Production and nutritive value of ryegrass (cv. Barjumbo) under nitrogen fertilization

Abstract

Alternative production of forages in periods of scarcity, especially during the winter, is expressively important for grazing of beef and dairy cattle in Brazil. The current work aimed to evaluate the influence of nitrogen fertilization on the production and nutritional value of ryegrass forage (cv. Barjumbo). The experiment was carried out on the winter seasons of 2009 and 2010, at the experimental area of UTFPR, Dois Vizinhos-PR, Brazil. The design consisted of randomized blocks with four N rates (0; 40; 80 and 120 kg ha-1) and three replicates. Each plot measured 5×5 m, with 20 cm row spacing and 2.5 cm between plants, totaling 20 kg ha-1 of viable seeds. It was determined the dry matter production, crude protein level, total accumulation of crude protein and neutral detergent fiber, during the whole growth cycle of ryegrass in two crop seasons. Nitrogen fertilization promotes a significant and linear increase in dry matter yield and in accumulation of crude protein, with the best results with the highest rate evaluated (120 kg N ha-1). Nitrogen levels are not capable to promote significant effects in forage neutral detergent fiber content.