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 over time, with four treatments and
four replications. The fertilizers tested were: mineral fertilizer (70 kg ha-1 N,
100 kg ha-1 P2O5 and 30 kg ha-1 of K2O, as urea, triple superphosphate and potassium
chloride, respectively), pig slurry (200 m³ ha-1 applied in November 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 applied in 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 determine volatilized ammonia levels by the semi-micro Kjedahl distillation method.
Fertilization with chicken litter had lower ammonia volatilization in relation to
urea and pig slurry. Most of the ammonia volatilization from pig slurry occurred within
48 hours after application, totaling losses of 630 g kg-1 of a total of 8.25 kg ha-1
of volatilized ammonia. The biggest loss by ammonia volatilization was from fertilization
with urea, totaling approximately 80 g kg-1 of N applied.