Resumen

DELGADO, Rodolfo; VELASQUEZ, Lorenzo  y  CABRERA DE BISBAL, Evelyn. Epoca de aplicación y tipo de fertilizante nitrogenado sobre el patrón de acumulación de materia seca y nitrógeno del maíz en un Ultisol y un Mollisol de Venezuela¹ . Agronomía Trop. [online]. 2004, vol.54, n.4, pp.461-480. ISSN 0002-192X.

Types of N sources, and time of N-fertilizer application could affect N use and yield production of maize, Zea mays L. In this experiment, maize response to application of 120 kg N ha-1 applied as urea, ammonium nitrate (AN), and an ammonium source (10-26-26), and time of application of the sidedress was evaluated in an Ultisol and in a Mollisol of Venezuela. Normally there were more dry matter production, and N uptake under NA. In the Mollisol, early application of the N dose (the whole N at sowing or side dressing at 15 days) allowed more N uptake by the crop than late application of the element (sidedressing at 25 and 35 days).

Palabras clave : N fertilizers; Zea mays L; N sources; N split; dry matter; N uptake.