Long-term effects of tillage systems on soil health of a silt loam in Lower Austria

Tillage is an essential practice for soil preparation in agriculture that influences a broad variety of soil parameters. However, the long-term implications of tillage on soil health are complex, context specific, and need to be better understood. The aim of our study is to evaluate soil physical, chemical, and biological effects of three different tillage practices: conventional tillage (CT), mulch tillage (MT), and no-till (NT). A long-term experiment in Mistelbach, Lower Austria, was launched in 1994 and comprehensively sampled in 2002 and 2021. To evaluate tillage-impacts over the two decadal monitoring we assessed soil health indicators in the 0–20 cm soil depth (conventional ploughing layer) and below 20 cm. A "Soil Management Assessment Framework" (SMAF) procedure was applied to assess and compare soil quality using the Soil Quality Index (SQI). Considering multiple indicators, we found overall quality improvements in all three tillage-experiments over time. However, particularly the conservation practices (MT and NT) enhanced soil quality, predominately soil organic carbon (SOC) and soil physical indicators (e.g. water holding capacity, coarse pores). The study confirms that SOC in the 0–20 cm layer significantly increased under no-till (46 Mg C ha−1) compared to conventional tillage (26 Mg C ha−1). At the same time aggregate stability and water holding capacity increased under conservation agriculture (MT and NT). The proven positive impacts on soil health will further help to promote agricultural practices that sustain productivity while pushing forward climate change mitigation actions in temperate climate.