Pakistan Journal of Biological Sciences 2013-09-01
Efficiency of utilization of nitrogen coated with urease inhibitor in maize.
Ricardo S Okumura, Daiane de C Mariano, Paulo V C Zaccheo, Amanda N de Albuquerque, Carmo G Giebelmeier, Allan K da S Lobato, Antônio A N Franco, Neto Cândido F de Oliveira, Eduardo C M Saldanha, Heráclito E O da Conceição, Raimundo T L da Silva
This study aimed to evaluate under field conditions the efficiency in the use ofN coated with urease inhibitor in maize. The experiment was conducted in the year of 2007/2008. The experimental design was a randomized block design in a factorial 2 x 6, with five repetitions, constituted the N sources (common and coated with urease inhibitor) and levels (0, 40, 80, 120, 160 and 200 kg ha-1 of N) sidedressing nitrogen application in the growth stage V4. Based on the data obtained were determined recovery efficiencies, utilization, agronomic and physiological N applied. In all cases, the efficiency levels for maize were influenced by levels of sidedressing nitrogen application, in which increasing levels of N resulted in a decrease of the efficiencies, regardless of the source being common urea or coated with urease inhibitor.