Nitrogen is used in larger quantities than any other mineral nutrient in corn. It is also the most limiting to plant growth and development and the nutrient that most increases the production costs. The objective of this study was to evaluate the economic viability using different sources, rates and application times of nitrogen in the production of irrigated corn in Selvíria-MS, Brazil. The experiment was conducted in an experimental field belonging to UNESP - Ilha Solteira Campus, in an Acrustox. The treatments consisted of three N sources (entec®, ammonium sulfate and urea), five N rates (0, 50, 100, 150 and 200 kg ha-1) and two application times (applied at sowing or topdressing). The total operating cost (TOC), gross revenue (GR), operating profit (OP), profitability index (PI), break-even yield, and break-even price were estimated. The results showed that ammonium sulfate and urea were the N sources that allowed satisfactory economic results. Rates of 50 kg ha-1 of ammonium sulfate or urea provided higher levels of profitability. The highest levels of profitability were obtained when nitrogen application was carried out at topdressing.
Zea mays L.; no-tillage; irrigation
