Biochar application is strategic to improve soil quality and productivity. However, the effects of biochar produced from sewage sludge with cashew pruning biomass; and cashew bagasse on the physical attributes of degraded soils in arid regions remain unclear. The hypotheses were: (1) biochars from the co-pyrolysis of sewage sludge and cashew pruning (SSPB) and cashew bagasse (CBB) improve the physical quality of degraded soil and maize growth; (2) SSPB, richer in nutrients, facilitates better maize growth compared to CBB; (3) for each biochar, there is an optimal rate to improve soil physical quality and maize growth. We collected samples in the 0-10 cm layer of a Planosol from a desertification nucleus. The experiment was conducted in a greenhouse with a completely randomized design in a factorial scheme 2 x 4 + 1 (two biochars: SSPB and CBB; four doses: 5, 10, 20, and 40 Mg ha(-)1; and a control), totaling 36 experimental units. Water demand, plant development, and soil physical attributes were assessed. During incubation, SSPB at 5 and 10 Mg ha(-)1 reduced available water capacity (AWC) by 25% compared to the control. In post-cultivation, SSPB reduced penetration resistance and increased aggregate stability. CBB increased AWC by 30% and reduced water demand by 40% at 9 Mg ha(-)1. SSPB reduced bulk density by 4% at 22.6 Mg ha(-)1. SSPB improved soil physical quality significantly, while CBB optimized water use efficiency. Recommended doses are 20-25 Mg ha(-)1 for SSPB and 9 Mg ha(-)1 for CBB.