Moreover, DHAF showed a relatively moderate EC change in the initial stage of fermentation
owing to lower accumulation of organic acids. With the degradation of small organic molecules and increase in the pH value, the total ions continued to decrease, leading to a decline in EC. It has
been suggested that EC less than 3.5 mS/cm is optimal for the use of composts as fertilizers in agriculture. As shown in Fig. 1, the final EC value of each pile was lower than
3.5 mS/cm, indicating that the products had good quality.