This study was conducted to determine the effects of supplemental irrigation and nitrogen fertilization on forage oat (Avena sativa, L.) productivity, variety UPF7. The experiment was a split-plot randomized block design with four replications. The experimental unit consisted of combinations of four irrigation depths applied when cumulative Classe A pan evaporation (ECA) approximately reached 30 mm, (I = 0%, I = 50%, I = 100% and I = 150% of ECA), and four nitrogen levels (N = O, N = 80, N = 160 e N = 240 kg.ha-1). The total maximum productivity of dry matter (6,9 t.ha-1) was obtained for the water depth of 319,2 mm and 152,4 kg.ha-1 of nitrogen. For the considered prices, the water and nitrogen levels that induced the maximum net income were 310 mm and 120 kg.ha-1, respectively, reaching a maximum net return of R$ 897.ha-1.
suplemental irrigation; nitrogen fertilization; optimal levels; net return
