BIOCHEMICAL-CHARACTERIZATION OF BIOLOGICAL-ACTIVITY IN VERY YOUNG MINE SOILS

A number of biochemical parameters reflecting biological activity (respiration, ATP, enzyme activities) were determined in 0- to 7-year-old lignite mine soils. C (as CO2) and ATP contents, and hydrolytic enzyme activities all increased with soil age. The kinetics of CO2 release showed that both labile and recalcitrant C-bearing substrates were mineralized, the mineralization constant of C decreased with soil age, but were always greater than those of native soils. The percentage of N mineralization, which tended to decrease with soil age, resulted in all cases in a predominance of ammoniacal forms. These findings suggest that since organic C and N accumulated with age in these soils, the C and N cycle is established progressively.