The objective of this work was to determine the most adequate nitrogen (N) dose and the mode of its application for the upland rice grown after pasture or soybean, under no-tillage. The experiments were carried out during the 1999/2000 growing season, in Santo Antônio de Goiás, GO, after Brachiaria decumbens pasture, and in Campo Verde, MT, after soybean. A completely randomized block design was used, in a 5 x 3 factorial scheme. The treatments consisted of five doses of N (12 or 7, 40, 80, 120, and 160 kg ha-1) combined with three modes of application: total at sowing, half at sowing and half top dressing, and two third at sowing and one third top dressing. N dose of 12 kg ha-1 was applied in the first experiment and N dose of 7 kg ha-1 in the second one. Rice showed higher response to N fertilization after pasture in comparison to soybean. Rice grain yield response to N after pasture depended on mode of application, 100 kg ha-1 being the economic dose for total N application at sowing. Rice grain yield, following soybean was not affected by mode of application, under this condition, the economic dose of N was 68 kg ha-1.
Oryza sativa; C:N ratio; N application form
