Biomass Composition and Mineral Removal of Sugarcane and Energy Cane on a Sand Soil in Florida.

Approximately 20% of Sugarcane is grown on sand soils in south Florida, but yields and profits are lower compared to sugarcane grown on organic soils in the region. Energy cane may be an alternative crop on sand soils in the future to improve profits because of the growing interest of increased biomass for energy. A field study was conducted on a sand soil in Clewiston, FL to determine biomass composition and mineral nutrient removal for sugarcane and energy cane. A commercial sugarcane cultivar CP 78-1628 and two energy cane cultivars (US 78-1013, US 84-1066) were planted in late October 2010. Data were collected on plant-cane, first-ratoon, and second-ratoon crops in 2011-2013. Above ground dry biomass (DBM), biomass composition, and mineral concentration were determined when plants reached maturity in December. Averaged across the three crops, energy cane had 26% higher DBM yield, 65% lower nonstructural carbohydrate (hexose and sucrose) concentrations, and significantly higher concentrations of cellulose, hemicelluloses and lignin in DBM than sugarcane. Compared to sugarcane, energy cane had significantly higher tissue concentrations of N, K, Ca, Mg, S, Si, Cu, Mn and B; but lower Zn. There were no differences between energy cane and sugarcane in tissue P and Fe concentrations. Due to the combine effect of higher DBM and higher concentrations in tissue, energy cane removed more N, K, Ca, Mg, S, Si, and Cu from the soil than sugarcane. These results indicated that there are significant differences between sugarcane and energy cane in carbohydrate accumulation and partitioning as well as mineral concentrations and uptake.