Background Biochar, produced through biomass pyrolysis, has been proposed as a strategy for the restoration of degraded dry soils due to its stability and potential benefits. However, knowledge about its impact on the physical structure of degraded drylands remains limited, particularly for biochars derived from co-pyrolysis of sewage sludge with cashew residues.Aims This study evaluated the effects of two biochars applied at distinct rates on the physical properties of a degraded loamy sand soil.Methods A column experiment was conducted in a greenhouse under a completely randomized design (2 & times; 4 + 1) with four replications. Treatments included two biochars obtained from the co-pyrolysis of sewage sludge with cashew pruning residue (SPB) and the pyrolysis of cashew bagasse (CBB), applied at four rates (5, 10, 20, and 40 Mg ha-1), along with a control. Soil density, porosity components, pore size distribution curves, air permeability, pore continuity index, and aggregate stability were analyzed.Results The application of SPB at 20 Mg ha-1 reduced bulk density by 7.74% compared to the control. Porosity components and pore connectivity were primarily influenced by soil reconsolidation over time, with only isolated and inconsistent effects of SPB and CBB. Aggregate size distribution was more responsive: SPB favored larger aggregates, whereas CBB promoted smaller ones.Conclusions Overall, the results indicate that biochar additions can affect specific aspects of soil structural quality, but their impacts are context-dependent and not uniformly expressed across physical attributes.