EN
In a field experiment, the influence of the kinds and of the seasons of the application of sludge, as well as of the mineral fertilization, on the content of nitrogen, phosphorus and potassium in potato tubers as well as on the grain and straw of oats and winter rye was investigated. The influence of the parameters investigated on the values of the utilization coefficient of nitrogen phosphorus and potassium from organic fertilizers was also determined. The influence of all the parameters investigated on the content of the macroelements determined in the crops tested was stated. The parameters investigated also differentiated the values of the utilization coefficient of nitrogen, phosphorus and potassium from farmyard manure and waste activated sludge.