The availability of N to corn (Zea MaysL.) in soils previously amended with organic wastes was estimated by a number of chemical soil tests in 1982 and 1983. Availability indexes were correlated with yield and N uptake by the crop. Total soil N and June mineral N (N extracted by 2NKC1 from soil samples obtained when corn was 20 to 30 cm tall) proved to be good predictors of yield and N uptake for combined 1982 and 1983 data. Soil organic matter content and absorption of U.V. (260 nm) light by .01MNaHCO3and NH4OAc (pH 4.8) soil extracts were not well enough correlated with yield or N uptake to be useful in a soil testing program. Various combinations of log transformations of June mineral N, preplant mineral N, and Ap horizon depth proved to be good indexes of N availability and in some cases explained a significantly greater percentage of the variability in yield and N uptake than single‐variable indexes.