Abstract:
The effects of xenobiotics application on the composition and function of soil microbial
community were investigated in mountain grassland (Slovakia) and agricultural (UK)
soils. Slovak soil was Cambisol, sampled from the mountain grassland regions of
Greater Fatra, Lesser Fatra, Lower Tatras and Slovak Ore Moutains. UK soil was
sampled from the Cottenham, Faulkborne and Denchworth series located in an
agriculture farm at Silsoe. Soils thereby differed in climate conditions, soil type, soil
texture and land use. Initially soils were characterized by texture, moisture, pH, total
carbon, oxidizable carbon, total nitrogen, microbial biomass, hydrolytic enzyme
activity, soil respiration and PLFA composition. Results distinctly showed that the
microbial community structure, especially abundance of G+ , G- bacteria and fungi,
varied between different soil types.
An experiment was established using the UK soils. The effects of the xenobiotics
polyvinylalcohol, a fungicide (Fundazol) and a herbicide (Gesagard) on soil microbial
community and activity were investigated one day and forty-two days following
xenobiotic application. The functional stability in the terms of resistance and resilience
using the method described by Orwin and Wardle (2004) was calculated from the soil
respiration rate data. The experimental treatments caused a significant difference in the
PCA profile of PLFA data. Soil type and textural classification affected the altered
microbial profile. Treatments also altered microbial activity and microbial biomass. The
arable soils were more resistant to xenobiotic perturbation than grassland soils. The
reduction of functional stability was associated with the altered soil microbial
community composition. Thus, soil type had a greater role than treatment type in
determining microbial community composition whereas the treatment type was more
determining factor of catabolic profile.
