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| Registros recuperados: 43 | |
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| Alston, Julian M.; Marra, Michele C.; Pardey, Philip G.; Wyatt, T.J.. |
| A total of 289 studies of returns to agricultural R&D were compiled and these provide 1821 estimates of rates of return. After removing statistical outliers and incomplete observations, across the remaining 1128 observations the estimated annual rates of return averaged 65 per cent overall — 80 per cent for research only, 80 per cent for extension only, and 47 per cent for research and extension combined. These averages reveal little meaningful information from a large body of literature, which provides rate‐of‐return estimates that are often not directly comparable. This study was aimed at trying to account for the differences. Several features of the methods used by research evaluators matter, in particular assumptions about lag lengths and the... |
| Tipo: Journal Article |
Palavras-chave: Research and Development/Tech Change/Emerging Technologies. |
| Ano: 2000 |
URL: http://purl.umn.edu/117834 |
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| Vukina, Tomislav; Levy, Armando; Marra, Michele C.. |
| The paper uses data from the Conservation Reserve Program (CRP) auctions to elicit farmers' attitudes toward the environment by analyzing their bids. The CRP pays farmers to remove land from production and put it to a conservation use. An interesting aspect of these auctions is that winners are determined by a combination of low bids and environmental scores of individual plots. The results indicate that farmers condition their bids on the strength of their environmental scores and that they consistently value those environmental improvements which are concentrated locally such as reduced soil erosion, while they place less emphasis on those benefits which resemble public goods such as air quality and wildlife habitat. |
| Tipo: Conference Paper or Presentation |
Palavras-chave: Environmental Economics and Policy; D44; D82; Q51; Q58. |
| Ano: 2006 |
URL: http://purl.umn.edu/25233 |
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| Marra, Michele C.; Gould, Thomas D.; Porter, Gregory A.. |
| A model is developed to determine the minimum weed population where a decision to apply a postmergence herbicide would be profitable. The economic threshold model accounts for changing economic conditions, the effect of weeds on crop quality, the effect of multiple weed species on yield and quality, and uncertainty about spraying period length. The model is uncomplicated enough for microcomputer or programmable calculator applications. An example of weed threshold calculations for round white potatoes is given. |
| Tipo: Journal Article |
Palavras-chave: Crop Production/Industries. |
| Ano: 1989 |
URL: http://purl.umn.edu/28804 |
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| Alston, Julian M.; Marra, Michele C.; Pardey, Philip G.; Wyatt, T.J.. |
| A total of 294 studies of returns to agricultural R&D (including extension) were compiled and these studies provide 1,858 separate estimates of rates of return. This includes some extreme values, which are implausible. Then the highest and lowest 2.5 percent of the rates of return were set aside, the estimated annual rates of return averaged 73 percent overall—88 percent for research only, 45 percent for research and extension, and 79 percent for extension only. But these averages reveal little meaningful information from a large and diverse body of literature, which provides rate-of –return estimates that are often not directly comparable. The purpose of this study was to go behind the average, and try to account for the sources of differences, in a... |
| Tipo: Working or Discussion Paper |
Palavras-chave: Research and Development/Tech Change/Emerging Technologies. |
| Ano: 1998 |
URL: http://purl.umn.edu/16056 |
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| Martin, Steven W.; Roberts, Roland K.; English, Burton C.; Larson, James A.; Cochran, Rebecca L.; Goodman, W. Robert; Larkin, Sherry L.; Marra, Michele C.; Shurley, W. Donald; Reeves, Jeanne M.. |
| Probit analysis identified factors influencing adoption of precision farming technologies by Southeastern cotton farmers. Younger, more educated farmers who operated larger farms and were optimistic about the future of precision farming were most likely to adopt site-specific information technology. The probability of adopting variable rate input application technology was higher for younger farmers who operated larger farms, owned more of the land they farmed, were more informed about the costs and benefits of precision farming, and were optimistic about the future of precision farming. Computer use was not important possibly because custom hiring shifts the burden of computer use to agribusiness firms. |
