Nitrogen is the most accumulated and costly nutrient in wheat production. The objective this study was to evaluate the economic viability of using different sources, doses and application times of nitrogen in the production of two irrigated wheat cultivars in Selvíria-MS. The experiment was conducted at an experimental area belonging to UNESP - Ilha Solteira Campus, in an Acrustox. The economic analysis was based on the production costs of 2007 and 2008 and the increase in production related to different management of nitrogen fertilization corresponding to each treatment of a 5x3x2x2 factorial. The treatments consisted of five N doses (0, 50, 100, 150 and 200 kg ha-1), three N sources (Entec®, ammonium sulfate and urea), two application times (applied at sowing, sidedressing or topdressing), and two wheat cultivars (E 21 and IAC 370), with 4 repetitions. The results showed that increase in value of production for the farmer was higher in June 2008. The application of 50 kg ha-1 N led to economic advantage independent of source and time of application. Topdress of urea, independent of the N dose, provided good profit margins for the cultivars E 21 and IAC 370 in 2008. The highest profit margin for the two cultivars was obtained with ammonium sulfate at todressing, applying 50 kg ha-1 N, either in 2007 or 2008.
N doses; N sources and time of nitrogen application; profit margin; Triticum aestivum L.
