Biomass Production of Lignocellulosic Crops as Affected by the Number of Cuttings
The diversification of the energy matrix through biomass production is being evaluated in Uruguay. The species Arundo donax, Panicum virgatum and Pennisetum purpureum would be an option. The objective of this paper was to compare their biomass and energy production, with different cutting moments. The crops were planted in the spring of 2007 and evaluated from January 2012 to August 2013. Two harvest treatments were performed: cuts in January and August; and a single cut in August. Arundo donax produced 18.6 Mg ha-1 year-1 dry matter, more than P. virgatum and P. purpureum, which produced 15.0 and 14.6 Mg ha-1 year-1 dry matter, respectively. In A. donax and P. virgatum, the single cut treatment produced more than two cuts. In P. purpureum, the difference between treatments was significant in 2012, and the August cut produced more than the January cut. Arundo donax and P. purpureum presented higher ash contents, and the August values were lower than the January ones. In P. virgatum there were no differences between harvests. The highest energy production was achieved with A. donax (407 GJ ha-1 year-1) by harvesting it once. Panicum virgatum was the crop of the lowest energy production with a single cut (292 GJ ha-1 year-1), but it had the lowest moisture (15 %) and ashes (4.9 %) content. With a single harvest, in August, a material with lower ash and moisture content would be achieved in all three species.