California has implemented one of the most aggressive agricultural nitrogen management policies in the United State, called the Irrigated Lands Regulatory Program (IRLP). The IRLP requires farmers to join “Coalition Groups”, which entails attending nitrogen management education programs and disclosing information about practices and nitrogen application.

This talk will summarize research led by Mark Lubell, Professor and Director of the Center for Environmental Policy and Behavior at the University of California, Davis, focused on farmer decision-making based on surveys from growers in California’s Central Valley. The research focuses in particular on the barriers to adopting nitrogen management practices,and how the concept of “farm systems” can be used to complement the large body of existing research based on diffusion of innovation.