SHORT ROTATION WOODY CROPS FOR FLORIDA a

Abstract

Florida’s long growing season and abundant moisture results in highly productive short rotation woody crops (SRWC). Potential oven-dry annual yields of promising species are: 19.9 Mg ha -1 yr -1 (8.9 ton a -1 ) for cottonwood (Populus deltoides), 23.1 Mg ha -1 (10.3 ton a -1 ) for closely-spaced slash pine (Pinus elliottii), 31.4 Mg ha -1 (14.0 ton a -1 ) for leucaena (Leucaena leucocephala (Lam.)), 66.6 Mg ha -1 (29.7 ton a -1 ) for castor bean (Rininus communis), 25.1 Mg ha -1 (11.2 ton a -1 ) for intensively managed Eucalyptus amplifolia in north Florida, and 36.1 Mg ha -1 (16.1 ton a -1 ) for E. grandis in central and south Florida. Flatwoods soils and reclaimed phosphate land are well suited to growing short rotation woody crops (SRWC). Thousands of acres of land, with low opportunity costs of $37.06 to $61.78 ha -1 yr -1 ($15 to $25 a -1 yr -1 ) in central and parts of south Florida, and $86.48 to $160.62 ha -1 yr -1 ($35 to $65 a -1 yr -1 ) in the north and west Florida are potentially available. One potential use for SRWCs is co-firing with coal in existing power plants. A recently completed feasibility study at Lakeland Electric, estimated costs, including production, harvest and transportation, of $1.76 per mm Btu for E. grandis and $1.73 for leucaena. Harvest costs were estimated to be more than 70% of total cost with feller-buncher technology on Eucalyptus and almost 50% with a high capacity forage harvester (eg. Claas) on leucaena. Successful test burns were completed at Lakeland Electric’s McIntosh Plant and at Tampa Electric’s (TECO) Gannon Plant. Both plants are now permitted to continuously co-fire biomass with coal.