A mineral N content (N-min) in the 60-90 cm layer of mineral and org. soils depending on the N dose in the mineral fertilizer used for grassland as well as for the cultivation of maize and cereal mixes in 2010-2012 was detd. in spring and autumn to find a resp. correlation. The N-min content and the dose of N fertilizer were positively correlated for (i) grassland on mineral soils, (ii) grassland on org. soils, and (iii) cultivations of maize and cereal mixes on mineral soils. Particularly high correlation coeffs. (higher than 0.8) were obsd. for cereal mixes cultivations. A negative correlation was obsd. only for grassland on org. soils during the autumn sampling.