Received: 23-09-2019 / Accepted: 28-02-2020
The study was conducted to assess the effect of C: N ratio (T) and frequency of turning (D) on total nitrogen loss during chicken manure composting (chicken faeces, leftovers, feathers and sawdust) to achieve good quality compost. The ratio C: N included three levels of 20: 1, 25: 1 and 30: 1 and the frequency of turning was 1, 3 and 5 days/time. The initial physical and chemical properties of chicken manure were determined. During composting process, 55% moisture in the pile was maintained, monitoring temperature, pH and total nitrogen (TN). Total dry matter, total carbon (TC), total phosphorus and total potassium were recorded at the end of the composting process. The study results have shown that the ratio of C: N and the frequency of turning to affect significantly (p ≤0.05) to the pile temperature, the change in pH, the lost amount of TN, TC, P and K while the weight of the dry matter was only affected (p ≤0.05) by the C: N ratio. All experimental treatments were reached maturation after 75 days when the pile temperature decreased close to the ambient temperature. The total amount of nitrogen loss was mainly due to evaporation of ammonia gas (NH3) in the first 20 days after composting when the pile temperature and pH reached 30oC and 7.5. The experimental treatment of turning every 3 days, the C: N 25:1 ratio (D3T25) has the lowest total nitrogen loss.