Nitrogen Use Efficiency, Nitrogen Fertilizers, NUE, Nitrogen and the EnvironmentMESONET files
 
229L Calibration Details
Tomography of Soil-Water-Root Processes
Google Earth kmz file with Mesonet Site Locations
 
Link for computing cumulative GDD by ZIP Code
Link for computing Days, GDD>0

Calcuating GDD>0
Comprehensive information on Nitrogen Use Efficiency for cereal crop production