Modeling farmers' decision to use conservation tillage and genetically modified soybean seed in a joint framework

Agricultural production has been marked in the past few years by the introduction of genetically modified crop varieties. Adoption of these new varieties and their use for human nutrition remains very controversial. There is little consensus on their potential environmental effects or profitability. There are also persistent questions about the relationship between some of these varieties and other technologies such as conservation tillage. In the US, Roundup ReadyRTM soybean (also known as Glyphosate-resistant soybean) is the most widely used genetically modified crop, accounting for about 80% of U.S. soybean acreage in 2004. There is a need to understand why so many farmers have adopted this technology and what the potential implications of this trend are.;This study aims to make a contribution to the understanding of factors that affect the adoption of Roundup ReadyRTM soybean and No-till, while exploring the potential interrelationship between the two technologies and shedding light on their implications on farm labor as well as herbicides usage.;The theoretical model of joint technology adoption draws from the expected utility maximization framework. This model is used to develop hypothesis linking technology adoption to risk and other factors such farm labor. It also reveals why farmers could adopt a time-saving or risk-reducing technology that does not necessarily improve their agricultural profit.;Based on the structure of the theoretical model, econometric models are developed to empirically estimate factors that affect adoption of the two technologies and to derive the implications of these decisions on input usage. Results of these models did not support the hypothesis that the two technologies were affected by the same unobserved variables. They revealed that farmers with a graduate education were less likely to adopt Roundup ReadyRTM soybean compared to other farmers. Adoption of this technology also leads farmers to use herbicides mixtures that are less damaging to the environment. On the other hand, No-till adoption was not found to lead to the use of more environmentally damaging herbicides. Meanwhile, there was no conclusive evidence that any of the two technologies was labor-saving as hypothesized. There was also little evidence that the adoption of GR soybean affected the use of No-till.