Fig. 2. Nitrogen mineralization rates and technique comparison conducted between 3 May and 5 June 2000 for the N-fertilized and N-unfertilized, chisel-plowed (CP), and no-tillage (NT) corn treatments. Asterisks denote significant differences (** = p < 0.05 and *** = p < 0.001) in N mineralization estimates from the same method [i.e., incubated soil core–ion exchange resin bag (ISC–IERB) or minilysimeter] between N-fertilized and N-unfertilized treatments. Least significant differences ( = 0.05 level) between methods were 12.5 and 20.3 kg N ha^-1 mo^-1 for the N-unfertilized (p = 0.114) and N-fertilized (p = 0.521) CP treatments, respectively.