Modifications to Existing Codes and Ordinances: Bioassay of Microbial Diversity in Compost

摘要

Application and use of compost in urban and agricultural landscapes has become a common practice for maintaining healthy soils and restoring ecological balance. While testing protocols have improved since 2006, many materials labeled as "compost" are only anaerobic decomposing organic matter due to both processing and packaging. This paper presents research indicating that aerobic compost, with confirmed active and diverse microbial populations, provides the environment necessary for proper nutrient cycling performed by the soil foodweb. This paper will propose a revision to the quality testing protocols specified by the U.S. Composting Council ("USCC"), the American Society for Testing and Materials ("ASTM") and the US EPA Report SW-846 to include biological assays to reflect the diversity of microbial populations in compost using expanded methods to include direct microscopy, updated molecular techniques, phospholipid fatty acid analysis, and plate counts using numerous agar food sources. Currently, a bioassay of compost analyzes only possible existence of pathogens, stability of compost by measuring oxygen consumption, or seed emergence and seedling vigor relative to positive controls. This paper proposes that compost, meeting this expanded testing requirement, will ensure nutrient and water retention in soils to maintain and improve health of stormwater runoff and related environmental impacts.