Equipment that separates manure into solids and liquids is expensive and must be considered carefully by dairy and hog producers before they take the plunge.
Jennifer Neden, a nutrient management specialist with Alberta Agriculture, said she knows of nine manure separators installed on Alberta farms in the last two to three years.
Producers need a cost-benefit analysis to decide about installing a system that can cost $50,000 for the equipment and often more than $100,000 for a building and related equipment.
“There’s been a big flush of them come into the system and I think one of the reasons why is because the (federal Growing Forward) program offered a cost share on installing these systems, and that made the economics that much more viable,” Neden said in an interview at the Manure Management Update in Lethbridge Jan. 14.
The program will provide up to $50,000 to producers for installing a separation system.
Dairy producer Brian Stoutjesdyk decided the cost would be worthwhile. He installed a screw press separator two years ago when costs skyrocketed for sawdust bedding.
He now he uses the dewatered dairy manure for bedding, supplying his own needs and those of two other farms.
Neden said bedding can be a big expense for dairy and hog operations, and separation is an option.
“I think the way that guys are running their numbers is if they do recycle the bedding, they look at what their current bedding costs are and for some guys, they’re paying $1,200 a month. For what? Just for bedding. So if they incorporate those savings into paying off their piece of equipment, I think the return makes more sense.”
Neden said the screw press separator is the most popular, although fan separators and systems connected to composters have also been installed.
The screw press is more effective when there is higher dry matter content, which makes it better with dairy manure than hog manure.
Besides bedding, the solids can also be composted or used as fertilizer. The solids tend to retain phosphorus, while much of the nitrogen remains with the liquid.
That requires producers to manage the different products according to soil needs, said Neden.
Separation of the solids makes them more economical to move and apply because of their nutrient concentration. The solids have less odour when the liquid is removed, which can be a consideration.
The liquids are thinner, easier to pump and may be suitable for fertigation.
However, Neden said the high initial cost, need for facility modifications and the energy and maintenance requirements are important considerations.
“There’s also two waste streams to manage, and this is something that sometimes producers forget.”
Animal numbers and manure volume are key to determining whether manure separators will pay off.