No-tillage with Stubble Mulching Enhances Soil Physical Properties and Reduces Soil Penetration Resistance: A Comparative Study in Mollisol Region of Northeast China

Abstract. The mollisol region of Northeast China constitutes a critical grain production base. However, prolonged intensive farming has disrupted native soil structures, driving soil degradation and generating excessive crop residues that constrain sustainable agricultural development. To address these challenges, a field experiment evaluated four mechanized tillage-sowing practices: Plow Tillage with Precise Sowing (PTS), Rotary Tillage with Precise Sowing (RTS), No-Tillage Sowing (NTS), and No-Tillage with Stubble Mulching and Sowing (NTMS). This study systematically assessed the impacts of these practices on soil compaction through analysis of soil penetration resistance (SPR), while further examining their effects on soil water content (SWC) and soil bulk density (SBD). Results demonstrated that NTMS significantly increased SWC, whereas NTS resulted in higher SBD and SPR than other practices. Both PTS and RTS improved SWC relative to NTS and reduced SBD more effectively than NTS or NTMS. Across all practices, SPR exhibited consistent trends during the soybean growth cycle, peaking at the podding stage. NTMS outperformed alternative practices by optimizing soil physical properties, thereby enhancing soil quality and slowing degradation processes in the black soil. Collectively, NTMS implemented within a maize-soybean rotation system offers a viable solution to address maize straw surplus and soil degradation in Northeast China's mollisol region.