A method for application of an agricultural product to a field is provided. The method includes acquiring real-time sampled data using real-time agricultural sensors, auto-calibrating the real-time agricultural sensors using statistical characteristics of the real-time sampled data to determine an application rate, and applying the agricultural product to the field based on the application rate. The step of auto-calibrating can be performed in various ways depending upon the type of agricultural product, the data available from the agricultural sensors or otherwise, or otherwise.