Effects of Carbon to Nitrogen Ratio and Turning Frequency on Composting of Chicken Litter in Turned-Windrow Piles

Raw chicken manure was co-composted with sawdust in turned-windrow piles to understand the effects of carbon to nitrogen (C:N) ratio and turning frequency (TF) on composting. Carbon to nitrogen ratios of 20:1, 25:1 and 30:1, and turning frequencies of every 2 days and every 6 days were experimented. Properties of the chicken litter (chicken manure + sawdust) periodically monitored during the composting process were moisture content (MC), temperature, pH, total nitrogen (TN), total carbon (TC) and C:N ratio while dry matter (DM), total phosphorus (P) and total potassium (K) were examined at the end of composting. During composting, MC of the piles was periodically replenished to 55%. The results showed that C:N ratio had significant (p ≤ 0.05) effect on pile temperature, TN, TC, C:N ratio, DM, P and K while TF had significant (p ≤ 0.05) effect on pile temperature, pH, TC, C:N ratio and K. A significant part of the TN losses were attributed to NH3 volatilization while that of the TC losses were attributed to OM degradation. It was observed that moisture loss increased as C:N ratio and TF increased. All treatments reached stability at about 87 days as indicated by the decline of pile temperatures to values close to ambient temperature

Fate of compost nutrients as affected by co-composting of chicken and swine manures

Passive aeration co-composting using four mixtures of chicken manure and swine manure at 1:0, 1:1, 3:7 and 0:1 with sawdust and rice husk was carried out to study the effects of co-composting on the physicochemical properties of the organic materials. The experiment, which lasted 66 days, was carried out in bins equipped with inverted T aeration pipes. The results showed that nutrient losses decreased as the proportion of chicken manure in the mixtures decreased for saw dust and rice husk treatments. This indicates better nutrientst conservation during composting in swine than chicken manure. Manure mixtures with rice husk had higher pile temperatures total carbon and total nitrogen losses, while manure mixtures with saw dust had higher total phosphorus loss and carbon to nitrogen ratio. Composts with rice husk demonstrated the ability to reach maturity faster by the rate of drop of the carbon to nitrogen ratio