Impact of manganese, iron, and cobalt fractions on soil enzyme activities.

The goal of this study was to investigate the metal impact (Mn, Fe, Co) on enzymatic activities of soils cultivated using the simplified method, during spring, summer, and autumn. The distribution of studied metals between fractions was assesed according to the BCR method. Four fractions were evaluated: acid soluble and exchangeable (F1), reducible, which is bound to Fe/Mn oxides (F2), oxidizable, which is bound to organic matter (F3), and residual (F4). The highest Fe and Co percentage share was stated in fraction F4 (71.0 and 49.2%, respectively). The most of Mn gathered fraction F2 (50.8%). The lowest amount of Mn and Co was found in fraction F3 (13.6 and 17.7%, respectively) and for Fe, in fraction F1 (1.3%). In spring, the significant dependence was noted between F1/Mn/dehydrogenase, F3/Fe/dehydrogenase, F2/Co/dehydrogenase, and F4/Fe/protease. Such a relationship was found between F1/Mn/urease, F3/Fe/urease, F3/Co/urease, and F3/Co/phosphatase during autumn. During summer, F1/Fe caused an increase in phosphatase activity. [ABSTRACT FROM AUTHOR]