Doses and time of application of nitrogen in upland rice

Abstract

The aim of this work was to evaluate the behavior of upland rice cultivars under different doses and application time of nitrogen fertilization in Northern Mato Grosso State. The experiment was carried out during the crop seasons 2007/2008 and 2008/2009, in an experimental site at Alta Floresta, MT, Brazil. The experimental design used was randomized blocks in a 2x3x4 factorial scheme, with 24 treatments and four replications. The treatments evaluated were two cultivars (BRSMG Curinga and BRS Maravilha), three nitrogen applications time (100% at sowing, 50% at sowing + 50% at pre-flowering, and 100% at pre-flowering) and four nitrogen doses (0, 30, 60, and 90 kg ha-1), using urea as nitrogen source. The plant parameters evaluated were: heights, internodes length, culm diameter, tillers and panicle number and grain yield. The cultivar Maravilha was more exigent in nitrogen than ‘Curinga’. In the crop seasons 2007/2008 the treatment involving split application of nitrogen fertilizer by 50% at sowing and 50% pre-flowering was more efficient. ‘Curinga’ presented higher grain yield at 63.41 kg ha-1 of N, and ‘Maravilha’ increased grain yield until the dose of 90 kg ha-1 of N explained by linear response.

Keywords

• Oryza sativa
• nitrogen fertilization
• growth and yield components