Influence of turning and water addition on ammonia emission in farm piles composting

In the last years several technologies have been developed to reduce the environmental impacts of rearing livestock farms (Burton, 2007). Composting is one of these techniques. It is a simple technique and it is able to enhance the physical and chemical characteristics and management of manure (Bernal, 2008). Composting is carried out on heaps with turning or non-turning strategies. The main environmental impact of the composting process of high nitrogen content organic wastes is the ammonia (NH3) emission, a green house gas (GHG), released into the atmosphere (Szanto, 2007). NH3 emission during composting process of organic materials depends on many aspects concerning the physical and chemical characteristics of the materials, the environmental conditions and the different processing strategies adopted. Temperature, pH, C/N ratio, initial ammonium nitrogen (NH4-N) content and moisture are the main parameters affecting the final NH3 losses. This paper reports results on NH3 emission from composting process of mixtures of swine manure solid fraction and sawdust carried out in piles and adopting two different turning strategies.