Chemical, physical and biological compost and vermicompost characterization: A chemometric study

The high variability of some important compost and vermicompost parameters suggests an urgent need for establishing quality assurance procedures in order to classify the available materials. The organic amendments prepared from different organic wastes (raw material), with different kind (composting or vermicomposting) and time of process, produce a final product which differs in its quality. A set of twenty-eight different compost and vermicompost were analyzed through nineteen chemical, physical and biological parameters. The chemometric evaluation was performed by the following multivariate techniques: principal component analysis (PCA) and linear discriminant analysis (LDA). The aim of this paper was to characterize and classify composted and vermicomposted materials by means of multivariate statistical analysis methods, such as PCA and typical classification techniques, LDA, by determining parameters related to their physical, chemical and biological characteristics in order to obtain useful information for both producers and consumers. Results showed a wide variation in some parameters such as total organic carbon (TOC), germination index (GI), pH, total nitrogen (TN), and water soluble carbon (WSC), which depends on the characteristics of each process. Through the use of statistical techniques, PCA, LDA, it was possible to classify all the organic amendments analyzed in the following categories: A, B-1, B-2, B-3 and C, and to give to each one the characteristics from the point of view of their quality. (c) 2007 Published by Elsevier B.V.