According to Viel et al. [21] the increase in total N may be due to the dry mass net loss as
the loss of organic C as CO2 during composting.In addition, the N values might also increase due to the nitrogen-fixing bacteria activity that commonly occurs at the end of composting.Although a decrease of N can occur due to leaching of NO−3-N and ammonia volatilization, in this experiment, both piles were covered with plastic to retain the moisture and avoid moisture from outside, which could lead to the result obtained.