Compost Specifications
Link to this table

Parameter Parameter Definition Range
Source material/ Nutrient content Typically biosolids/animal manure, source separated compostable materials or sorted yard wastes Nitrogen: 0.5 – 3

Phosphorus: 0.5 – 1.5

Potassium: 0.5 – 1
Maturity Level of completeness of the composting process Seed emergence and seed vigor = minimum 80% relative to positive control
Stability Biological activity in the composted material CO2 evolution rate: < 8 milligrams CO2-C per grams organic matter per day
pH Acidity/alkalinity 5.5 – 8.5
Soluble salts The amount of soluble ions in a solution of compost and water Varies widely according to source materials for compost, but should be < 10 deciSiemen per meter (millimhos per centimeter)
Organic matter The amount of carbon-based materials 30-65% dry weight basis
Particle size Size of particles Pass through 1-inch screen or less
Biological contaminants Pathogens (disease causing organisms) and weed seeds Meet or exceed US EPA Class A standards, 40 CFR Section 503.32(2) levels
Physical contaminants Man-made materials (like pieces of plastic or glass) that do not compose, also called ‘inerts’ < 1% dry weight basis
Trace metals Elements that can be toxic to humans, animals or plants Meet or exceed standards for Class I compost set in Minn.R. 7035.2836, Subp. 6, (A)

This page was last edited on 16 April 2020, at 15:50.