Respiration Rate – Reheating Potential: A Comparison of Measures of Compost Stability

Abstract

In this study, respiration rate was found to be a useful tool for assessing the relative stability of compostable materials. Internal windrow temperature and/or reheating potential were compared to respiration rate, and therefore, to the degree of compost stability. Parameters that evaluate biological activity, such as respiration rate and reheating potential, exhibited an ability to indicate compost stability. There are no federal regulations and only a limited number of state regulations regarding compost stability or end use. Minnesota, New York, Florida and a few other states have developed classifications for maturity or end use. These regulations generally define mature or stable compost as having achieved 60 percent decomposition or having been in active decomposition for at least 180 days. Reheating potential or declining windrow temperatures have been used as qualitative measures of maturity.