Sugarcane-bagasse and leaf-residue biochars as soil amendments for increased sugar and cane yields

Authors: Lima, Isabel; White, Paul

Submitted to: International Society of Sugar Cane Technologists Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 6/26/2019
Publication Date: 7/8/2019
Citation: Lima, I.M., White Jr, P.M. 2019. Sugarcane-bagasse and leaf-residue biochars as soil amendments for increased sugar and cane yields. Proceedings of XXX Congress of International Society of Sugar Cane Technologists. 30:844-850.

Interpretive Summary: 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 were 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.

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 were 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.