Regarding the manure management systems used by the Brazilian
swine producers, the use of biodigestor seems to be the most
favorable alternative, especially if the captured biogas is used for
energy purposes. An additional advantage of the biodigestor scenarios
is the agronomic value of the manure due to the higher
mineralized N content. According to some studies (Amon et al.,
2006; Chantigny et al., 2007) the reduction of the dry matter content
increases the infiltration rate of the manure into the soil and
thereby reduces the NH3 emissions after manure application.
However, in our estimation the high content of total ammonia nitrogen
resulted in the high potential for NH3 emissions generating a
greater terrestrial acidification for Sce.Flare, Sce.CHP and Sce.Comp
(see Table 4), which highlights the importance of the need to better
understand the N-related emissions.