Forms of flower production impacting on soil quality which is determined by different factors, among them the organic matter content. The objective of this study was to determine the mineralization of the organic matter through the release of C-CO2 in three systems with differential management of the soil in rose production: conventional (SPC), organic (SPO) and conventional-organic (SPCO). Throughout five months it was quantified monthly: organic N, nitrates and organic matter. Aerobic soil incubations were performed between (13 - 15 d) and the accumulated mineralized organic carbon was estimated. The values decreased during the study of 983 mg C-CO2 kg-1 to 167 mg C-CO2 kg-1 and was statistically higher (p < 0.5) in SPO and SPCO with respect to SPC, attributed to the SPC system had handled 90% with application of synthetic agrochemicals, which negatively impact on microbial activity and therefore in a low mineralization of organic matter.