best available technologies for manure treatment - Baltic Green Belt

Best Available Technologies for manure treatment baltic sea 2020
Best Available Technologies for manure treatment baltic sea 2020
ANNEX E: TABLES WITH SHORT DESPRIPTION OF LIVESTOCK MANURE TREATMENT TECHNOLOGIES
Best Available Techniques for manure treatment - for intensive rearing of pigs in Baltic Sea Region EU Member States Technical Report "Best Practice Manure Handling, Phase 2"
Ref No. 41 Composting
Brief description
Composting of solid manure is a form of aerobic treatment which can occur naturally in livestock manure
heaps. High porosity (30 – 50 %) is required for sufficient aeration.
Temperatures in the compost heap are between 50 and 70 ºC and kill most of the pathogens. Compost
with a dry matter of up to 85 % can be produced. Suitability for application depends on the structure of the
manure, but requires a minimum dry matter content of 20 %. Typical livestock manure heaps do not satisfy
the requirements for thorough composting. With controlled application, manure is composted in stacks of
a size that suits the aerobic conditions and the use of machinery.
Best results are obtained by using well-chopped straw and solid manure in the right proportions and by
controlling temperature and moisture content in long narrow ‘windrows’. Composting can also be
performed in a barn (e.g. pre-dried manure). Specific systems have been developed that consist of a
combination of tanks with aeration and stirring equipment to enhance the fermentation process and
containers or boxes for further fermentation and drying. Properly composted solid manure significantly
reduces the volume of material spread to land and the amount of odour released. For easier handling,
pelletizing is applied in addition to composting.
Description of the effect on leaching (positive or negative) of N
and P
Composting is done in order to make livestock manure stable,
i.e. able to transport and store without further moulding or
fermenting, without seeping, and without evaporations.
Further, the purpose of composting comprises advantages as
being a cheap way to reduce the water amount, and a
possibility to kill weed seeds and pathogens.
The effect on leaching is negative: Barrington et al. (2002)
have reported that N losses from pig/straw manure through
seepage is between 12 and 22%, and that further 31 to 57% N
is lost during the composting as emissions of N
2
and N
2
O, in
total a loss of 53 to 69% of the N.
Composting of livestock manure in closed containers would
probably make the economy in this technology even worse.
Innovation stage
Research
Pilot
Practice
Major references
Ministry of
Agriculture, Food
and Fisheries. 1996
Barrington et al.,
2002
Investment price,
Basic Variable
For a composting plant that treats
2,000 tonnes manure with 1,360
tonnes sawdust and producing 1,800
tonnes compost:
For a turned windrow system, an
appropriate tractor and turner
could easily cost 35,000 to
40,000.
If buildings are constructed for
all four activities (mixing,
composting, curing and storage),
total construction costs could be
82,000 to 100,000 for an
operation of this size.
Condition for leaching reduction
effect
Composting has no leaching
reduction effect – on the contrary,
the process itself is often reason for
leaching.
No data
Operational costs,
per tonnes
Around 20 as an
average,
depending on the
efficiency.
Certainty of information
Prices Low
Effect on leaching High
per kg saved N
or P leaching
The question
cannot be
answered because
there is a negative
effect on the
leaching.
Complexity of implementation
Composting can be organised on every farm,
however, there exists more advanced and industrial
composting technologies, which probably have a large
economy of scale.
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