. Nitrogen fertilization as top dressing for the corn following black oats under a no-tillage system

• Autor(a) principal: Oliveira, João Manoel Santos de
• Data de Publicação: 2008
• Outros Autores: Caires, Eduardo Fávero
• Tipo de documento: Artigo
• Idioma: por
• Título da fonte: Acta Scientiarum. Agronomy (Online)
• Texto Completo: http://www.periodicos.uem.br/ojs/index.php/ActaSciAgron/article/view/1926
• topic: Zea mays L.; uréia; sulfato de amônio; nitrogênio; 5.00.00.00-4 Ciências Agrárias

A field experiment was carried out on a red dystrophic loam oxisol from Tibagi, Paraná State, Brazil, to assessing whether surface-applied urea affects corn development and yield as a result of N-NH3 losses by volatilization, and whether the partial or full replacement of urea by ammonium sulfate increases the effectiveness of nitrogen fertilization as sidedressing, without incorporation. A randomized complete block design was used, with three replications, in a split-plot experiment. The plots received four rates of N applied as top dressing: 30, 60, 90 and 120kg ha-1. The subplots were constituted by four application forms: surface-applied urea, incorporated urea, surface-applied ammonium sulfate and surface-applied urea + ammonium sulfate. The N rates led to a linear increase in corn yield, number of grains per ear, ear weight per plant, grain weight per ear, and weight of 1000 grains. Urea, surface-applied or incorporated, and surface-applied ammonium sulfate performed similarly in nutrition and corn grain yield.