Sugarcane Biomass, Dry Matter, and Sucrose Availability and Variability When Grown on a Bioenergy Feedstock Production Cycle

Abstract

Sugarcane grows on over 170,000 ha in the state of Louisiana as part of a sugar industry that generates over $2 billion in annual economic impact. The multipurpose crop produces sugar, molasses, bagasse, boiler fly ash, filter press mud, water, and electricity. As a component of a theoretical bioenergy economy, bagasse and sugarcane itself may find a value-added niche as a renewable feedstock source. The objectives were to characterize yields of ‘Ho 02-113’ at two locations over 2 years and compare two harvest strategies, green-cane harvest (stalks-only), or complete biomass harvest (intact plants). The first- and second-ratoon crop and the plant-cane and first-ratoon crop were harvested monthly at the Ardoyne Farm or Spanish Trail, respectively. Total biomass yields of 120 Mg ha−1 and up to 35 Mg dry matter (DM) ha−1 at the Ardoyne Farm and total biomass > 140 Mg ha−1 and 50 Mg DM ha−1 at Spanish Trail were observed. Sucrose levels ranging from 2000 to 8000 kg ha−1 were recorded between August and September of each year. However, freezing conditions rapidly reduced sucrose levels from as high as 12,000 kg ha−1 to below detection limits within 60 days. Dry matter energy content of intact plants, stalks, and dry leaves was 17.0, 17.4, and 16.5 kJ g−1, respectively. The overall energy yields were 530 and 620 GJ ha−1 for the Ardoyne Farm and Spanish Trail, respectively. Results demonstrate that Ho 02-113 is a versatile feedstock and can meet sucrose and/or lignocellulosic feedstock needs in areas with temperate to subtropical temperatures.