2020/4/1/ · Therefore, evaluation the quality of large-scale composting is urgently needed. Compost maturity is often tested using single-factor index such as temperature, NH 4 +-N, NO 3 –-N, nitrification index (NI), cation exchange capacity, and germination (GI) (Xiao et al., 2017). While those indexes can describe compost maturity to some extent, the