Changes of the chemical composition of bottom sediments in a dystrophic Lake Smolak twenty years after the end of a liming and mineral fertilisation experiment

Abstract

Bottom sediments of Smolak Lake twenty years after the end of liming and mineral fertilisation experiment contained 59-84% of organic matter, 14-55% of silica, 0.05-1.8% CaO, 0.1-0.7% Fe₂0₃, and 0.1-0.5% P₂0₃. Organic mater content increased by 26%, P₂0₃ - 28%, CaO content decreased by 24%, and Fe₂0₃ - 74% compared to the period immediately post mineral fertilisation and liming (1975). Phosphorus and iron accumulated in surface layer (0-5 cm), and calcium in deeper layers of the sediments (26-40 cm).