Ammonia volatilization in corn crop as a result of the application of different nitrogenous fertilizers

The experiment was carried out in a greenhouse with samples of Eutroferric Red Latosol. On each of these samples, an amount of 800 mg/kg of N was superficially added in the soil. The experiment consisted of five industrial sources of nitrogen, urea (45% of N), urea plus (45% of N), ammonium sulfate (20% of N and 24% of S), Yarabela® (27% of N) where we assessed the volatilization 1, 2, 5, 7, 10, 14, 18 days after the application of the doses. Two methodologies were tested, semi-open static system and the method developed by Miyazawa (2007). After the volatilization assessment of each source, we cultivated a corn plant on each vase for 30 days to evaluate the residual effect of the fertilizer in the crop development through the plant height, stem diameter, dry biomass production of the aerial part and content of N in the vegetal tissue of the aerial part. The urea and the urea plus showed higher volatilization in both ammonium collecting systems and the ammonium sulfate and Yarabela® had the lower volatilization rate. The spectrophotometer detected low levels of nitrogen in comparison to the distillation method. Key words: Nitrogen, volatization, urea, residual effects.