LAUSR

The aim of the study was to determine the effect of sewage sludge and composts produced from sewage sludge and municipal waste on the content of various forms of nitrogen in soil. The field experiment was carried out in 2004–2015. It included three crop rotations of the following plants: potato, spring barley, winter oilseed rape and winter wheat. The experiment consisted of the following treatments: control (without fertilization), NPK, manure (FYM), compost from municipal sewage sludge and straw (CSSS), composted sewage sludge (CSS), dried and granulated sewage sludge (DGSS), “Dano” compost produced from unsorted municipal waste (CUMW) and compost from municipal green waste (CMGW). Manure, composts and sewage sludge were applied once (10 t ha−1 of d.m.) or twice (5 t ha−1 of d.m.) in a crop rotation. It was significantly shown that the highest N-total content was in the soil fertilized with CUMW (compost produced from unsorted municipal waste). The soil fertilized with manure (FYM) contained the highest quantity of N-min. The prevalent pool of nitrogen (82.65–86.52%) consisted of N compounds not undergoing acid hydrolysis, and their smallest share was determined in the soil fertilized with NPK alone.