According to Smirnoff and Stewart (1985), the Rosaceae species are experts in the use of nitrogen as nitrate form. There was a predominance of this form of nitrogen in the effluent from the sand filters; however, no significant difference was found with the use of the anaerobic effluent, which contains it in the organic and ammoniacal forms. In turn, Feigin et al. (1986) suggest that the optimal ratio between NH 4 + : NO 3 − is equal to 25:75 % for rosebush cultivation, there is a higher productivity when compared to fertilization with 100 % nitrate. In this study, the anaerobic and nitrified effluents showed the proportion of NH 4 + : NO 3 − equal to 98:2 % and 14:86 % respectively, with no statistically significant difference between tests in which there was a predominance of each of these compounds (T2 to T5). Cabrera (2001) while employing different proportions of NH 4 + : NO 3 − in the cultivation of potted roses also found no difference in productivity after 13 months of production.