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| Registros recuperados: 29 | |
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| Bouzaher, Aziz; Shogren, Jason F.; Holtkamp, Derald; Gassman, Philip W.; Archer, David W.; Lakshminarayan, P.G.; Carriquiry, Alicia L.; Reese, Randall; Kakani, Dharmaraju; Furtan, William Hartley; Izaurralde, R. Cesar; Kiniry, James R.. |
| This report describes an integrated agro-ecological modeling system that was developed to assess the potential economic and soil erosion impacts of different agricultural policies for the Canadian prairie provinces of Alberta, Saskatchewan, and Manitoba. The system was constructed by linking erosion metamodels (response functions), based on multiple simulations of the USDA Erosion Productivity Impact Calculator (EPIIC), with a modified version of Agriculture Canada's Canadian Regional Agriculture Model (CRAM) denoted as RS-CRAM (resource sensitive CRAM). A summary of both the environmental and agricultural decision (RS-CRAM) components are presented, including a description of the modifications and enhancements that were made to CRAM. Results of policy... |
| Tipo: Conference Paper or Presentation |
Palavras-chave: Agricultural and Food Policy; Environmental Economics and Policy. |
| Ano: 1996 |
URL: http://purl.umn.edu/18660 |
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| Bouzaher, Aziz; Shogren, Jason F.; Holtkamp, Derald; Gassman, Philip W.; Archer, David W.; Lakshminarayan, P.G.; Carriquiry, Alicia L.; Reese, Randall; Furtan, William Hartley; Izaurralde, R. Cesar; Kiniry, James R.. |
| The interface between RS-CRAM and the environmental component of the integrated modeling system is described for crops, crop sequences, and management systems representative of western Canada. An experimentally designed set of EPIC simulations were performed to generate erosion output that was used to construct wind and water erosion metamodels (response functions). The results of the EPIC simulations indicate that wind and water erosion would be the dominant erosion problem over most of Saskatchewan and Manitoba. For Alberta, water erosion was predicted to be the dominant problem, except for the southern portion of the province. Erosion impacts were sensitive to tillage and cropping patterns. EPIC-predicted yields did not vary much across tillage, a... |
| Tipo: Working or Discussion Paper |
Palavras-chave: Agricultural and Food Policy; Environmental Economics and Policy. |
| Ano: 1995 |
URL: http://purl.umn.edu/18681 |
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| Bouzaher, Aziz; Shogren, Jason F.; Holtkamp, Derald; Gassman, Philip W.; Archer, David W.; Lakshminarayan, P.G.; Carriquiry, Alicia L.; Reese, Randall; Kakani, Dharmaraju; Furtan, William Hartley; Izaurralde, R. Cesar; Kiniry, James R.. |
| Tipo: Working or Discussion Paper |
Palavras-chave: Agricultural and Food Policy; Environmental Economics and Policy. |
| Ano: 1996 |
URL: http://purl.umn.edu/18674 |
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| Feng, Hongli; Jha, Manoj K.; Gassman, Philip W.. |
| A watershed based model, the Soil and Water Assessment Tool (SWAT), along with transfer coefficients is used to assess alternative principles of allocating nutrient load reduction in the Raccoon River watershed in central Iowa. Four principles are examined for their cost-effectiveness and impacts on water quality: absolute equity, equity based on ability, critical area targeting, and geographic proximity. Based on SWAT simulation results, transfer coefficients are calculated for the effects of nitrogen application reduction. We find both critical area targeting and downstream focus (an example of geographic proximity) can be more expensive than equal allocation, a manifestation of absolute equity. Unless abatement costs are quite heterogeneous across the... |
| Tipo: Conference Paper or Presentation |
Palavras-chave: Environmental Economics and Policy. |
| Ano: 2006 |
URL: http://purl.umn.edu/21131 |
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| Kanwar, Ramesh S.; Reungsang, Pipat; Jha, Manoj K.; Gassman, Philip W.; Ahmad, Khalil; Saleh, Ali. |
| A validation study has been performed using the Soil and Water Assessment Tool (SWAT) model with data collected for the Upper Maquoketa River Watershed (UMRW), which drains over 16,000 ha in northeast Iowa. This validation assessment builds on a previous study with nested modeling for the UMRW that required both the Agricultural Policy EXtender (APEX) model and SWAT. In the nested modeling approach, edge-of-field flows and pollutant load estimates were generated for manure application fields with APEX and were then subsequently routed to the watershed outlet in SWAT, along with flows and pollutant loadings estimated for the rest of the watershed routed to the watershed outlet. In the current study, the entire UMRW cropland area was simulated in SWAT, which... |
| Tipo: Working or Discussion Paper |
Palavras-chave: Calibration; Modeling; Nitrate; SWAT; Validation; Water quality; Resource /Energy Economics and Policy. |
| Ano: 2005 |
URL: http://purl.umn.edu/18440 |
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| Feng, Hongli; Kling, Catherine L.; Gassman, Philip W.. |
