Litter chemistry
From Poultry Hub
Two of the main elements affecting litter chemistry are Nitrogen and Phosphorous.
Contents |
Nitrogen
Poultry manure contains two main forms of Nitrogen (N): uric acid and undigested proteins, which represent 70 and 30 per cent respectively of the total nitrogen.
Under aerobic conditions, uric acid and undigested proteins break down into ammonium, which is probably why it has often been referred to as ‘hot’ waste. The degradation process occurs quickly, with microorganisms being a fundamental component in determining the rate of conversion. Once applied to land, ammonium quickly converts to nitrite and finally nitrate, the most readily available form of N that plants can use.
In contrast, anaerobic decomposition of uric acid and undigested proteins is slower and results in the majority of N in litter being in the ammonium form. Often the storage of litter results in 50 to 90 per cent of the total N being present as ammonium by the time it was applied to land.
Phosphorous
Phosphorus (P) concentrations in broiler diets are maintained to ensure rapid animal growth, and consequently manure usually has high P concentrations. Reported P concentrations in litter are variable, ranging from 9.8 to 27.1 g/kg, with the majority in a soluble form.
Further information
- Kelleher, B. P., Leahy, J. J., Henihan, A. M., O’Dwyer, T. F., Sutton, D. & Leahy, M. J. (2002). Advances in poultry litter disposal technology – a review. Bioresource Technology 83, 27–36.
