Ecotoxicology of Pig Slaughterhouse Waste Using Lactuca sativa L., Raphanus sativus L., and Oryza sativa L.
Pork is the most consumed animal protein around the world. The production levels are significant, which results in the generation of large amounts of slaughter waste. Such waste is often disposed of improperly in agricultural areas, causing environmental imbalance by the contamination of soil and water sources with metals and pathogenic organisms. This study evaluates the phytotoxic effects of pig slaughterhouse waste in natura and after stabilization processes on lettuce (Lactuca sativa Linnaeus, 1753), radish (Raphanus sativus Linnaeus, 1753), and rice (Oryza sativa Linnaeus, 1753), in addition to shoot nutrient contents. To do this, the waste was evaluated through phytotoxicity tests on lettuce, radish, and rice plants in natura (PSWin) as well as after aerated composting (PSWa), natural composting (PSWn), and vermicomposting (PSWv). The evaluations were done through germination, root length, plant development, and shoot nutrient analysis. We found that PSWin and PSWa negatively affected germination, root length, and plant development. Shoot nutrient contents varied greatly among treatments, some of which were above, below, or within the recommended limits. Based on these results, we infer that pig slaughterhouse waste in natura and after aerated composting is phototoxic to lettuce, radish, and rice plants. Phosphorus and sulfur exhibited contents above those recommended in all the treatments for lettuce, radish, and rice. On the other hand, potassium and calcium contents were below the recommended thresholds.