Manitoba Agriculture Food and Rural Initiatives reports gravity based solid liquid manure separation offers an opportunity to reduce manure processing costs and the amount of land required for spreading.
A team of researchers constructed an approximately 40 foot long, eight foot wide and four foot deep metal storage tank.
The tank was fitted with sampling ports at various depths, filled with liquid swine manure and samples were collected as the solids settled to determine how fast the phosphorus settled out.
Gary Plohman, with Manitoba Agriculture Food and Rural Initiatives, says a total of three trials were conducted.
We did find that solids and phosphorus settled out quite rapidly in the manure.
The greatest amount of setting occurred over a period of about two days and the larger particles settled out during that time.
The longer we left the manure, the finer particles had time to settle out.
So we started off with, in some cases, phosphorus levels that were as much as eight pounds per thousand gallons that, over the period of the test, had reduced down to two pounds per thousand gallons.
The same thing for solids, we started off with something that was initially somewhere in the range of five to seven percent solids and over the time that it was settling it reduced down to about one percent solids in two of the trials.
Plohman notes some of the alternatives examined in Manitoba are fairly expensive.
He says farmers who need to reduce phosphorus applications to comply with new manure management regulations are interested in this approach because it offers an effective and possibly economical way to remove phosphorus from manure and reduce the land base required for spreading.
Source: Farmscape.Ca