| Tipo: Conference Paper or Presentation |
Palavras-chave: Research and Development/Tech Change/Emerging Technologies. |
| Ano: 2004 |
URL: http://purl.umn.edu/34768 |
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| Marra, Michele C.; Hubbell, Bryan J.; Carlson, Gerald A.. |
| In 1996, Bt cotton became one of the first genetically engineered crops to be available commercially. This study focuses on the various sources and quality of information about Bt cotton profitability available to farmers in the Southeast and assesses the relative importance of such information in the farmers' adoption decisions. A model of the individual decision to adopt is developed to incorporate two recent theories of the role of information quality (the "effective information" hypothesis and the "popularity" hypothesis) as well as the effect of current technology depreciation. The data show some support for all three factors as determinants of adoption. |
| Tipo: Journal Article |
Palavras-chave: Crop Production/Industries. |
| Ano: 2001 |
URL: http://purl.umn.edu/31158 |
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| Marra, Michele C.; Schurle, Bryan W.. |
| A meta-analysis approach to prediction of farm level yield risk from county level yield series is applied to Kansas wheat yields. A nonlinear relationship between county level and farm level yield risk is found, which indicates that yield risk increases at an increasing rate as the number of acres in the risk measure decreases. County level yield variability should be adjusted upward by approximately .1% for each percent difference in county acreage and average farm acreage within the county. The meta-analysis approach is shown to be promising for the prediction of farm level yield risk when farm level information is difficult to obtain. |
| Tipo: Journal Article |
Palavras-chave: Risk and Uncertainty. |
| Ano: 1994 |
URL: http://purl.umn.edu/31228 |
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| Walton, Jonathan C.; Roberts, Roland K.; Lambert, Dayton M.; Larson, James A.; English, Burton C.; Larkin, Sherry L.; Martin, Steven W.; Marra, Michele C.; Paxton, Kenneth W.; Reeves, Jeanne M.. |
| Technology adoption in precision agriculture has received considerable attention, while abandonment has received little. Our objective was to identify factors motivating adoption and abandonment of precision soil sampling in cotton. Results indicate younger producers who farmed more cotton area, owned more of their cropland, planted more non-cotton area, used a computer, or used a Personal Digital Assistant (PDA) were more likely to adopt precision soil sampling. Those with more cotton area or who owned livestock were more likely to abandon, while those who used precision soil sampling longer, used a PDA, or used variable-rate fertilizer application were less likely to abandon. |
| Tipo: Conference Paper or Presentation |
Palavras-chave: Crop Production/Industries. |
| Ano: 2008 |
URL: http://purl.umn.edu/6215 |
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| Roberts, Roland K.; English, Burton C.; Larson, James A.; Cochran, Rebecca L.; Goodman, W. Robert; Larkin, Sherry L.; Marra, Michele C.; Martin, Steven W.; Reeves, Jeanne M.; Shurley, W. Donald. |
| Precision Farming by Cotton Producers in Six Southern States: Results from the 2001 Southern Precision Farming Survey |
| Tipo: Report |
Palavras-chave: Cotton; Precision farming; Survey; Agribusiness; Farm Management; Production Economics; Research and Development/Tech Change/Emerging Technologies. |
| Ano: 2002 |
URL: http://purl.umn.edu/91331 |
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| Walton, Jonathan C.; Larson, James A.; Roberts, Roland K.; Lambert, Dayton M.; English, Burton C.; Larkin, Sherry L.; Marra, Michele C.. |
| This research analyzed the adoption of Personal Digital Assistants (PDA) and handheld Global Positioning System (GPS) devices in cotton production. Analysis using a logit model found that younger farmers who used a crop consultant, remote-sensing, variable-rate fertilizer, and reported greater yield variability had a higher probability of adopting. |
| Tipo: Conference Paper or Presentation |
Palavras-chave: Farm Management; Research and Development/Tech Change/Emerging Technologies. |
| Ano: 2008 |
URL: http://purl.umn.edu/6839 |
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| Registros recuperados: 43 | |
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