Chemical Composition and Energy Yield of Elephant-Grass Biomass as Function of Five Different Production Ages

Abstract

Elephant grass has high biomass production, with qualities suitable for conversion into bioenergy, but has long been used exclusively for animal feed and only in recent years has it become an energetic alternative. Therefore, it is necessary to select genotypes with potential for energy production. This study evaluated the effect of five harvest times (8, 12, 16, 20, and 24 weeks) on the yield and chemical composition related to biomass quality through combined polynomial regression analyses of the following elephant grass genotypes: Cubano Pinda, Mercker 86-México, Pusa Napier n°1, Mole de Volta Grande, P-241-Piracicaba, and King Grass. A completely randomized design with three replicates, in a split-plot arrangement, was adopted, including two factors (plots = genotypes, subplots = harvest times). The evaluated variables were whole-plant dry matter yield, in t ha -1 (DMY), percentage of neutral detergent fiber (%NDF), and percentage of acid detergent fiber (%ADF). The elephant-grass genotypes Cubano de Pinda, Mercker 86-México, and P-241-Piracicaba showed a linear first-degree effect as a function of the harvest intervals, indicating that they did not reach their maximum production potential. Genotypes Pusa Napier n°1, Mole de Volta Grande, and King Grass, in turn, had a linear second-degree effect. For the NDF variable, all genotypes showed a significant linear second-degree effect as a function of the harvest intervals, except P-241-Piracicaba, for which no regression was observed. For this genotype, there was a significant linear first-degree effect on the %ADF variable.

Growth curve in elephant grass genotypes based on morpho-agronomic traits for energy production

“…The maximum yield point for this genotype was achieved at 10.25-mo, with an estimated maximum DMY of 26.44 t ha -1 (Figure 3). The increasing tendency in DMY with the increase in the cutting age, evidenced in this experiment, is in line with the results found by Freitas et al (2018) with elephant grass. It could also be noticed that cutting plants at more advanced stages of growth provides higher forage yields because of the longer period for DM accumulation (Vidal et al, 2017).…”

Bromatological Composition of Elephant Grass Genotypes for Bioenergy Production

“…For the production of biomass for energy use, the higher NDF content, better is the biomass quality. [26,27] In the first year of cultivation, comparing both seasons (dry and rainy), most of the genotypes had the same hemicellulose content (P > .05), except for the genotype CNPGL 93-41-1 that obtained lower hemicellulose content in the dry period (21.33%). When evaluating the behavior of the genotypes within the seasons, there was no difference in hemicellulose content and the average was 24.81% (Table 2).…”

The genotype does not influence the establishment of elephantgrass (Pennisetum purpureum Schum.)

“…Elephantgrass (Pennisetum purpureum Schumach.) is a warm-season grass species known for its elevated potential for biomass accumulation and forage productivity (Freitas et al, 2017). It has been used in animal feeding via grazing (Crestani, Ribeiro Filho, Miguel, Almeida,& Santos, 2013), cut-and-carry fresh (Pereira, Lédo,& Machado, 2017), or conserved (e.g.…”