Protease Activity of Forest Soils and their Responses to Phenolic Compounds in Soil

Abstract

Soil proteolytic complex plays an important role in nutrient cycling in the ecosystem. Interaction of this enzyme complex with phenolic acids was studied on selected soils. The aim was to determine how the soil protease reacts to the presence of phenolic compounds, i.e., substances released during the decomposition of organic matter and transferred to the soil environment. Phenolic compounds in organic horizon caused inhibition of soil protease, 4-hydroxybenzoic acid showed no statistical significance (P<0.05) in the spruce stand. Organomineral horizons responded as stimulants: ferulic acid acted as a stimulant in all measurements, while 4-hydroxybenzoic acid stimulated only with old deciduous stands. Mineral horizons reacted like organic horizons, namely as inhibitors, with the exception of ferulic acid which, in a young deciduous forest, did not show statistical significance.