Mr Brendon Costello1, Dr Bing Han1, Prof Deli Chen1, Dr Clayton Butterly1
1Faculty of Veterinary and Agricultural Sciences, Unversity of Melbourne, Parkville, Australia
Poultry meat production generates large amounts of organic waste. Poultry litter, which consists of manure, bedding material (e.g. wood shavings), feathers and spilt feed, is a valuable source of organic matter and nutrients that may be used as a fertiliser or soil amendment to improve soil chemical and biological properties. Nitrogen (N) has the greatest economic value of the nutrients found in poultry litter and the amount and stability of this N is critical to ensure the successful reuse of this waste product. However, large amounts of N may be lost from poultry litter via ammonia (NH3) volatilisation thereby reducing the quality of the waste product, its value and the potential for reuse after leaving the broiler house. Birds do not produce urine but rather excrete N in faeces in the form of uric acid (C5H4N4O3), which is rapidly hydrolysed to urea (CH4N2O) and subsequently NH3 following manure deposition onto litter. The rate at which NH3 is volatilised and lost to the environment is highly dependent on broiler house conditions, such as litter pH and temperature. Lignite has been shown to be highly effective at reducing N loss in beef cattle feedlots due to its low pH and high cation exchange capacity (CEC). However, its effectiveness in poultry systems has not been established. Other novel litter amendments such as modified black coal may also prove effective. Oxidisation of black coal can change its surface chemistry, generating high concentrations of acidic oxygen-containing functional groups, thus reducing pH and increasing CEC. The availability and low cost of these amendments warrants further investigation of their efficacy. This research aims to investigate innovative methods to reduce N loss from poultry litter in broiler houses, improve the nutrient value of the waste material and facilitate increased reuse of this important source of nutrients and soil organic matter.