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

A number of biochemical parameters reflecting biological activity (res piration, 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 s howed that both labile and recalcitrant C-bearing substrates were mine ralized, the mineralization constant of C decreased with soil age, but were always greater than those of native soils. The percentage of N m ineralization, which tended to decrease with soil age, resulted in all cases in a predominance of ammoniacal forms. These findings suggest t hat since organic C and N accumulated with age in these soils, the C a nd N cycle is established progressively.