Dear NOSB members and those interested in compost teas: I have been informed in the last few days that the process of making amplified aerobic microbial cultures starting with high quality compost, aerated water and nutrients to create a high bacteria and fungal count product useful in horticultural and agriculture has come under doubt, and has been slated to be placed under 120 day restrictions similar to those for raw manure.
The reason proposed for this is supposedly that, under certain conditions, a nutrient solution will support growth of 'enteric pathogenic bacterial organisms' such as E.coli and Salmonella spp. I would very much like to see the specific details of the experiments which underly the judgment reached by the National Organic Standards Board Compost Task Force when it issued the following: "2. Compost and Vermicompost teas The use of a liquid compost extract, or "compost tea", raises special issues. The preparation and use of compost tea and compost extract has been increasing in the U.S. during recent years. Organic producers especially are interested in compost teas and extracts because the preparations reportedly provide some degree of control of foliar and root pathogenic organisms. Various methods and practices have developed for production of the teas or extracts since the practice originated some years ago in Europe. However, recent research at the USDA Agricultural Research Service's labs in Beltsville, MD and Corvallis, OR shows that certain approaches to compost tea or extract preparation are conducive to growth of enteric bacterial pathogenic organisms, such as enterotoxigenic E. coli and Salmonella. The practices and procedures that lead to pathogen growth in the prepared teas and extracts involve the addition of supplemental nutrients such as sugars, molasses or other readily available (soluble) carbon sources during batch production. The researchers did not observed growth of enteric pathogenic organisms when compost tea or extract was prepared only with water and high quality compost. By high quality compost, they mean compost that has met criteria for destroying pathogenic organisms, i.e., 131ºF for 3 days, or compost that has less than 3 MPN salmonella per 4 grams compost (dry weight) and less than 1000 MPN fecal coliforms. The critical determinant regarding pathogen growth in compost teas and extracts is the addition of the carbon sources like sugars, molasses, or yeast or malt extracts during the "brewing" phase. Recommendation: Compost teas if used in contact with crops less than 120 days before harvest must be made from high quality compost described above and not prepared with addition of supplemental nutrients such as sugars, molasses or other readily available (soluble) carbon sources." http://www.ams.usda.gov/nop/CompostCMTTskFrceRec.pdf This matter was brought to my attention in the pages of Dr. Elaine Ingham's internet newsletter: http://www.soilfoodweb.com/ezinearchives/may2002.html I have been using compost tea for the last two years, using the aerobic/nutrient added method. We are making extensive use of it in an apple orchard, and I use it in landscaping, gardening and lawn care. I have accepted as a working basis the judgment of Dr Ingham that good compost, good aeration and appropriate amounts of nutrients would yield a good quality tea that would offer benefits to plant growth and not pose a significant risk to human health. My results so far have given me no reason to doubt Dr. Ingham's judgment. So, I find this recommendation of the NOSB's Compost Task Force needs closer examination to see if in fact the experiments were properly done and indicate a real problem, or if, as Dr Ingham asserts is likely, they were poorly done and, used as the foundation for judgment, will result in the unnecessary exclusion of a valuable biological technology for organic and other growers. So I would like to have a full, detailed account of the conditions under which these experiments have been carried out. It strikes me as very peculiar that Dr Ingham has not run into pathogen problems in the course of working with hundreds of aerobic, nutrient added brewed compost teas, while other researchers claim to find them. Something in the parameters of the processes must be substantially different for such divergent results to occur. I feel it is crucial for the credibility of the organic movement to make these kinds of scientific decisions as transparent and open to scrutiny as possible. Replication of both positive and negative results and the use of peer-reviewed publications would be very helpful in making clearer what does, and what does not work in the use of microbial cultures, and thus what should be allowed, restricted or excluded under an appropriate regulation regime. All comments and further information are welcome, Frank L. Teuton III, BGS, JD [EMAIL PROTECTED]
