Investigation of the long-term effects of conservation tillage systems on the quality of clay-loamy soil in the Eastern Slovak Lowland

Understanding the factors influencing soil quality is essential for implementing sustainable management practices that ensure long-term agricultural productivity and ecosystem resilience. The four-crop rotation was established in 2005 at the experimental station of the Agroecology Research Institute in Slovakia, where the effects of conventional (CT) and conservation (reduced tillage – RT, and no tillage—NT) systems on the quality (physical, chemical, biological parameters) of clay-loamy soil (Gleyic Fluvisols) were compared. During the 2023–2025 study period, the research focused on two crops within the rotation, namely maize and soya. In topsoil, accumulation of soil organic carbon and nutrients was observed in conservation tillage systems. Reduced tillage alleviated soil compaction compared to conventional and no tillage. Soil acidity was significantly increased by no tillage. Conservation tillage systems promoted soil biological activity, doubling soil enzyme activity compared to conventional tillage. The mean Soil Quality Index (SQI) for reduced tillage represents a 25% improvement over the conventional system, achieving a “good” classification in soil quality index. Despite the positive effect of reduced tillage on soil quality, a 5–25% decrease in crop yields was observed. In conclusion, the results confirmed that long-term reduced tillage had a beneficial effect on the quality of clay-loamy soil.