Improved Manure Storage

Objectives Reduction of the leakage of minerals from animal housing and manure storage into ground water and surface water Storage of manure to allow timely application on the field in accordance with the nutrient requirements of the crops Reduction of the evaporation of ammonia causing acid rains from animal housing and manure storage | Objectives Technique Costs Targeted Livestock System Impacts Context of Application Monitoring: EIA, Indicators References Photos of Examples

Techniques

Construction of well-sealed manure tanks made of concrete and sealed with a strong plastic cover, the manure storage should be emptied in time and prevented from overflowing onto land or surface water. The size of the manure storage should be sufficient to store manure for sufficient time to comply with local regulations for manure spreading and to match the nutrient requirements of the crops. Storage space required does depend on the quantity of wastewater (water spilled during drinking, water used for cleaning, and rainwater entering the manure storage). Adequate mixing equipment is required to empty the manure storage through pumping.

Standards in The Netherlands for quantities of manure mix (including manure and urine but excluding any wastewater) produced by livestock per annum are:

- Adult dairy cows: 23,000 lt
- Fattening cattle(1 –2 years) 10,000 lt
- Sows with piglets 4,700 lt
- Fattening pigs 1,100 lt
- Broilers 11 lt
- Layers 87 lt

(Source: Central Bureau of Statistics in The Netherlands)

Reduction of air circulation by installing a cover on the manure storage will reduce the emissions of ammonia into the atmosphere.

Specially designed covers over manure storage will capture biogas (methane) formed through anaerobic decomposition of the organic matter in the manure. This process will work better in warmer climates.

Note: The experience with the capture of biogas direct from manure storage is limited.

Costs

The cost depends very much on the local situation (e.g. general construction cost, soil quality, regulations on manure storage) In The Netherlands, a storage capacity enough to hold 6 months manure production is required. Costs for manure storage are about US$ 50 per cubic metre.

Requirements are for about 5 cubic metres per sow and 1 cubic metre per fattener. This is very dependant on the quantity of water used for cleaning (including rainwater). For poultry the requirements are very variable, depending on the housing systems and manure storage systems used (wet, dry, deeplitter, artificial drying etc). Manure production per dairy cow is around 20 cubic metres. The storage requirement depends on specific regulations and production system. In the Netherlands a storage capacity is required of between 12 - 20 cubic metres per cow.

Targeted Livestock System

Proper manure storage is required for any livestock production system where livestock is kept in confinement and manure has to be stored for any length of time. In particular for the industrial livestock production systems and for the Mixed, cut and carry and for the Mixed, external feed systems.

Grazing System

LGA | LGS1 | LGS2 | LGS3 | LGH1 | LGH2 | LGH3 | LGT1 | LGT2 | LGT3
N | N | N | N | N | N | N | N | N | N

Mixed System

MCG | MCR | MCC | MFF | MEF
N | Y | Y | Y | Y

Industrial System

IFP | IPL | IPG | IRM | IDU | ISL | ITN | IMP
N | Y | Y | Y | Y | Y | N | N

Impact

- Positive Environmental Impact

- Reduced point pollution of land and ground and surface water through the leakage of minerals from manure.
- Increased possibility to introduce and control a system of balanced application of manure to land.
- Manure storage allows for timely application of manure according to the requirements of the crop.

- Negative Environmental Impact

- Free air circulation above manure storage causes emissions of ammonia into the atmosphere.
- Methane is formed in anaerobic conditions in manure storage pits and can escape into the atmosphere.

- Livestock Productivity Impact (groups: milk, reproduction, meat, health, feed)

- Improved storage of manure does not have a direct impact on the productivity of livestock; the impact is indirect through the improved growth of fodder crops which benefit from the improved manure application.

Context of Application

Policy context: regulations for the storage of manure, and the development of specifications for manure storage (storage capacity, quality of construction and lengths of period of storage), coverage of storage.

Education/training: Explanation to the farmers of the need for proper manure storage and technical specification of the manure storage.

Monitoring: EIA, Indicators

- Construction quality of manure storage
- Percentage of farms with adequate manure storage
- Regular control of manure storage for leakage and overflow

References

Agricultural Biological Engineering, Environmental Protection Agency and Purdue University (Minesota) http://danpatch.ecn.purdue.edu/~epados/farmstead/manure/src/title.htm

Ministry of Agriculture, Food and Rural Development of Ontario, Canada: Storage of liquid manure
http://www.gov.on.ca/omafra/english/livestock/swine/facts/94-097.htm

B.L. Harris, D.W. Hoffman and F.J. Mazac, Jr. Reducing Contaminatioin by Improving Livestock Manure Storage and Treatment Facilities. http://waterhome.brc.tamus.edu/texasyst/texasystworkbooks/printedb6030a.html

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