Systematic examinations of the soil in the static experiments carried out from 1974 by IHAR, Jadwisin Division, with respect to such parameters as pH, the content of available forms of phosphorus, potassium and magnesium, as well as some microelements (boron, zinc, manganese, copper), showed that common potato soils require systematic organic and mineral fertilisation as well as liming in order to maintain high productivity. The results obtained in 1997, after 15 years (from the time of last examinations in 1982) constitute the evidence supporting the above conclusion. For example pH in KCI increased from 5.61 to 5.94, the content of phosphorus, respectively, from 15.67 to 23.63 mg, potassium from 14.46 to 17.36 mg and magnesium from 3.66 to 7.25 mg/100 g of the soil and the content of microelements increased as follows: boron from 0.23 to 0.46 ppm, zinc from 4.86 to 5.63 ppm, manganese from 274.40 to 137.53 ppm in the soil.