Since the early 1970's, soil nitrate nitrogen (NO3-N) levels have been used as a basis for N fertilizer recommendations in western Canada. However, soil nitrate N does not represent the supplying power of soil N for plant uptake. Furthermore, the nitrate concentration in soil changes depending on the time and ambient conditions at sampling. Researchers in the past have used mineralization potential to predict N supply power for plant growth. There are two methods to estimate the potential mineralizable N: a laboratory incubation and a chemical extraction method. The laboratory incubation method requires a long time to obtain a measurement. By comparison the chemical extraction method (e.g., hot KCl extraction) provides a quick estimation of potential mineralizable N, but the method requires calibration with laboratory incubation results. Alberta Agriculture, Food and Rural Development has established benchmark sites to monitor soil property changes from agricultural practices. Hot KCl extractable N and so...