Soil water repellency (SWR) has significant effects on soil degradation by changing some soil processes (e.g., carbon sequestration and soil erosion). Understanding the influence factors of SWR under conservation agriculture are playing a vital role in the sustainable development for improving soil quality. However, how soil pore structure influence on SWR remains unclear. We aim to assess the impact of hydrophobic substances and pore structure on SWR. Here we conducted two long‐term experimental fields with three treatments: conventional tillage (CT), reduced tillage (RT), and no‐tillage (NT). X‐ray tomography and the sorptivity method were used to measure soil pore structure and SWR, respectively. We found that soil organic carbon (SOC) and microbial biomass carbon (MBC) were higher in RT and NT treatments than in CT. MBC had significant influences on soil water sorptivity (Sw) and water repellency index (RI; p < 0.001), whereas SOC had no influence on Sw (p > 0.05). MBC also showed a closer relationship with SWR than SOC in redundancy analysis. The RT and NT increased the porosity of 55–165 μm that had a positive relationship with ethanol sorptivity and RI (p < 0.05). Ethanol sorptivity increased with an increase in soil pore porosity and connectivity under RT and NT treatments. However, increasing the pore surface area could decrease Sw due to enhance contact area between hydrophobic substances and soil water. Overall, the RT and NT treatments increased the water repellency index, which was a result of the interactions between pore structure and hydrophobic substances.

No‐tillage (NT) has been shown to control soil degradation by impacting soil aggregates (i.e., basic units of soil structure, whose characteristics mediate key soil processes, like carbon sequestration). However, there has been no systematic analysis of the impacts of NT on soil aggregation and aggregate‐associated soil organic carbon (SOC) at global level. We conducted a global meta‐analysis of 89 publications to elucidate the changes in soil aggregation and aggregate‐associated SOC under NT. Notably, we quantified the roles of diverse environmental and agronomic factors (e.g., climatic conditions, experimental duration, cropping intensity, soil texture, and initial SOC/pH) in the changes in those variables. Relative to conventional tillage (CT), NT significantly increased the proportions of water‐stable large (LM) and small (SM) macro‐aggregates and the mean weight diameter (MWD) (by 49%, 11%, and 23%, respectively) but decreased the proportions of micro‐aggregates (MIC) and silt plus clay‐size particles (SC) (by 11% and 16%, respectively). NT significantly enhanced SOC concentrations in LM (17%), SM (14%), MIC (10%), and SC (7%) compared to CT. Furthermore, the random forest (RF) model demonstrated that climatic conditions, experimental duration, and soil texture were the predominant factors controlling the changes in aggregation and aggregate‐associated SOC under NT. Overall, our results indicate that NT is an effective strategy to enhance soil aggregation and aggregate‐associated SOC, yet variations in responses are determined by specific environmental/agronomic factors. This study provided a basis for identifying site‐specific NT practice that could help improve soil structure and SOC sequestration, ultimately controlling soil degradation in croplands.

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