Investigations on soil fertility in Poland have shown that in the period of 1965-1993 soil reaction changed slightly; there was some improvement in soil content of available phosphorus and potassium while available magnesium was decreasing seasonally. From among five micronutrients (B, Cu, Mn, Mo, Zn) the greatest share of Polish soils show B and Cu deficiency. Experiments carried out on regenerative fertilization of strongly exhausted soil have shown that parallel application of N, P, K, Ca and Mg is the most advisable whereas micronutrient fertilization is the matter of secondary importance.