Carbon mineralization and distribution of nutrients within different particle-size fractions of commercially produced olive mill pomace

► Nutrient and carbon mineralization of composted olive mill pomace were analyzed. ► Quality and particle distribution differed according to the material co-composted. ► Higher content of nutrients and lower carbon contents were found in finer particles. ► Larger particles had higher contents of organic matter and phytotoxic properties. ► Particle size separation facilitates better management of this compost.