Location: Sugarcane Research Unit
Title: Green-cane harvest of sugarcane effects on biomass and energy yields and nutrient removal Authors
Submitted to: Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: October 3, 2012
Publication Date: October 3, 2012
Citation: White Jr, P.M., Viator, R.P., Richard, E.P., Grisham, M.P. 2012. Green-cane harvest of sugarcane effects on biomass and energy yields and nutrient removal. In: Proceedings of Sun Grant National Conference: Science for Biomass Feedstock Production and Utilization, October 3 - 5, 2012. New Orleans, LA. Available: http://sungrant.tennessee.edu/NatConference/ Technical Abstract: Sugarcane yields in Louisiana can approach 40 dry Mg ha-1, making sugarcane an attractive biofuel feedstock as well as a profitable sugar crop. Existing technology used in green-cane harvesting can be used to allow chopper harvester extractor fans to remove variable amounts of extraneous leaf material from the cane stalk and deposit it on the soil surface during harvest. The objectives were to (1) evaluate biomass and energy yields of selected sugarcanes, (2) estimate residue nutrient losses, and (3) evaluate logistics of harvesting at different extractor fan speed settings simulating sugar or biomass harvest. A commercial sugarcane variety HoCP 96-540 and a high-fiber “energycane” variety L 79-1002 were planted in 2009 and the plant cane was harvested in Nov. 2010 and first stubble in Oct. 2011. Three fan speeds were used: (1) Optimal range of 750 rpm for sugar harvest; (2) Fans turned off to simulate biomass harvest; and (3) mid-range of 375 rpm to deposit some crop residue. For plant cane, L 79-1002 (38 dry Mg ha-1) produced more biomass than HoCP 96-540 (31-32 dry Mg ha-1). For first ratoon, the varieties produced the same biomass (32 dry Mg ha-1). Slowing or stopping extractor fans increased dry biomass yield by up to 13 Mg ha-1. However, turning off extractor fans increased nutrient removal from field by 9.6, 2.5, and 14 kg of N, P2O5, and K2O ha-1, respectively, when compared to the 750 rpm fan speed. The biomass harvest strategy with the harvester’s extractor fans turned off, designed to remove as much total biomass as possible, increased the number of cane wagon loads by a factor of 1.6, due to lower density of crop residue. Adoption of biomass harvest strategy using existing sugarcane harvest technology produced dry feedstock yields of 39 Mg ha-1, but the nutrient losses associated with residue removal may make lower yields more sustainable.