Soil improvers and growing media - Determination of the aerobic biological degradation rate of organic matter - Part 1: Oxygen uptake rate (OUR)

This document describes a method to determine the stability of materials (e.g. compost, digestate) used as components (ingredients) in growing media, soil improvers and organic fertilisers by measuring the oxygen uptake rate (OUR). The oxygen uptake rate is a direct parameter for the degradation rate of biodegradable organic matter that is being broken down within a specified time period. The method is not suitable for material with a content of particle sizes > 20 mm exceeding 20 % by volume. NOTE The relation between the degradation rate and the oxygen uptake rate under the same conditions is depending on the type of material, for example by the C/N ratio. So it is important for the interpretation and limit values to be set based on the type of material.