Evaluation of food processing residual compost for horticultural use

Date of Completion

January 2003


Agriculture, Agronomy|Agriculture, Food Science and Technology|Agriculture, Soil Science




Experiments were conducted in 1998 and 1999 to evaluate a regionally-produced compost derived from food processing residuals (FPR). The objectives of these experiments were to (1) examine several compost evaluation methods during the curing process of FPR compost and (2) evaluate FPR compost as a nutrient source for organic salad green crop production. ^ Eight compost evaluation methods were evaluated during a three-month curing process of FPR compost to provide characterization of the cured FPR compost prior to field application. The FPR composts were applied at five rates in 1998 and four rates in 1999, on two certified organic farms in Connecticut. The nutrient sources evaluated were cured FPR compost, uncured FPR compost, and a commercial organic fertilizer. The evaluative variables were soil pH, soil organic matter, salad crop yields, and extractable soil nutrients. All nutrient sources had minor influence on soil pH. Soil organic matter was significantly increased with increased application rate of FPR compost, whereas organic fertilizer had limited effects. Variability in compost feedstocks led to inconsistent results for FPR compost in the production of salad greens. This project showed that FPR compost was a reliable nutrient source that resulted in crop yield increases in Year 1, but in Year 2, crop and soil nutrient results varied, possibly because of N immobilization. Benefits of curing the FPR compost were marginal for field use. Commercial organic fertilizer was a better nutrient management strategy for salad green production as compared to FPR compost because consistent crop yields were obtained with organic fertilizer treatment and greater soil N availability was observed with the organic fertilizer. Both FPR composts and organic fertilizer increased soil P, which may contribute to the potential of excessive long-term soil P accumulation. ^