Impact of tillage on physical characteristics in a Mollisol of Northeast China.

Soil management is aimed at the maintenance of optimal soil physical quality for crop production. In order to explore the effects of tillage practices on soil physical properties, a study was conducted to compare the effects of no tillage (NT), moldboard plow (MP) and ridge tillage (RT) on soil bulk density (BD), soil penetration resistance (SPR), soil water content (SWC), soil macroporosity (MAC) and soil air-filled porosity (AFP) in Northeast China. Results showed that both NT and RT led to significant BD increment than MP at 0-20 cm (P < 0.05). Compared with MP, NT and RT increased SPR at the depths of 2.5-17.5 cm (P < 0.05). SWC of 0-10 cm layer was significantly higher in NT and RT than MP soils (P < 0.05). NT showed a significantly lower MAC than MP and RT at 0-20 cm soil depths (P < 0.05). All AFP values were above the limit of 0.10 cm(3)/cm(3) under all tillage treatments. RT improved the soil physical quality as evidenced by decreased BD and SPR, and increased SWC, MAC and AFP relative to NT.