USING PHOSPHOGYPSUM AND VINASSE FOR ENRICHMENT OF RUMINANT CONTENT COMPOSTING IN THE TROPICS
Organic wastes from the meat industry are a particular problem because the effluents are mixed and have high organic matter content. There are other by-products such as phosphogypsum (PG) and vinasse (V) from the phosphate fertilizer and rum industries respectively, which are problematic. Instead of looking at these by-products as pollutants, they might be seen as inputs for a wide range of agricultural uses from compost making to animal feeding. The objectives of this study were to measure some physical and chemical substrate properties during composting of slaughterhouse waste (mainly ruminant content) from a meat preparation in Barquisimeto, Lara state, Venezuela with added PG and V, and to evaluate the potential of these amendments for improving the final product. The ruminant content (RC) was treated with the amendments in the ratios of 20 and 40% each to RC on a dry matter basis. Composting was done for 45 days and parameters monitored over this period included temperature, pH, electrical conductivity (EC), and at the end, the moisture content (mc), water retention (wr), bulk density (bd), air-filled (ap) and total porosity (tp), nitrogen content (N) and C/N ratio were measured. Changes in temperature, pH and EC during composting were observed consistently, however, there were not any significant differences between the base compost (RC only) and amended composts. The highest air-filled and total porosity values were observed for 20% V. The treatment with 40% PG had the highest N content and the lowest C/N ratio. The final product quality of the RC with PG and V was positive in the radish bioassay germination, indicating that its use as a growing medium would not cause toxicity to plants and horticultural environment.
Ramirez-Guerrero, H.O., Molina-Aguilera , G. and Moyeja-Guerrero, J.C. (2012). USING PHOSPHOGYPSUM AND VINASSE FOR ENRICHMENT OF RUMINANT CONTENT COMPOSTING IN THE TROPICS. Acta Hortic. 933, 293-296
industrial wastes, organic substrates, fertilizer, slaughterhouse wastes