Despite the intuitive appeal of precision farming, adoption of precision technology options has been well below expectations. A review of precision farming studies suggests as expected that precision farming becomes more profitable as in-field spatial variability increases. However, no studies have attempted to quantify infield variability at any reasonable scale beyond a few experimental fields. This study contributes to the assessment of precision farming by introducing an approach that can help characterize the relative profitability of precision farming methods as compared to conventional farming. Using readily available geographic information systems databases on crop cover, soil type, and weather, we use a fully-linked biophysical-economic modeling system to assess the viability of precision nitrogen applications on corn in Livingston County, Illinois. Livingston County was selected because of its role as a major corn producing county in Illinois. We find little evidence, in general, for viability of precision nitrogen applications in contrast to uniform application rates, largely because of the lack of significant in-field spatial variability in soil types. However, precision application methods may be viable in specific situations.