quantifying the user cost of soil erosion. Previous research has failed to answer the question of what soil is worth for crop production. The price of a unit of soil is a costate variable computed in this study by a deterministic optimal control model and found to range from 30.00 to 65.00 per cm. per acre in North Central Iowa, depending upon the tillage method and whether the farmland is managed by society, an owner, or a renter.;Another difficulty is the availability of data showing the long-term effects ...


Fertilizer Production Functions Up To Fourth Order From Experimental Data Applied In Profit Maximization, Supply-Demand Relationships And Marginal Rates Of Substitution For Land, Sati Prasad Bose Jan 1970

Fertilizer Production Functions Up To Fourth Order From Experimental Data Applied In Profit Maximization, Supply-Demand Relationships And Marginal Rates Of Substitution For Land, Sati Prasad Bose

Retrospective Theses and Dissertations

No abstract provided.


Use Of Soil Surveys In Land Valuation For Tax Assessment, Joseph Allen Phillips Jan 1968

Use Of Soil Surveys In Land Valuation For Tax Assessment, Joseph Allen Phillips

Retrospective Theses and Dissertations

No abstract provided.


Some Economic Aspects Of Storing Dura In The Sudan, Ahmed Salim Ahmed Jan 1966

Some Economic Aspects Of Storing Dura In The Sudan, Ahmed Salim Ahmed

Retrospective Theses and Dissertations

No abstract provided.


Economic Implications Of Continuous Row-Cropping In Iowa, Robert Francis Groene Jan 1962

Economic Implications Of Continuous Row-Cropping In Iowa, Robert Francis Groene

Retrospective Theses and Dissertations

No abstract provided.