The aim of the present research started in 1977 as a lysimetric experiment in the Institute of Soil Science and Plant Cultivation in Puławy, was, among others, determination of the leaching dynamics for plant nutrients as related to type of soil and level of NPK fertilization. To this end, determination of soil water balance, changes in the chemical composition of the lysimetric filtrates and level of ion leaching during consecutive months and years of the experiment. In the conditions of the present lysimetric experiment, effects of season, type of soil and plants on the amount of filtrates collected was observed. Nitrate concentration in the filtrates was related to the kind of soil, its utilization and fertilization level. Nitrate concentration in the water percolating through the fallow soil, particulary loess and loamy soils, was usually higher than the water from the cultivated soils. There was no effect (similarly to the previous years) of the fertilization level on the nitrate ions losses from the soil. The highest amount of nitrogen was lost from the fallow soil (the mean of 9.3-14.2 g m^–2 year^–1).