Lien Chow1, Charles Everett2, John Monteith1, Ron Pond2, Herb Rees1, Clinton Ronalds1, Roger Theriault3 and Pat Toner2
Partner: Agri-conservation Club
Abstract: In 2001, a multi-year field trial was conducted in Bass River to evaluate the effects of a down slope 30 meter grass buffer in filtering E. coli bacteria horizontally and vertically from surface applied liquid dairy manure. Three fields of equal size and topography were surveyed by GPS to within 0.5-meter accuracy. Topographic information allowed for the establishment of eight surface and sub-surface water collection devices in each field, four at the beginning and four at the end of a 30 meter buffer. One field-designated control received no manure. The remaining fields each received 5,000 gal/ac and 6,000 gal/ac in July and October respectively. One field receiving manure was aerated prior to manure application. Within 24 hours of a rain event, samples were collected and tested for E coli. Statistical analysis using t-tests (P = 0.10) were conducted comparing average seasonal E. coli levels between fields and within field buffers. Only the aerated field exhibited significant increase in average seasonal E. coli when entering the down slope buffer area. As well, a reduction in average seasonal E. coli levels was almost significant across the buffer of the aerated field.
1Agriculture and Agri-Food Canada, Fredericton, NB
2 NB Department of Agriculture, Fisheries and Aquaculture, Agriculture Development Branch, P.O. Box 6000, Fredericton, NB, E3B 5H1
3 New Brunswick Department of Environment and Local Government / P.O. Box Fredericton, NB E3B 5H1