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Resumo – A atividade suinícola tem grande importância no Brasil e, por isso, busca-se utilização adequada do dejeto líquido de suíno (DLS) em áreas agrícolas. O objetivo deste trabalho foi avaliar os efeitos da aplicação de DLS e ureia, tratados ou não com inibidor de nitrificação (DCD), e o modo de distribuição dos fertilizantes na presença e ausência de resíduos culturais sobre as emissões de CO2 em ambiente controlado. O solo utilizado para a condução do trabalho foi um Cambissolo Húmico, para avaliar as emissões diárias e acumuladas de CO2. As emissões diárias de CO2 aumentaram com a utilização de DLS. Não houve efeito relacionado ao modo de aplicação dos fertilizantes. A utilização de palhada aumentou as emissões de CO2. As emissões acumuladas de CO2 foram maiores nos tratamentos com a utilização de palha combinada ao uso de DLS. Abstract – Swine production is fundamental in Brazil and it seeks suitable use for swine slurry (SS) in agricultural areas. The objective of this study was to evaluate the effects of SS and urea application, treated or not with nitrification inhibitor (DCD) and the way of fertilizer distribution, associated or not with crop residues, on CO2 emissions in a controlled environment. The soil used in this study was a Humic Dystrudept soil and daily and accumulated CO2 emissions were measured. Daily CO2 emissions increased with SS use. There was no difference considering the way the fertilizers were applied. The use of straw increased CO2 emissions. Accumulated CO2 emissions were higher under use of straw associated with SS.

ABSTRACT The injection of nitrogen sources into the soil and use of nitrification inhibitor can improve the efficiency of applied nitrogen and minimize losses to the environment. The objective of this study was to evaluate the effect of swine slurry (SS) and urea in two modes of application in the soil (injected and surface), and the use of nitrification inhibitor on NH3 volatilization in a controlled environment, upon varying soil texture and soil pH conditions. The experiment was conducted under controlled conditions, or a Rhodic Kandiudox and Typic Hapludult soil in a completely randomized design in a 4 x 2 x 2 x 2 factorial design with three replications. The study evaluated four fertilizers (urea, SS, SS +nitrification inhibitor (dicyandiamide-DCD) and control), two pH conditions (natural and limed) and two forms of fertilizer application (injected and surface), and two soils. The SS rate used was 21 m3 ha-1, and the rate of the inhibitor was 10 kg ha-1. The evaluations consisted in daily accumulated ammonia volatilization up to 14 days, and the percentage of soil nitrogen loss. The injection of fertilizers reduced emissions of ammonia in both soils and, limed soil had higher N losses by volatilization. The inhibitor did not increase the emission of ammonia in both soils.