Research Journal of Agricultural Science, 43 (3), 2011 206 TILLAGE PRACTICES AND THEIR INFLUENCE ON SOIL PHYSICAL CHARACTERISTICS IN SOUTH-WEST OF SLOVAKIA Jozef SMATANA, Milan MACÁK, Eva DEMJANOVÁ, Nora SMATANOVÁ Faculty of Agrobiology and Food Resources, Slovak Agricultural University in Nitra, Tr. A. Hlinku 2, 949 76 Nitra, Slovak Republic E-mail: jozef.smatana@uniag.sk Abstract: The field experiments was carried out over the period of 2004 - 2007 at the experimental farm Kalná nad Hronom in south-western Slovakia. The aim of the research was to evaluate the influence of conventional and reduced tillage and management of organic matter on the soil physical characteristics. The sugar beet - spring barley – sunflower - winter wheat crop sequence was evaluated. The soil tillage treatments as follows: T1 - conventional mould board ploughing with farm yard manure application to sugar beet and incorporation of post harvested residues of spring barley and sunflower; T2 - convnentional mould board ploughing; T3 - no-till Horsch CONCORD CO 9. During June soil samples were taken from 0.05 - 0.10 m, 0.10 - 0.20 m, 0.20 - 0.30 m. Total porosity, soil bulk density and soil moisture was evaluated. The differences between soil layer and crops growing in different years were ascertained. Evaluated tillage treatments have no statistical influence on total porosity and soil bulk density in an average of four years. No till treatment (T3) influenced the less infiltration rate of soil profile with comparison to mouldboard ploughing treatments. The soil bulk density was highly significantly influenced by weather condition, growing crops and residue management and significantly influenced by soil layer. The positive effect of FYM on total porosity was evaluated in 2004 during sugar beet phase of rotation in first and second soil layers 0.05 - 0.10 m (T1 47.47 %) and 0.10 - 0.20 m (46.93 %) which is in relationship with soil bulk density 1.266 t.m 3 and 1.279 t.m 3 in topsoil layers 0.5 - 0.20 m. Soil bulk density range from 1.361 - 1.52 t.m 3 , in an average. Average data of total porosity revealed the significant less total porosity in deeper soil layer 0.2 - 0.3 m (41.65 %) with comparison to top layer 0.05 - 0.10 m (44.5 %). Significantly less total porosity was created under canopy of sunflower (39.9 %) with comparison to sugar beet (43.3 %), spring barley (43.8 %) and winter wheat (45.1 %). In four year average results, the conventional mould board ploughing with farm yard manure form the most suitable soil environment (soil bulk density, total porosity and soil humidity retention), but we also recommended no-till for this specific area of Slovak region. Key words: conventional tillage, no-till, soil bulk density, total porosity, soil moisture, crop rotation INTRODUCTION On the soil management changes have a major effect soil water, heat, nutrition regimes, tillage management and climate conditions. The aimed tillage habitat management is crucial part of sustainable farming (HUSNJAK et al., 2002). The increasing of soil density is implemented by self-weight of soil or it is caused by intensive rainfalls during a growing season. In winter time the changes of soil bulk density (SBD) are activated by the ploughing effect of winter frosts (FRANZLUEBBERS, 2002). The SBD and total porosity is considered to be an integral indicator of the soil habitat quality (LOGSDON and KARLEN, 2004). The importance and influence of tillage systems on physical characteristics is broadly recognized (BIRKÁS et al., 2008; BOJA et al., 2008). The aim of this study was to evaluate the influence of tillage practices (conventional and reduced) and organic matter management on the soil physical characteristics.