Potential leaching losses of nitrogen depend in large part on the crops grown. Since crop selection is a major means of abatement for nitrates in groundwater, it follows that the compliance costs to producers for reducing excess nitrogen is influenced by crop prices. This paper demonstrates the role that crop prices play in determining the level of on-farm abatement costs and even the necessity for regulatory policies to deal with the nitrate problem. Government support programs, specifically the Gross Revenue Insurance Program (GRIP), have increased the relative support for corn, which has higher leachate potential than other crops, and thereby requires increased abatement effort. The required level of abatement is less when risk aversion is considered than under risk neutrality, since the variability in returns among rotations is related to the degree of emissions generated. Changes in the mean and variance of relative output prices can significantly alter the optimal crop mix, leachate potential and onfarm abatement efforts. Subsequently, there is an effect on abatement costs associated with alternative environmental control instruments, which in turn affects policy design through issues such as political feasibility and equity considerations.