Biomass Production of the Tropical Forage Grass Pennisetum purpureum (BRS Capiaçu) Following Biofertilizer Application

Due to its high productivity, bovine confinement systems generate high volumes of waste that, when handled poorly, cause numerous environmental problems. One way to avoid such problems is anaerobic biodigestion, an efficient process used in manure treatment, resulting in biogas and biofertilizer as by-products. In this context, this study aimed to evaluate the effects of the application of a biofertilizer originated from the biodigestion of wastewater from dairy cattle activities to produce the forage grass Pennisetum purpureum (elephant grass—BRS Capiaçu). The experiments were carried out in an experimental field belonging to Embrapa—Gado de Leite, located in the municipality of Coronel Pacheco, in the state of Minas Gerais, Brazil, from March to October 2018. Different biofertilizer doses (0, 24, 48 and 72 mm layers) were applied to the elephant grass crop and mean plant height, green and dry mass, productivity, dry matter content, lignin, neutral detergent fibers and acid detergent fibers were determined. Changes in soil fertility at the end of the second cycle after the biofertilizer application were observed. When the biofertilizer was applied at the highest dose, increased forage grass productivity and CO 2 fixation were noted, although no significant effect on the assessed nutritional variables was observed. Graphical Abstract