Strip tillage combines the characteristics of conventional tillage and no-tillage in terms of soil macropore structures and hydrothermal conditions

Achieving sustainable utilization of black soils in Northeast China hinges on balancing exploitation and conservation. Conventional tillage (CT) degrades soil over time, while no-tillage (NT) conserves soil but often reduces yields. Strip tillage (ST) tills within the seed row zone (ST-IR) while maintains NT with straw mulch between seed rows zone (ST-BR), which appears to integrate the advantages of CT and NT. However, the effects of ST-IR and ST-BR on the soil macropore structures and hydrothermal properties in this region remain unclear. In this study, X-ray computed tomography (X-CT) and time domain reflectometry (TDR) were employed to compare the soil macropore characteristics and hydrothermal conditions across NT, CT, ST-IR, and ST-BR. Results showed that the soil hydrothermal conditions, bulk density (BD), penetration resistance (PR), air capacity (AC), air permeability (AP), and available water capacity (AWC) of ST-IR were similar to those of CT ( P > 0.05). However, the hydrothermal conditions of ST-BR resembled those of NT ( P > 0.05). Furthermore, ST created two distinct macropore structures. ST-IR aligned with CT in macropore size distribution, pore morphology, and connectivity ( P > 0.05), showing high macroporosity and connectivity. The macropores of ST-IR were dominated by irregular, large-volume non-biopores, with higher compactness (CP, 1978), specific surface area (SA, 0.50), and fractal dimension (FD, 2.62), yet lower degree of anisotropy (DA, 0.26). In contrast, ST-BR converged with NT ( P > 0.05), demonstrating significantly lower macroporosity and connectivity than ST-IR and CT ( P < 0.05). The dominant pore type in the ST-BR and NT consisted of tubular biopores, with CP (97), SA (0.11), and FD (2.38) all significantly lower than those in ST-IR and CT ( P < 0.05), while DA (0.42) was significantly higher ( P < 0.05). Overall, ST integrates CT and NT in soil macropore structure and hydrothermal conditions, offering valuable insights into its role in black soil conservation and utilization.