Table 6. Compost Quality Is Currently Characterized by Current Parameters Studied in the Literature.

Physical	Odor, color, temperature, particle size, and inert materials
Chemical	C, N analyses	C/N ratio in solid and water extract
	Cation exchange capacity	CEC, CEC/total organic-C ratio, etc.
	Water-soluble extract	pH, EC, organic-C, ions, etc.
	Mineral nitrogen	NH4-N content, NH4-N/NO3-N ratio
	Pollutants	Heavy metals and organics
	Organic matter quality, humification	Lignin, complex carbohydrates, lipids, sugars, etc. make up the organic composition
		Elemental and functional group investigations, molecular weight distribution, the E4/E6 ratio, pyrolysis GC-MS, NMR, FTIR, fluorescence, and other methods define humification indices and humic-like substances
Biological	Microbial activity indicators	O2 uptake/consumption, CO2 production, self-heating test, and biodegradable components
		Enzyme activity (phosphatases, dehydrogenases, proteases, etc.)
		ATP content
		Nitrogen mineralization–immobilization potential, nitrification, etc.
		Microbial biomass
	Phytotoxicity	Germination and plant growth tests
		Others: Viable weed seed, pathogen, and ecotoxicity tests