COMPOSITION OF FRESH, AEROBIC AND ANAEROBIC FARM ANIMAL DUNGS

Fresh cattle, pig and poultry excreta as well as aerobically and anaerobically decomposed materials of the same origin were analysed. Highest concentrations of plant nutrients were found in poultry excreta, followed by pig and cattle faeces. Calcium was the dominant element in the materials. Uric acid was the major nitrogen form in fresh poultry excreta (61%). Fresh cattle and pig faeces contained small amounts of ammonium N and traces of urea, but no nitrate. The main form of N in fresh and aerobic faeces was organic bound N. Low concentrations of nitrate (< 0.5% of total N) were indicative of aerobically treated materials, whereas high ammonium N concentrations (50-75% of total N) were typical for anaerobic materials. The C/N ratios increased during anaerobic decomposition in all materials.