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Beneficial Uses of Compost in Florida Vegetable Crops - Page 2
Composts made from the following organic waste materials are available to use in Florida vegetation crop production:
Municipal solid waste includes paper, cardboard, food waste, yard waste, rubber, leather, textiles, wood, and small amounts of glass, metals, and plastics. Most of the inert (uncompostable) materials are screened out before the compost is released for use. The largest compostable portion of Florida MSW is paper.
Yard trimmings include leaves from trees and shrubs, pine needles, grass clippings, tree bark, woody branches, roots, and shredded prunings. After January 1992, Florida YT waste could no longer be accepted in a Class I landfill, so composting YT became an attractive option.
Biosolids are the solid portion of waste from municiple sewage treatment plants. Composting biosolids creates heat that can be used for the pathogen reduction required before it can be land-applied. Biosolids are often mixed with MSW ot YT to create a co-compost, because the N added by the biosolids accelerates the raw material composting process.
Florida MSW composts are regulated under Rule 17-709, "Criteria for the production and use of compost made from MSW" (DEP, 1989), which provides general guidelines for the compost user and producer. Presently, Rule 17-709 is in a review process for modification. While environmental regulators are mainly interested in compost trace metal concentrations, growers have different interests once compost has passed regulatory health and safety standards. From a commercial grower's point of view, compost quality is judged on moisture concentration, nutrient concentration, pH, soluble salts, organic matter concentration, C:N ration, water holding capacity, bulk density, cation exchange capacity, particle size, presence of weed
seeds, and odor. Most benefits of soil-applied compost have been attributed to improved physical properties due to increased organic matter concentration rather than nutrient value. Optimum chemical and physical parameters for composts that might be used in vegetable crop production are listed in Table 2.
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