Distribution of N2o Fluxes Due Soil Temperature in a Tropical Soil with Biochar Addition or Not.

Nitrous oxide (N₂O) is the third greenhouse gas in importance and a significant part of emissions occur in agricultural sector. The biochar a material rich in carbon is appointed like an option of N₂O emissions mitigation. This study aimed to evaluate the effect between soil temperature e N₂O fluxes in a tropical soil with addition of biochar or not. Was carried the incubation during 14 days using a Oxisol with pH 5.7 during de summer in South hemisphere. The treatments constituted of one with addition of 20 tons of biochar per hectare and without addition with five replicates. All plots received the equivalent of 100 kg N ha^-1 for induction of N₂O emissions and during all evaluation period every plots was kept with 70% of pores saturated with water. The vase constituted chamber where we sampled gas and followed of gas chromatography determination. Every sampling event were annotated soil temperature and were clustered in temperature ranges <20 ºC, 21-25 ºC, 26-30  ºC and >30 ºC. We observed that in the range of 26-30 ºC have occurred the most of emissions: 74% and 69% with and without biochar addition followed of range 21-25 ºC and in sampling time where the soil temperature overcame 30 ºC and less 20 ºC the fluxes were approximately zero. The distribution of fluxes between the soil with biochar addition and without were no different (p=0,37).