A series of fishkills in 1997 in the Chesapeake Bay were linked to Pfiesteria piscicida, a rare toxic microorganism, and to nutrient pollution from agricultural sources. Manure from poultry production on the Delmarva Peninsula was regarded as the primary source of the excess nutrients. These fishkills served as a focusing event for policy-makers in Maryland, Virginia, and Delaware to update their scientific guidance on phosphorus management, promulgate agricultural regulations, and depart from decades of relying on voluntary technical and financial assistance to improve farm-related water quality problems.

This dissertation conducts a comparative case study of these three states to determine if 1) the policy-making process in each state affects compliance by farmers and 2) if the laws improved farmer nutrient management behavior. Data sources include information gathered from interviews with 60 corn farmers on the Peninsula that use broiler chicken manure as fertilizer; interviews with over 60 policy stakeholders; and reviews of primary and secondary documents. Analytical methods include: political analysis of the main stages of the policy development process; policy analysis of the effectiveness of plan-based regulations; statistical tests to determine significant differences between states regarding farmer responses to Likert Opinion Statements and questions about their nutrient management practices; logit regression analysis to determine factors influential to low manure application rates; and a review of compliance data collected by the state regulatory agencies.

Answers to both research questions are, overall, "yes," though this answer depends on which dataset of compliance and which metric of improved nutrient management behavior is reviewed; there are "no" answers as well. Results of this dissertation highlight the serious difficulty of regulating dispersed nonpoint source agricultural nutrient pollution through nutrient management plans. Several findings arise, including: plan-based agricultural regulations are in reality voluntary; plans prepared by private and public sector planners result in non-uniform standards; gaining "buy-in" from rather than "alienating" the regulated community likely results in better overall outcomes; regulations that account for on-the-ground realities of farming and state regulatory capacity likely achieve better overall outcomes; and focusing events that turn out to be weak can undermine the justification for new regulatory policies.