Qualidade do composto orgânico em função da cobertura do pátio de compostagem e da frequência de revolvimentos

Abstract

The Western Region of Paraná has a large number of agro-industrial cooperatives, standing out in the production and export of chicken meat. However, this activity has a high generation of residues, both in the pre-fattening phase and in the meat slaughtering and processing phases. Currently, this waste has been destined to composting plants, whose main challenge is to optimize the process, aiming at reducing composting time and increasing the quality of the final compost. Thus, this work had the objective of evaluating the influence of the factors composting patio cover and frequency of turning in the quality of the final organic compound. For this, 6 composting piles (treatments) were made, with each lawn being the combination of two factors: composting patio cover and frequency of turning. The piles were made using residues from the productive chain of the broiler chicken and all had the same constitution. During the composting process, temperature and mass and volume reduction were observed. To evaluate the quality of the final product macro and micronutrient analyses were carried out, as well as phytotoxicity test, pH, electrical conductivity, cation exchange capacity, and water soluble organic matter analyses were performed. The use of the composts as substrate for cultivating vegetable seedlings was also tested. The temperature of the piles reached the thermophilic phase on the first day of composting, reaching temperatures up to 69 °C. The greatest reduction of mass and volume occurred in the pile that was conducted in open patio, reaching 56% of mass reduction and 72% of reduction of volume. The larger reduction of macronutrients was also observed with the increase of the frequency of changes and the exposure of the pile to the climatic effects. It was concluded that the cover factor of the composting patio was the one that most influenced the quality of the organic compost, significantly reducing the macro and micronutrient contents. The factor of frequency of turning contributed for a larger reduction of mass and volume in the lawns and with the greater reduction of nitrogen. At the end of the process, the composts were considered stabilized and able to be marketed, according to MAPA’s IN 25.