The industrial wet-blue leather standardization process generates a by-product called leather sawdust (RR). At the beginning of this century, the Brazilian tanning industry rejected about 131 thousand tons of RR in the environment. The present study investigated the possibility of using RR as a component for growing media. Seedlings of Tagetes patula L. ‘Aurora’ were transplanted in 24 cell packs (216ml each cell) containing blends of RR and the mixture CACV (carbonized rice husks: fine vermiculite; 6:1 - v:v) in the following volumetric proportions: 0:1 (100% CACV) , 1:3, 1:1, 3:1, 0:1 (100% RR). The mixes were analyzed concerning pH value, salinity, bulk density and water retention curves. Increasing RR fraction reduced bulk density while increased the total porosity and the amount of water in micropores. The high salt content of RR (> 7g L-1 as KCl) and its natural low pH value (3,7 em H2O) can reduce plant development and therefore must be taken in to account. The results suggest the use of RR as a component for growing media in amounts up to 50% in volume.
discard of solid residues; substrate conditioner; plug production; salinity
