Marra, Michele C.

December, 2008

By: Walton, Jonathan C.; Lambert, Dayton M.; Roberts, Roland K.; Larson, James A.; English, Burton C.; Larkin, Sherry L.; Martin, Steven W.; Marra, Michele C.; Paxton, Kenneth W.; Reeves, Jeanne M.
Adoption of precision agriculture technology has arrived considerable attention, but abandonment has received little. This paper identified factors motivating adoption and abandonment of precision soils sampling in cotton. Younger producers who farmed more cotton area, owned more of their cropland, planted more non-cotton area, or used a computer 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, or used variable-rate fertilizer application were less likely to abandon precision soil sampling.

December, 2007

By: Sydorovych, Olha; Marra, Michele C.
A revealed-preference-based method is proposed for assessment of the environmental and human health impact of genetically engineered (GE) crops. This method employs the relative pesticide toxicity information from farmers' pesticide choices combined with volume of pesticides as an alternative to previous methods which are based on volume only, on number of pesticide applications, or on stated preferences. The method is applied to estimate the changes in the impact of herbicides after environmental and health perspective. The results indicate that, on average, a reduction in herbicide human heath and environmental impacts occurs when farmers adopt RR soybean varieties.

December, 2003

By: Norwood, F. Bailey; Marra, Michele C.
Pesticide productivity is both important and difficult to measure. Typically, pesticide marginal products are estimated without information on the pest pressure. Three theoretical models are developed which suggest absence of such information may cause an underestimation of pesticide productivity. Using application frequency variables as a proxy for pest populations, we show that pesticide marginal products are higher when pest pressure is accounted for.

July, 2001

By: 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.

July, 1994

By: 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.