Problem Definition: Farmers have a strong influence on the environment and landscape. Farming is an economic activity, for which economic criteria are predominant. However, farmers may be willing to take into consideration the effects of their practice on landscape and environment and change their behavior accordingly when they consider change as feasible and rewarding. The aim of this study is to understand farmer's current behavior concerning landscape and biodiversity. Eventually, this information will be used in an intervention programme designed to influence the major psychological determinants of environment friendly behavior by farmers and with that actually improve the environmental quality of farm lands. Targetgroup: Farmers in the Netherlands are a relatively well organized category. Many of them participate in different groups that aim to increase relevant knowledge. Few farmers have no ties with other farmers/groups of farmers. This has to be taken into account in the design of the study. There are groups that organize on the basis of their ecological concern and their concern with landscape and biodiversity (Agrarische Natuurverenigingen). Given the aims of this project it is likely that these groups will have more favourable prior attitudes toward the information and measures proposed than farmers/groups with other interests, and that degree of success of the intervention depends on ecological concern expressed in participation in one or more of those organizations. Ideally, the instrument is effective among all farmers but we expect more cooperation from farmers that have shown to be sympathetic towards these goals. The study is performed with 120 farmers that are recruited from Agrarische Natuurverenigingen, in Zeeland, a province in the southwest of the Netherlands. Literature: A questionnaire is developed to measure the potentially relevant psychological determinants of environment friendly behavior by farmers. This questionnaire focuses on constructs derived from the Theory of Planned Behavior (Ajzen, 1991) and the Model of Goal Directed Behavior (Perugini & Bagozzi, 2001). These two models have been used extensively in previous research concerning for example energy saving, regulating of body weight and studying efforts (Armitage & Conner, 2001). The research model is adapted to the issue at hand by focusing on the dilemmatic aspects of the behavioral goals, additionally involving notions of self- and collective efficacy, personal norms, and identity-related concepts. Interviews will be conducted before administering the questionnaire to investigate which constructs are particularly relevant in this specific context. The design of the intervention programme proposes to test the effectiveness of an informational intervention technique and the way effectiveness is moderated by social support and public commitment, to have farmers voluntarily change their agricultural practices. This combination is in line with recent insights on intervention effectiveness (Staats, Harland & Wilke, 2004). Research Questions & Hypotheses: With the questionnnaire we expect to gain insight in which major psychological constructs have a significant effect on farmers' intentions to behave in an environmentally friendly way and how these constructs relate to each other. In a review chapter on the Model of Goal Directed Behavior, Perugini (in press) clearly states that the significance of predictors and their relationships differ in each study and are therefore dependent on the context of the behavior. After a period of one year, farmers will again fill out the questionnaire. This way we will be able to assess changes in intentions, self-reported behaviours and influential psychological determinants. We expect farmers who received information combined with social support to show greater improvement in their behavior compared to the other two groups. Method: 120 farmers from Zeeland, a province in the southwest of the Netherlands will fill out the questionnaire. These farmers are being recruited at the moment via their agricultural organizations. To test which constructs have a significant effect on farmers' intentions to behave in an environmentally friendly way and how these constructs relate to each other, regression analyses will be performed. Data collection will take place in March of this year. In the intervention programme, all participating farmers will be assigned to one of three conditions. One group will receive feedback on their performance relative to that of other farmers in their area using a benchmark tool, comparing their achievements with those of relevant others. The second group will also use this tool, but will also meet in so called social support groups to talk about their options and progress concerning the improvement of their land (see Lewin, 1947; Staats, Harland, & Wilke, 2004). The third group will serve as a control. In March 2007, the participating farmers will again fill out the questionnaire. To test whether farmers who received feedback and social support showed greater improvement in their behavior, multilevel analyses will be performed. Thesis: As this is the first year of the project, the writing of the thesis has not yet started. Part of the project also involves the running of laboratory experiments in which causal relationships between the central variables can be tested. One study has been carried out in which the circumstances under which group members are willing to publicly commit themselves in a public goods dilemma were investigated. Results of this experiment indicate the importance of general trust and the level of possible contributions: when there was a lot at stake, low trusters were more willing than high trusters to publicly commit themselves. A follow-up study on this subject is being carried out at the moment.