Improved sugar yields found by application of bagasse and leaf residue biochar as soil amendment

Authors: Lima, Isabel; White, Paul

Submitted to: Sugar Journal
Publication Type: Trade Journal
Publication Acceptance Date: 12/28/2019
Publication Date: 1/1/2020
Citation: Lima, I.M., White Jr, P.M. 2020. Improved sugar yields found by application of bagasse and leaf residue biochar as soil amendment. Sugar Journal. 82(8):12-17.

Interpretive Summary: Sugarcane trash and bagasse represent potential untapped resources associated with harvesting and processing of sugarcane. Transformed into biochars to use in sugarcane fields for improved sugarcane yields, while enhancing soil health and water holding capacity. Biochars were produced from sugarcane leaf residue and bagasse and applied at 0, 4 and 8%, with and without fertilizer. Sugarcane biomass and sugar content of the cane stalk were compared across different treatments. Adding biochar to the soil consistently resulted in increases in stalk cane yield and sugar yields. Yield increases were more significant with bagasse than leaf residue biochar and more significant with 4% than 8% biochar addition. Best results found with 4% bagasse biochar addition and a sugar content improvement of 22.3% and 31.6% from control, for fertilizer and no fertilizer additions, respectively. Increase of carbon and nutrients in soil as well as improved soil drainage and aeration are potential benefits of adding biochar to cane fields. Additional economic benefits are expected for both sugarcane growers and processors through the production of valuable biochar together with enhancing the sugarcane industry’s footprint in renewable energy markets.

Technical Abstract: Sugarcane trash and bagasse represent potential untapped resources associated with harvesting and processing of sugarcane. These organic feedstocks can be thermo-chemically converted into biochars and brought back to the field as soil amendments to improve sugarcane yields, while enhancing soil health and water holding capacity. Biochars from sugarcane leaf residue and bagasse were applied at 0, 4 and 8%, with and without fertilizer. Sugarcane biomass and theoretical recoverable sucrose (TRS) content were compared across different treatments. Adding biochar to the soil consistently resulted in improvements in total TRS, stalk cane yield and sugar yields. Yield increases were more significant with bagasse than leaf residue biochar and more significant with 4% than 8% biochar addition. Best results found with 4% bagasse biochar addition and a TRS improvement of 22.3% and 31.6% from control, for fertilizer and no fertilizer additions, respectively. Benefits of biochar application to cane fields include increases in soil carbon, improvement to soil drainage and aeration, and addition of nutrients for the sugarcane crop. Economic benefits are expected for sugarcane growers and processors through the production of valuable biochar from sugarcane leaf residues and bagasse together with enhancing the sugarcane industry’s footprint in renewable energy markets.