Wood ash effect on chemical and microbiological properties of topsoil in a Norway spruce stand one year after the treatment

Abstract

Changes of soil chemical and microbial characteristics in the forest floor and in the A-horizon caused by the application of wood ash (WA) on the soil surface were studied one year after the WA application. Soil sampling was performed at three plots in a 40-year-old Norway spruce stand in Central Slovakia – at the control plot (CP) and at the plots with WA application in the spring (P1) and the autumn (P2) 2010. Soil samples were taken from the litter (L), fermentation (F), humic (H) forest floor horizons and from the A-horizon (the depth of 0−10 cm). In soil samples chemical attributes (pH, C and N concentration, extractable C and base cations concentration) as well as microbial characteristics (microbial biomass C, basal respiration, catalase activity, richness and diversity of soil microbial functional groups) were analysed. WA application was reflected in the changes of chemical properties (soil reaction, C, N and Ca2+ concentration) only in the forest floor horizons but not in the A-horizon one year after the treatment. No significant differences between plots were found in microbial characteristics throughout the topsoil horizons. The most distinct differences in decreased C and N content compared to control plot were observed in the H-horizon. Soil acidity differed especially in the F-horizon, where the increase of pH-H2O from 4.76 to 6.85 at P1 was recorded.