The aim of this research was to evaluate changes in soil quality associated with the tillage system applied with chosen parameters of soil biological properties. The long-term field experiments were located at a private farm in Rogów (Zamooeć region, E Poland) on a silt soil and at the Experimental Station in Laskowice (Wrocław region, S-W Poland) on a sandy loam soil. Soil samples were collected from 0-15 and 15-30 cm layers. Winter wheat was grown under traditional, reduced and no-tillage systems. The analyses included estimations of microbial biomass C and N content, microbial respiration rate, activity of dehydrogenase and arylsulfatase, and fluorescein diacetate hydrolysis. After eight years the effects of tillage on both soils were clearly noticed. In general, the less disturbing tillage systems enhanced the increase of soil biological activity by 15-40%, on average, than conventional tillage system. The significant correlations between microbial biomass, and/or enzyme activities with total organic C content indicate that concentration of organic C in soil environment plays an extremely important role in enhancing the stabilization and activity of soil microorganisms, and protection of an extracellular enzymes. The studied parameters of soil biological activity showed their sensitivity to tillage applied and may be considered as an useful indicators of soil quality in monitoring all conditions alter soil environment.

Soil biological activity as affected by tillage intensityThe effect of tillage intensity on changes of microbiological activity and content of particulate organic matter in soil under winter wheat duirng 3 years was studied. Microbial response related to the tillage-induced changes in soil determined on the content of biomass C and N, the rate of CO2evolution, B/F ratio, the activity of dehydrogenases, acid and alkaline phosphatases, soil C/N ratio and microbial biomass C/N ratio confirmed the high sensitivity of soil microbial populations to the tillage system applied. After three year studies, the direct sowing system enhanced the increase of labile fraction of organic matter content in soil. There were no significant changes in the labile fraction quantity observed in soil under conventional tillage. Similar response related to the tillage intensity was observed in particulate organic matter quantities expressed as a percentage of total organic matter in soil. A high correlation coefficients calculated between contents of soil microbial biomass C and N, particulate organic matter and potentially mineralizable N, and the obtained yields of winter wheat grown on experimental fields indicated on a high importance of biological quality of status of soil for agricultural crop production.