PHYSICOCHEMICAL MATURITY PARAMETERS IN THE COFFEE PULP-COW MANURE VERMICOMPOSTED MIXTURE

Abstract

Determining the degree of maturity in organic matter is an aspect of interest in the composting process. The objective of this research was measure the mineralization rate of different mixtures of coffee pulp with bovine manure and to evaluate maturity parameters related to humification, to be used in the characterization of the quality of vermicomposted mixture of coffee pulp:bovine manure. Treatments established for the pre-composting and vermicomposting processes were: 100 % coffee pulp (control), 50 % coffee pulp with 50 % bovine manure (50 CP:50 CM) and 25 % coffee pulp with 75 % bovine manure (25 CP:75 CM). CO₂ emission of the treatments, measured through the microbial respiration in the composts, was in accordance with the humification process, with a greater rate in the more humified treatments. Values of the polymerization index (PI), humic acids percentage (HAP), humification rate (HR) and humification index (HI) of the 50 CP:50 CM and 25 PC:75 CM treatments were associated with the humification parameters for maturity of compost of different origin as reported in literature. The maturity parameters sensitive to the coffee pulp with bovine manure vermicompost were PI, HAP, pH and cation exchange capacity, whose content defined the quality of the final product. Results