SUMMARY
The study aimed to evaluate the nitrogen sources and doses application effects on the dry matter production and the sugar and alcohol gross yield of sugarcane (SP80-1816) in the cane-plant cycle in a dystrophic Red Oxisol. The experiment was conducted in the Fazenda Rio Paraiso II field, belonging to Usina Raízen, in Jataí - GO. The experimental design used was randomized blocks, arranged in a factorial scheme (2 x 4), with three replications. The treatments consisted of two nitrogen sources (urea and ammonium nitrate) and four nitrogen doses (0, 60, 120, and 180 kg ha-1). Dry matter variables were analyzed in sub-subdivided plots, as four evaluation periods were added (210, 250, 290, and 330 days after planting). The evaluation periods influenced sugarcane dry matter, and urea favored these variables to the ammonium nitrate's detriment. In contrast, the opposite occurred for stalk yield and sugar and alcohol yields, in which ammonium nitrate provided greater increments. The increase in nitrogen doses provided linear gains in practically all studied variables.