TILLAGE EFFECT ON SOIL QUALITY INDICATORS IN SLOVAKIA

In this study we compare some chemical and biological soil properties using the no tillage and conventional systems. In 2003 and 2004 the soil characteristics were observed on the precise field experiment plots in Borovce (near Piešťany, in the western part of the Slovak Republic) where no tillage management has taken place since 1995. The experimental plots were situated in the area where there is a continental character of weather (average annual temperature of 9.2 0C and the mean annual precipitation of 593 mm). A large variability of temperature and unequal precipitation are a characteristic of this area. The soil representative is loam and clay, loam degraded Chernozem on loess (pH 5.5 – 7.2, humus content 1.8 – 2.0 %, good available potassium store, medium phosphorus content and high magnesium content). The chemical and biological soil properties were determined within two farming systems: no tillage and conventional (mouldboard plough). The soil samples were taken four times during the vegetation period, from the depth of 0.02 – 0.2 m. The air dried soil samples were used for the chemical analysis (pH/KCl, Cox, Nt, Nin). The biological analyses were determined in the fresh soil samples. The results were statistically evaluated by the Wilcoxon pair test. The lower values of soil reaction and the higher contents of organic matter and inorganic nitrogen in the soil were measured under conventional treatment. No tillage management and the use of organic residues and compost also positively affected microbial biomass content, ammonification and nitrification activity. The earthworm population was more developed at the no tillage variant. During the years 2003 and 2004, after eight years of no tillage management utilisation, the tendency of increased biological activity in the soil under no tillage management was observed