Swine producers who have limited acres available for land application of liquid manure and whose land has phosphorus content above 60 - 70 pounds per acre should consider separation. Separated effluent that has 90+ percent of the phosphorus removed can be land applied as a fertilizer according to the separated effluents nitrogen content without concern for the phosphorus concentration. The phosphorus concentration of unprocessed swine slurry limits the amount of slurry that can be used as a fertilizer at an amount below the manures nitrogen value. Swine producers who must haul liquid manure one or more miles to land apply the slurry should consider separation. It costs one cent or more per gallon to haul slurry each mile. Separated effluent can be land applied at higher rates because of reduced phosphorus concentration. At the Illinois State University Farm - Lexington, separated effluent has been applied at rates up to 25,000 gallons per acre while maintaining a negative phosphorus balance.
Swine producers who have limited land base upon which to apply unprocessed slurry may want to consider separation. The Illinois State University Farm - Lexington swine facility contains a 200 sow farrow to finish operation. Prior to separation, land application of the liquid manure generated by the facility required 200 acres. With separation, all of the separated effluent can be land applied on 40 acres without concern for phosphorus pollution. The separated biosolids produced through the separation process are composted and sold off-farm for 20 dollars per wet ton.