Soil organic matter and basic physical parameters as indicators of the suitability of reduced and conventional tillage systems for three soil types in southwestern Slovakia, Central Europe

Purpose Because tillage systems can affect soil quality both positively and negatively, we investigated which physical and organic matter properties of Chernozems, Haplic Luvisols, and Mollic Fluvisols changed significantly after conversion from conventional tillage (CT) to reduced tillage (RT), and which system was more suitable for their management under Slovakian conditions in Central Europe. Methods The differences in soil properties between CT and RT were investigated on real farms at 15 sites to a depth of 40 cm. Results In Mollic Fluvisols with high soil organic matter (SOM) content, switching from CT to RT negatively affected only the physical properties in the 20–30 cm layer. Positive effects included statistically significant increases in organic carbon, humic acids (C HA ), and humic substances (C HS ) in the 0–10 cm layer, as well as in the degree of humification. Conversely, in soils with lower SOM contents (Haplic Luvisols and Chernozems), the conversion from CT to RT system caused a significant reduction in labile carbon, C HA , and C HS , along with a decrease in humus quality. The RT Chernozems showed a statistically significant deterioration in physical properties compared to CT. However, the Haplic Luvisols were compacted in both systems. Conclusion Considering the investigated soil properties under the given soil-climatic and agrotechnical conditions, CT appears to be more suitable than RT for the medium-textured Chernozems and Haplic Luvisols, while CT and RT were equally suitable for the Mollic Fluvisols. We confirmed the necessity to increase the SOM content to improve the soil properties under both tillage systems, especially under RT in Chernozems and Haplic Luvisols.