Production and Bromatological Characteristics of Elephant Grass—Cenchrus purpureus (Schumach.) Morrone—Planted Under Application of Industrial Biosolid and Chemical Fertilization

Abstract

Biosolid, i.e., dehydrated sludge from effluent treatment stations, has been progressively used as an agricultural fertilizer due to its high organic matter and nutrient contents. Elephant grass (Cenchrus purpureus (Schumach.) Morrone) presents easy adaptation and high yields, being used for animal feeding and for energy purposes. The objective of this work was to analyze the production and bromatological parameters of elephant grass with four different doses of biosolid, one of chemical fertilizer and a control plot, with two replicates each. A field experiment was carried out using a randomized block design with three blocks, totaling 18 plots, which received biosolid fertilization at 1×, 2×, 4×, and 8× the levels recommended by the Brazilian National Environment Council, along with conventional chemical fertilization and no fertilization, all under similar drip irrigation. Tukey’s test indicated a significant difference at p < 0.01 for total production in the first cut and acid detergent fiber in the second cut. At p < 0.05, significant differences were detected for total nitrogen and total protein in the first cut. The elephant grass yield under “1× biosolid” was similar to that reached with chemical fertilization. Physical and bromatological characteristics indicated potential use as animal feed and energy source. For doses higher than specified by Brazilian standards (2×, 4×, and 8×), further studies are required to verify possible contamination from heavy metals, pathogenic microorganisms, and n.