Among the practices and techniques employed for obtaining increased corn yield, the choice of plant arrangement and time of nitrogen topdressing are, among the most important, associated with the choice of the hybrid and cropping system. The objective of this trial was to study the influence of four nitrogen application timing, associated with three sowing rates and two row spacings, under no-tillage system, using two corn hybrids in southeastern Tocantins State. On the site, two experiments in no-tillage system were established, the first one being set up with the spacing of 0.45 m and the second spacing of 0.90 m. In each experiment, two corn hybrids (P 30K75 and TORK), three sowing rates (55 thousand, 70 thousand and 85 thousand plants ha-1) and four nitrogen application timing: 40 kg ha-1 of N applied at sowing time without nitrogen topdressing; 40 kg ha-1 of N at sowing + 120 kg ha-1 of N topdressed just after sowing; 40 kg ha-1 of N at sowing + 60 kg ha-1 of N topdressed at the stage of 4 to 5 leaves + 60 kg ha-1 of N topdressed at the stage of 7 to 8 leaves, 40 kg ha-1 of N at sowing + 120 kg ha-1 of N topdressed at the stage of 6 to 7 leaves. Fractioning nitrogen application increased corn grain yield. As plant density increased, plant height and grain yield increased. Plant spacing of 0.45 m promoted higher grain yield regardless plant density and hybrid used. The P30K75 hybrid obtained higher grain yield than TORK hybrid.
Zea mays; management of nitrogen fertilization; plant arrangement; tillage system
