Pit Digester Manure Analysis

Pit Digester | Manure Treatment


Two double-long 2,000 head finishing buildings on the same finishing site were tested during 2010 for manure fertilizer values. One 2,000 head was treated with Pit Digester and the other 2,000 head building was left untreated. Neither building had ever been subjected to any form of manure treatment in the past. In addition, the pigs were being fed phytase. After 10 months of maintenance treatment in one barn, manure samples were pulled from both buildings during the pumping process. The values indicated below reflect an average of two samples taken from each side of the double-long and then averaged to reflect a better representation of the entire pit composition. Manure samples were independently sampled and analyzed by a third party.

Untreated
Treated
Sample I.D
Site 1 (1E/1W)
Site 1 (2E/2W)
Manure Analysis
2000 head wean/finish 1
2000 head wean/finish 2
Test Results
Dry Matter
2.55%
4.20%
Moisture
97.45%
95.80%
Pit Level post pump
11.50”
12.25”
Lb. per 1000 Gal.
Lb. per 1000 Gal.
Nitrogen
40.25
53.15
P2O5
7.70
17.45
K2O
28.30
35.75
Sulfur
2.90
3.75
Ammonia
34.90
38.20
Nitrate
0.15
0.29
Ca
2.90
5.80
Mg
2.90
5.80
Cu
0.10
0.15
Fe
0.60
0.95
Mn
0.10
0.20
Zn
0.80
1.05
Sodium
6.20
7.50

12.90 lbs N per 1,000 gallons x $0.53 N/lb x 960 (000) gallons = $ 6,563.52
9.75 lbs P per 1,000 gallons x $0.69 P/lb x 960 (000) gallons = $ 6,458.40
7.45 lbs K per 1,000 gallons x $0.42 K/lb x 960 (000) gallons = $ 3,003.84

Total gain in fertilizer value (2000 head wean to finish): $16,025.76
Total gain in fertilizer value (1000 head wean to finish): $ 8,012.88

Discussion

The results clearly show that the building treated with Pit Digester had a higher nutrient analysis in every category analyzed, including 100% increases in trace minerals Calcium, Magnesium and Manganese. In addition, the percent moisture decreased and the dry matter in solution increased, demonstrating a significant increase in manure consistency. Pit Digester was able to solubilize nutrients and enable them to be pumped out for use in the fields.

The volume was calculated using a volume of 12,000 gallons per inch in the deep pit. The pit is 96 inches between the slats and the floor of the pit. However, instead of using 96 inches (8’) to calculate volume pit depth, a figure of 80 inches was used due to the fact that there were about 4 inches between the slats and the liquid when the manure was pumped and 12 inches of manure was left in the bottom when pumping was completed. Eighty inches of pit depth multiplied times 12,000 gallons per inch equals a volume of 960,000 gallons per pit.

The treated building was covered in a bubbling film that showed that solids were being fermented in the bottom of the pit. The untreated building showed no evidence of fermentation and, therefore, no mixing and suspending of solids. The manure application crew foreman was asked to comment on the consistency of the manure and he said that “the two pits pumped very differently. The Pit Digester pit didn’t really need much mixing and had greater consistency....it was thick, but it moved.”

In Conclusion

Pit Digester was able to increase the nutrients available to be pumped out for fall fertilizer application by releasing nutrients from the sludge layer. Between the untreated pit and treated pit, NPK parameters were increased 32%, 126% and 26% respectively. As a result, the value of the manure increased by over $16,000 in the pit treated with Pit Digester in NPK. The contract producer was very pleased with the results.