Ammonia volatilization from surface application of organic residues and urea on marandu palisadegrass

Abstract

The objective of this study was to measure ammonia volatilization from surface application of pig slurry,poultry litter, urea and no fertilization. An experiment was conducted in a randomized block design, in plots repeated overtime, with four treatments and four replications. The fertilizers tested were: mineral fertilizer (70 kg ha-1 N, 100 kg ha-1 P2O5and 30 kg ha-1 of K2O, as urea, triple superphosphate and potassium chloride, respectively), pig slurry (200 m3 ha-1 applied inNovember 2008 and 200 m3 ha-1 applied in April 2009) and poultry litter (10 t ha-1 applied in November 2008 and 10 t ha-1 appliedin April 2009). Five evaluations were performed with 24-hour intervals. Foams were used with glycerin and sulfuric acid,internally fixed in PET bottles for collecting ammonia. After collected, the samples were sent to the laboratory to determinevolatilized ammonia levels by the semi-micro Kjedahl distillation method. Fertilization with chicken litter had lower ammoniavolatilization in relation to urea and pig slurry. Most of the ammonia volatilization from pig slurry occurred within 48 hoursafter application, totaling losses of 630 g kg-1 of a total of 8.25 kg ha-1 of volatilized ammonia. The biggest loss by ammoniavolatilization was from fertilization with urea, totaling approximately 80 g kg-1 of N applied.© 2013 Sociedade Brasileira de Zootecnia.