D. Terziyski, L. Hadjinikolova

Abstract. The aim of this study is related with the characterization of the chemical parameters of sediments obtained from intensive carp ponds, as a natural biological product. Vertical differentiation in the levels of the studied chemical indicators of sediments was established. At 0–15 cm horizon the active reaction values were between 2% and 6% higher, the content of organic nitrogen was on average 47.95% higher, and that of ammonium and nitrate ions on average 34% – 37.85% higher, comparing with the recorded for 15 –30 cm horizon. At 15–30 cm horizon the organic matter content was on average 30.4% higher, that of phosphate ions with 13.1% higher, comparing to this of 0 –15 cm horizon.