This research aimed to study the possibility of recovery of waste from the canning industry of palm heart as substrates for vegetables. The fiber of Australian king palm (Archontophoenix alexandrae) was used in natura (FN), collected immediately after the heart extraction, and after the acid hydrolysis process (FH), in the proportions 1:1:1 (v:v:v) leaf, "cartridge" (sheaths) and stipes. Materials in pure form (100% FN and 100% FH) and their mixtures with in natura brown peat, in volume proportions (80:20, 60:40, 40:60, 20:80 and 0:100%), were submitted to physical (moist and dry bulk density, total porosity, air space and available water), and chemical analyses (pH and electric conductivity), in completely randomized design with three repetlications. All results were submitted to variance analysis and, when statistically significant, to regression analysis. Both pure FN and FH presented low dry density, high values for total porosity and air space and low water retention. All mixtures with peat showed density reduction. The addition of FN to peat increased total porosity, air space, and reduced available water. FH added to peat reduced the total porosity and available water, and increased the air space. FN and FH also increased the peat pH value. However, the addition of FN increased the electric conductivity, while the addition of FH decreased it significantly. Considering the availability of palm residues and its excellent characteristics after the acid hydrolysis, this may constitute a basic material for the formulation of substrates.
Archontophoenix alexandrae; Australian king palm; vegetables; peat; acid hydrolysis; physical characteristics; chemical characteristics
