Which management practices farmers adopt has a significant effect on agricultural pollution. Research has analyzed factors influencing adoption of a single management practice. But often adoption decisions about many practices are made simultaneously, which suggests use of a polychotomous-choice model to analyze decisions. We apply such a model to the choice of alternative management practices on cropland in the Central Nebraska Basin and control for self-selection and the interaction among alternative practices. We use the results of the choice model to estimate the economic and environmental effect so adopting alternative combinations of management practices. Our results suggest that crop rotation and soil N testing are complementary practices, perhaps because soil N testing enables farmers to properly credit eh N fixed by legume crops. As a result, farmers who adopted both rotation and soil N testing achieved greater profits from corn production while decreasing N fertilizer use than farmers who only adopted one of the practices. Also, farmers who adopted both rotation and soil N testing achieved greater profits from corn production while decreasing N fertilizer use than farmers who only adopted one of the practices. Also, farmers who adopted both conservation tillage and crop rotation reduce their average soil erosion rates, but not their N fertilizer rate, as compared with farmers who adopted only one of the practices. Our findings demonstrate the importance of conducting joint analysis of alternative farm management practices.