| Land use changes to sequester carbon also provide "co-benefits," some of which (for example, water quality) have attracted at least as much attention as carbon storage. The non-separability of these co-benefits presents a challenge for policy design. If carbon markets are employed, then social efficiency will depend on how we take into account co-benefits, that is, externalities, in such markets. If carbon sequestration is incorporated into conservation programs, then the weight given to carbon sequestration relative to its co-benefits will partly shape these programs. Using the Conservation Reserve Program (CRP) as an example, we show that CRP has been sequestering carbon, which was not an intended objective of the program. We also demonstrate that more... |
| Tipo: Working or Discussion Paper |
Palavras-chave: Carbon sequestration; Co-benefits; Conservation Reserve Program; Environmental Economics and Policy. |
| Ano: 2004 |
URL: http://purl.umn.edu/18336 |
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| Feng, Hongli; Kurkalova, Lyubov A.; Kling, Catherine L.; Gassman, Philip W.. |
| This study investigates the carbon sequestration potential and co-benefits from policies aimed at retiring agricultural land in the Upper Mississippi River Basin, a large, heavily agricultural area. We extend the empirical measurement of co-benefits from the previous focus on environmental benefits to include economic transfers. These transfers have often been mentioned as a co-benefit, but little empirical work measuring the potential magnitude of these transfers has previously been undertaken. We compare and contrast five targeting schemes, each based on maximizing different physical environmental measures, including carbon sequestration, soil erosion, nitrogen runoff, nitrogen leaching, as well as the area enrolled in the program. In each case, the... |
| Tipo: Working or Discussion Paper |
Palavras-chave: Carbon sequestration; Co-benefits; Co-effects; Economic transfers; Environmental benefits targeting; Upper Mississippi River Basin; Environmental Economics and Policy; Land Economics/Use. |
| Ano: 2005 |
URL: http://purl.umn.edu/18423 |
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| Burkart, Michael R.; Gassman, Philip W.; Moorman, Thomas B.; Singh, Piyush. |
| Data from seven Management Systems Evaluation Areas (MSEA) were used to test the sensitivity of a leaching model, PRZM-2, to a variety of hydrologic settings common in the Midwest. Results of long-term simulations using regional and generalized input parameters produced ranks of leaching potential similar to those based on measurements. Atrazine leaching was simulated because the use of atrazine was prevalent in the MSEA studies and it frequently occurs in the region's groundwater. Short-term simulations used sit-specific soil and chemical coefficients. Generalized simulations used data available from regional soil databases and standardized coefficients. Accurate short-term simulations were precluded by lack of antecedent atrazine concentrations in... |
| Tipo: Working or Discussion Paper |
Palavras-chave: Environmental Economics and Policy. |
| Ano: 1998 |
URL: http://purl.umn.edu/18506 |
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| Chung, S.W.; Gassman, Philip W.; Huggins, David R.; Randall, G.W.. |
| The Erosion Productivity Impact Calculator (EPIC) model was tested using four years of field data collected at a site near Lamberton, Minnesota, under three different crop rotations: continuous corn (Zea mays L.) or CC, soybean (Glycine max L.)-corn (SC), continuous alfalfa (Medicago sativa L.) or CA. The model was evaluated by comparing measured versus predicted subsurface drainage flow (tile flow), nitrate-nitrogen (NO3-N) loss in tile flow, residual NO3-N in the soil profile, crop N uptake, and yield. Initially, EPIC was run using standard Soil Conservation Service (SCS) runoff curve numbers (CN2) suggested for the soil type at the site. Two different SC runs were performed with a nitrogen fixation parameter denoted as parm(7) set at either 1.0 or 0.3,... |
| Tipo: Working or Discussion Paper |
Palavras-chave: Modeling; Water quality; Crop rotation; Tile drainage; Nitrate leaching; Fertilizer; Crop Production/Industries. |
| Ano: 2000 |
URL: http://purl.umn.edu/18479 |
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| Gassman, Philip W.; Williams, Jimmy R.; Benson, Verel W.; Izaurralde, R. Cesar; Hauck, Larry M.; Jones, C. Allan; Atwood, Jay D.; Kiniry, James R.; Flowers, Joan D.. |
| The development of the field-scale Erosion Productivity Impact Calculator (EPIC) model was initiated in 1981 to support assessments of soil erosion impacts on soil productivity for soil, climate, and cropping conditions representative of a broad spectrum of U.S. agricultural production regions. The first major application of EPIC was a national analysis performed in support of the 1985 Resources Conservation Act (RCA) assessment. The model has continuously evolved since that time and has been applied for a wide range of field, regional, and national studies both in the U.S. and in other countries. The range of EPIC applications has also expanded greatly over that time, including studies of (1) surface runoff and leaching estimates of nitrogen and... |
| Tipo: Working or Discussion Paper |
Palavras-chave: APEX; Carbon sequestration; Climate change; EPIC; Modeling; Soil erosion; Water quality; Research Methods/ Statistical Methods. |
| Ano: 2005 |
URL: http://purl.umn.edu/18372 |
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| Registros recuperados: 29 | |
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