On the use of biological and chemical indexes for determining agricultural compost maturity: Extension to the field scale

A comparative study of a bench-scale and a pile composting showed that the C/N, ash percentage and alakaline phosphatase activity were potentially useful parameters for estimating the maturation of cattle manure compost. The values of these parameters were nearly constant during a simulated poor composting, whereas they changed significantly during an optimal process. Other parameters—decomposition degree, chemical oxygen demand, invertase and Rusch number—were less sensitive indicators of composting. The use of these data for agricultural compost samples has shown that high alkaline phosphatase activity and No₃⁻/NH₄⁺ ratio were correlated with compost maturity.