The effects of various tillage treatments on soil physical properties, earthworm abundance and crop yield in Hungary

Historically, tillage has been essential for seedbed preparation and weed control, but it has also accelerated soil degradation through erosion and loss of soil organic matter (SOM). Our objective was to quantify the changes in soil physical properties and earthworm abundance under six tillage treatments on an Endocalcic Chemozem (Loamic) soil (2016 and 2017). The long-term tillage experiment was set up in 2002 with the following tillage treatments: disking 12 to 14 cm deep (D); shallow tine cultivation (18 to 20 cm) (SC); no-tillage (NT); deep tine cultivation (22 to 25 cm) (DC); loosening to a depth of 40 to 45 cm (L); moldboard ploughing to a depth of 28 to 30 cm, followed by leveling (P). Soil samples were collected in the autumn of 2015 from four depth increments (0-10, 10-20, 20-30, 30-40 cm). Soil moisture content (SMC), soil penetration resistance (SPR), soil texture, pH (H2O), soil organic carbon (SOC), and earthworm abundance were measured. SMC and SPR were taken at 30-day intervals unless the weather prevented sampling. Earthworms were sampled in situ seven times per year by handsorting 25 x 25 x 30 cm soil blocks. No-tillage had a positive effect on crop yield and earthworm abundance. Compared to conventional tillage (P), SMC and SPR were improved by conservation tillage (DC, SC, D or NT). When measured during the summer months, SPR reached 6 MPa for all tillage treatments due to low SMC. Overall, NT had the highest earthworm abundance while conventional tillage (P) had the lowest. Maize (Zea mays L.) yield was highest with SC (9.32 Mg ha(-1)), lowest with D (7.92 Mg ha(-1)). For winter oat (Avena fatua L.), L resulted in the highest yield (5.87 Mg ha(-1)) but required more time and energy. As weather patterns become more erratic, tillage has the potential to make crop production even riskier. Therefore, to improve both physical and biological soil properties, efforts should be made to decrease tillage intensity each year.