Submitted to: Biocycle
Publication Type: Trade Journal
Publication Acceptance Date: 6/1/2005
Publication Date: 7/1/2005
Citation: Clark, S., Cavigelli, M.A. 2005. College composting program matures. Biocycle. July: 35-38. Interpretive Summary:
Technical Abstract: In 1998 Berea College embarked upon a pilot program to compost food residuals as a means of generating an organic soil amendment and demonstrating the feasibility of responsible waste management to students and community members. The program has since become a fundamental part of the College’s garden and greenhouse program, the horticultural component of the College’s 500-acre educational farm. The modifications in management made over the years have not only improved the utility and efficiency of the composting program, but provided educational and research opportunities as well. Research has included comparing the performance of Berea food residuals compost with local and commercial products in various mixes as horticultural potting media in organic production systems. Lettuce and tatsoi were used as test crops. Although the food residuals compost and a regionally-produced horse bedding based compost had relatively similar total N contents, C:N ratios, and bulk densities, they performed quite differently as potting media. Only the treatments with 100% food-residuals compost and the commercial potting medium with synthetic fertilizer had acceptable plant germination and growth during the study. Crop production in these two media was statistically similar. Differences in plant growth among the media were apparently due to salinity and mineral N availability. Net N mineralization, measured in laboratory incubations, was high in the food-residuals compost but negative in the horse-bedding compost, perhaps due to high salinity. The research shows that the food-residuals compost, used at 100%, performs as well as the commercial peat-based medium for plant production, but is somewhat more expensive. However, the slightly higher cost is acceptable for organic producers given the price premium received by organic producers.