OPTIMAL RATE OF APPLIED NITROGEN AND CHOICE OF REDUCED TILLAGE

The objective was to compare optimal long-term farm level investments in conservation tillage systems and annual nitrogen use in wheat production from a private and social perspective. The performance of four tillage systems was simulated on a 243 hectare (600-acre) Oklahoma wheat farm with six soil types. A decomposition method was used to find the optimal tillage system. It was found that private producers would select a disk chisel system while the less erosive sweep system was optimal from a social perspective.Crop Production/Industries,

DYNAMIC SPREADSHEET PROGRAMMING TO SELECT THE MOST COST EFFICIENT MANURE HANDLING SYSTEM

Livestock Production/Industries,

National Crop Model of Thailand

The development of the national model of crop production in Thailand is the result of a joint effort by staff members of the Division of Agricultural Economics and by the Iowa State University team. This national model could not have been developed without the prior efforts of many individuals. Those efforts include previous assistance provided by the United States Agency for International Development in Thailand before the current project began. The leadership of Dr. Somnuk Sriplung. Director of the Division of Agricultural Economics in Thailand, has been a crucial element in the sector analysis project. The staff members of the DAE had developed and administered a general farm survey before the current sector analysis project began. Dr. Earl O. Heady devoted considerable preproject time to developing the project and program work and continued to contribute advice and guidance throughout the project. Iowa State University team members Keith Rogers and LeRoy Blakeslee and numerous DAE staff members worked as a single team to define,analyze and initiate the work program for the construction of the programming models in each of the 19 agroeconomic zones. Transportation and processing costs were estimated by the DAE group assisted by Dennis Conley. The principal policy issues analyzed in this study were developed under the responsibility of the policy advisor, Charles Framingham. The assistance and cooperation of Dr. Framingham were essential in carrying out this study. Encouragement and administrative support were provided by Dr. Fletcher Riggs and Mr. David Lundborg of the United States Agency for International Development in Thailand.https://lib.dr.iastate.edu/dae-card_sectoranalysis/1014/thumbnail.jp

Economic Effects of Environmental Taxation on Chemical Fertilizers

This paper analyzes the economic effects of environmental taxes on chemical fertilizer in producing rice. A charge of 10 percent tax on nitrogen fertilizer leads to a reduction in fertilizer use of 1.5 percent without changing rice yield, but the farm income is reduced by 0.6 percent. The tax rate of 100 percent leads to a reduction of 14.6 percent in fertilizer use, a 0.4 percent reduction in rice yield, and a 3.6 percent reduction in farm income. A significant feature of eco-taxes imposed on chemical fertilizers is their revenue potential, which could contribute to increasing government budgets for finance pollution control programs, such as education and R&D. This study provides an insight into the application of market-based instrument to achieve sustainable agricultural development.polluter-pays-principle, nonpoint pollution, environmental tax, nitrogen fertilizer, negative externalities, Environmental Economics and Policy, Q28, Q52,

System Level Economic Analysis of Swine Diet Modifications

Experimental data from low nitrogen and phosphorus diets (Carter et al, 1999, 2000, 2003) are being used to validate and/or modify the NRC swine growth model. A profit maximizing daily growth model that considers feed costs, excretion, waste management costs, and length of feeding period is being developed.Livestock Production/Industries,

POTENTIAL ECONOMIC IMPACTS OF THE REVISED ENVIRONMENTAL PROTECTION AGENCY "CAFO RULE"

Environmental Economics and Policy,

OPTIMAL SPATIAL ALLOCATION OF WASTE MANAGEMENT PRACTICES TO REDUCE PHOSPHORUS POLLUTION IN A WATERSHED

Phosphorus pollution from excessive litter application and municipal discharges causes eutorphication of lakes in the Eucha-Spavinaw watershed in eastern Oklahoma and western Arkansas. Consequent algae blooms impair the taste of drinking water supply drawn from the watershed and reduce the recreational values of the lakes. The paper shows how GIS data based biophysical modeling can be used to derive spatially optimal, least-cost allocation of agricultural management practices to be combined with optimal wastewater treatment activity from the point source in order to achieve socially optimal phosphorus load in the watershed. The optimal level of phosphorus load is determined by equating marginal abatement with marginal damage cost. Transportation activities in the model allow for transportation of litter within and out of the watershed. Results show uniform regulation of litter application is excessively costly relative to measures that encourage adoption of management practices that equate marginal abatement costs across pollution sources. The results also show that change in the land use patterns in a long-run and using alum based litter additives in short-run are economically efficient management options.Environmental Economics and Policy,

Decision Support System for Evaluating Rural Water Supply Infrastructure Scenarios

This paper seeks to develop a methodology that will be useful for rural water districts in assessing the future of their water systems infrastructure. In particular, the use of free water simulation software and publicly available data on population, roads, and terrain present rural water systems with the opportunity to analyze their existing distribution system and forecast where problems are likely to occur. This methodology will allow various alternatives (such as consolidation with a neighboring system, or pipe upgrades) to be evaluated and the costs of implementing these alternatives to be explored. Finally, different avenues for funding the associated costs can be summarized and presented to the community, including the steps needed to apply for popular grant and loan programsRural Water, Infrastructure, Simulation, EPANET, Community/Rural/Urban Development, R53, R58,

Effect of Corn Price on Profitability of Control Vs Phytase Enhanced Diet of Hogs

Economic Simulation model (SIMETAR) was used to investigate the effect of future corn price on profitability of control and phytase enhanced diet of hogs. The completed simulation model was used to estimate probability distribution for control vs lower excretion diet profitability under different corn prices. Data used was collected from recent field trials in Oklahoma that tested the effect of phytase enhanced diets on reducing phosphorus emission. The results showed that as the market price of corn increases control diet will be more profitable than phytase enhanced diet, given the cost of other remaining feed ingredient is constant for both the diets.profitability, SIMETAR, control diet, phytase enhanced diet, swine, Production Economics,

Integrated Reservoir Management under Stochastic Conditions

Economic optimization, Lake levels, Marketed and non-marketed water uses, Non-linear programming, Recreational benefits, Reservoir management, Stochastic inflows, Value of a visitor day, Environmental Economics and Policy, International Development, Land Economics/Use, Production Economics, Productivity Analysis, Public Economics, Resource /Energy Economics and Policy, Risk and Uncertainty,