Four-Year Field Study: Increased Yields in Soils Amended with Biochar from Sugarcane Residues
摘要
Surplus sugarcane bagasse and leaf field residue remain untapped resources associated with sugarcane processing and harvesting. Their pyrolysis produces biochar which can be land applied to improve soil health and crop performance. Biochar produced from field residue and sugarcane bagasse was applied once at either 0.80 Mg ha−1 (LB1, BB1) or 1.60 Mg ha−1 (LB2, BB2) to sugarcane, as single amendment or in combination with fly ash at 0.63 or 1.26 Mg ha−1. Through their high content in organic matter, fixed carbon and H:C ratio (68.8%, 64%, 0.48 and 71.1%, 60%, 0.46 for BB and LB, respectively), biochar helped build soil organic carbon and increased the permanent carbon pool in the soil. HoCP 96-540 cane yield, theoretical recoverable sucrose, and sugar yield were measured and compared across treatments for 4 years. Biochar treatments led to improvements to crop performance, albeit some were not significantly different than the control. No reductions in sugar yield were observed for FA additions. Best results were determined for field application of LB1 followed by BB2, specifically with 0.90 and 0.88 kg/stalk, cane yield of 85.8 and 83.3 Mg ha−1, sucrose yield of 8647 and 8210 kg ha−1, respectively, when compared to control at 0.78 kg/stalk, cane yield of 68.3 Mg ha−1, and sucrose yield of 6566 kg ha−1. Considering the cumulative sugar yield over 4 years, additional income can be realized from amending soil with biochar. Best outcome resulted in estimated sugar profits up to additional $6837 ha−1 for LB1 (raw sugar at $0.82 kg−1).