Gravity offers potential approach to managing phosphorus
March 26, 2009, Winnipeg, Man. – Research conducted on behalf of the
Manitoba Rural Adaptation Council has found gravity based solid liquid
manure separation offers a potential low cost approach to phosphorus
March 26, 2009, Winnipeg, Man. – Research conducted on behalf of the Manitoba Rural Adaptation Council has found gravity based solid liquid manure separation offers a potential low cost approach to phosphorus management.
Working in partnership with Niverville, Man., based Puratone Corporation, a team of researchers constructed a metal storage tank about 40 feet long, eight feet wide and four feet deep and fitted one end with sampling ports at various depths.
The tank was filled with liquid swine manure, samples were collected at various levels as the solids settled and analyzed to determine how rapidly the phosphorus was settling out.
Dr. Geza Racz, a professor emeritus with the University of Manitoba says three trials were conducted aimed at identifying a low cost approach to managing phosphorus.
“Basically we measured the settling over many days,” said Dr. Racz. “We didn’t know exactly how rapidly it would settle out initially and we found that within about one or two hours the phosphorus in the upper top layers actually started to settle out and within a period of about 48 hours most of the phosphorus in the top three to three and a half feet of manure had settled to the bottom of the tank.”
“We thought that this was fairly rapid and that some producers could use this in terms of separating the phosphorus from their liquid manures before they put the liquid into the storage lagoon for example.”
Dr. Racz believes this approach may have a place, particularly for the smaller producer, in economically separating the liquids from the solids as a means of managing phosphorus.
The research is not yet complete, he admits. Researchers still need to figure out the best way to utilize the solid portion of the manure that contains most of the phosphorus, he says.