Biochar Application to Recover Degraded Soils: Comparison of Different Biomass Sources Assessed by Soil Physical Quality and Maize Growth
摘要
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 × 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.