Waste and Nutrient Management
(chapter
16 in McGlone and Pond)
Manure is pig feces and urine with spilled water and feed and other materials (ex., hair, vermin, junk). Manure used to be called Waste; now it is recognized as a source of valuable crop nutrients.
Most commercial pig farms are a CAFO under US SPA rules. Units are exempt from the CAFO rules if:
- There are fewer than 2,500 pigs of 55 lb or more or
- If pigs are in confinement for 45 days or more per 12 months or
- If vegetation or crops can not grow due to the heavy animal density
Manure nutrient production can be significant:
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How many gallons per day does one 2,500-sow unit produce?
That unit would have 3/20 groups in farrowing and 17/20 groups in gestation.
2,500 X (3/20) 0.15 X 4.0 gallons/day = 1,500
+
2,500 X (17/20) 0.85 X 1.1 gallons/day = 2,338
----------
3,838 gallons per day
1,400,870 gallons per year
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What is in manure?
- Water (H & O)
- Carbon (can be released as CO2 or CH4)
- Nitrogen
- P
- Other minerals (K, S and many others)
Movement of nitrogen through the environment
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Haw can Manure be handled?
- Dry form
- Outdoor
- Indoor with bedding
- Liquid form on solid floors
- Very uncommon on modern farms (older open gutter flush systems)
- Liquid form under slotted floors
- Under floor storage
- Under floor flush
- Flush tank
- Pull-plug system
- Under floor scraper
- Others
Liquid manure storage and handling options
- Aerobic or anaerobic?
- Slurry-storage tanks
- Covered lagoon
- Under-floor pit
- Other