Effects of rotational tillage on soil physical properties and winter wheat yield

Conservation tillage in Northern China was very common. However, many problems occurred for winter wheat fields with long-term no tillage, which was not favorable to winter wheat growth. In order to solve those problems, rotational tillage was introduced in this study. Rotational tillages were conducted in the winter wheat field with five years no-tillage under the wheat/corn double-cropping system. Treatments were NT (NT-NT), CT (NT-CT) and RT (NT-RT), respectively. The treatments were cultivated before sowing the winter wheat. Results showed as follows: Rotational tillages (CT, RT) after long-term no tillage significantly reduced soil bulk density; RT significantly reduced the soil bulk density at 0-10 cm layer While CT decreased at 0-20 cm soil layer. Differences of bulk density decreased with the growth of winter wheat. Rotational tillages significantly increased the soil total porosity at 0-10 cm layer, while CT significantly increased at the 10-20 cm soil layer. CT and RT increased soil capillary porosity at 5-10 cm layer. The soil saturated hydraulic conductivity at 0-10 cm soil layer was significantly higher for CT and RT than that for NT at 5% level, while that from the highest to the lowest were CT, RT, NT at 10-20 and 20-30 cm soil layers. And the soil saturated hydraulic conductivity of CT at 10-20 cm soil layer was significantly higher than NT at 5% level. The soil saturated hydraulic conductivity showed a significant negative linear correlation with soil bulk density. Rotational tillages significantly increased the effective panicle number and it was 24.1% higher in CT, 22.3% higher in RT compared with the NT. Yields from the highest to the lowest were RT, CT, NT. The yield of winter wheat was 11.8% higher in CT, 16.9% higher in RT compared with the NT treatment. After long-term no-tillage soil tillage can improve soil physical properties and increase crop yield.