## 4 Discussion  
### Temperature, Matrix pH and EC Variations  
Temperature affects the biological activities that take place during composting. The gradual heat development at the beginning of composting is an indication of a slow biodegradation process and could be attributed to the manual aeration procedure, which lasted continuously for a week. According to [PERSON] et al. [36], organic materials, together with microbial communities and the activities of biodegradation, are activated upon pile turning. However, manual turning also disorganizes microorganisms, requiring extra time to build up new communities for heat mobilization and reactivation [37]. Heat production was low in the MC at 45%, suggesting an unstable biological process by the treatment. With an insufficient moisture content, pile dehydration easily occurs, which inhibits biological processes [38]. Optimizing the moisture content of the piles improves the matrix structure of organic materials for microbial degradation [39]. According to [PERSON] et al. [40], microorganisms have high preference for compost piles that are sufficiently moisturized and thus promote and retain high temperatures over a longer period.  
The mineralization of organic matter and the emission of NH\({}_{3}\) (results shown) were responsible for the rapid increase in pH during composting [41]. Aside from that, the large emission of CO\({}_{2}\), decomposition of organic matter and the nitrification process (results shown) which converted NH\({}_{4}\)\({}^{+}\)-N to NO\({}_{3}\)\({}^{-}\)-N were also key in the decline in matrix pH [42]. During organic matter degradation, organic acids are inevitably produced, which decreases the pH of the compost pile [14]. From the study, the matrix pH was lower in the 65% moisture content because of the high biodegradation of organic matter by the treatment. Microorganisms use compost carbon (30-40%) as an energy source for cell mass maintenance and development, and in return, excrete a significant amount of stock carbon as waste during the process [43; 44]. As carbon is excreted, the pH of the decomposing materials also decreases [45].  
The electrical conductivity reflects the degree of compost salinity and the phytotoxicity effect on plants [45]. The observed increase in EC with composting time was attributed to the decomposition of organic matter (results shown) that released mineral salts in the form of ammonium and phosphate ions during composting [46]. Subsequently, the initial decline in EC was attributed to the emission of NH\({}_{3}\) (results shown) in the early stages of composting [47]. The substrate EC generally decreases with increases in moisture content [48]. High compost moisture influences higher neutralization of soluble salts than compost with low moisture. This phenomenon may explain the low EC observed at 65% moisture and the high EC observed at a MC of 45%. Producing compost with EC values between 2.8 and 3.0 mS/cm means that each moisture level was effective in diluting the soluble salts associated with compost heaps for microbial consumption [49]. The alternating pattern between the EC and pH could be due to the characteristic difference in ions between the indexes. Electrical conductivity is dependent on negatively and positively charged ions, while that of pH is dependent on specific ions (i.e., hydrogen) in the solution [50].