Influence of xenobiotic perturberation on soil mcrobial community

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.