Producers need to look at nitrogen recommendation in an objective manner.  Nitrogen recommendations that are economical and practical for today's producers need to be developed that work on a site-specific or a field specific basis.  With the majority of a corn crop's nitrogen being received from the soil and not the applied fertilizer we need recommendation and application methods that can take the soils N release into account. Once potential mineralization of N is predicted it can then be determined how to most efficiently supplement beyond what the soil is providing.   The Illinois Soil Nitrogen Test (ISNT) been shown to be very useful in constructing useful nitrogen recommendations.   A soil test that allows us to predict potential N release from the soil is useful in improving predictions of how much N needs to be applied to achieve economic optimum.  Because many factors affect release of N from the soil, it is important to use calibration data from fields and regions with similar management practices to those used in the fields the ISNT is being used on. Requirement for a successful soil test have not changed from those set forth by Roger Bray in 1948.  It is important to review how soil tests work so that the limitation of soil testing procedures can be understood.  Effective calibration to real field conditions will be important to ISNT and as it is to any effective soil test.