Manure (also known as livestock manure) is organic matter, mostly derived from animal faeces and urine, but normally also containing plant material (often straw), which has been used as bedding for animals and has absorbed the faeces and urine. In the Nitrates Directive (Council Directive 91/676/EEC), it is defined as "waste products excreted by livestock or a mixture of litter and waste products excreted by livestock, even in processed form".Dairy, beef and swine manure may be either solid or slurry. Horse and poultry manures are solid.
The distinction between solid manure, liquid manure and slurry is in part related to how they are handled in the farm. But the need to separate these different types while collecting Integrated Farm Statistics data is also related to their different chemical environments and consequent effect on emissions. When the conditions are insufficiently aerobic (for nitrification) or insufficiently anaerobic (for denitrification) nitrous oxide is likely to be formed. As liquid animal manure is a strict anaerobic substrate (due to its very low redox potential, its high biochemical oxygen demand and the slow oxygen diffusion into animal manure), nitrification cannot occur, apart from the superficial surface layer. As a result, nitrate is absent in liquid animal manure. Solid animal manure, on the other end, is accessible for diffusion of oxygen, so nitrification and denitrification will occur. Because nitrous oxyde production requires an initial aerobic reaction and then an anaerobic process, it is theorized that dry, aerobic management systems may provide an environment more conducive for nitrous oxyde production (Jun et al., s.d.)
Solid manure, including farmyard manure, are excrements, with or without litter, of domestic animals including possibly a small amount of urine. Solid manure has at least 20% dry matter. It is handled with front-end loaders and/or pitchforks.
Farmyard manure is a decomposed mixture of dung and urine with straw and litter used as bedding material and residues from the fodder fed to cattle, sheep and other livestock (excluding chicken). It is a form of solid manure.
Liquid manure is urine from domestic animals including possibly a small amount of excrement and/or water. Liquid manure has up to 4% dry matter and can be handled as a liquid with normal irrigation equipment. Liquid manure with less than 1% solids (such as in properly designed anaerobic and aerobic lagoons) can be handled using conventional centrifugal pumps (MWPS, 2004).
Slurry is manure in liquid form, a mixture of excrements and urine of domestic animals, including possibly also water and/or a small amount of litter.
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Related concepts
- Capacity of storage facilities for manure
- Cover of storage facilities for manure
- Incorporation time of manure
- Type of manure application
