When considering variable-rate nitrogen or seed application, soil sampling can provide farmers and their consultants with valuable information about the spatial distributions of soil properties such as organic matter, micro- and macro-nutrients, and pH. Conceptually, that information may be especially valuable for site-specific input management. But just as farmers make decisions about input applications, they also must make decisions about soil sampling, and in particular, must choose soil sampling density. It is standard practice for U.S. corn and soybean farmers to take soil samples on their fields every three or four years at a density of one sample per 2.5 acres. But whether that 2.5-acre density is economically optimal, and how the optimal density might change under different field and weather situations is largely unknown. Some producers choose one sample per acre and others choose one sample per ten acres. This article aims to present an analytical microeconomic framework to help non-economists systematically address these economic questions