Can community level physiological profiles be used for compost maturity testing?

Community level physiological profiling utilizing Biolog plates was evaluat ed as an assay for testing the maturity of composts. Compost samples of dif ferent maturity stages were collected from a forced-aeration open windrow b iowaste composting site. Several approaches of data analysis were used. The y included single-point readings at certain well color densities, estimatio n of the area under activity curves, calculations of kinetic parameters and , finally, estimates of functional diversity. The capacity of community lev el physiological profiles to characterize compost maturity was evaluated in reference to several other physicochemical and biological (respiration, mi crobial biomass) maturity indices. Methods of optical density transformatio n and analytical procedures had little effect on the quality of information derived from principal component analysis. Except for a difference in reso lution both physicochemical parameters and community level physiological pr ofiles were suitable for identifying different stages of compost maturity. The data suggested that community level physiological profiles may be a pro mising tool for evaluation of compost maturity.