Mechanical slurry separation is fast becoming of interest to livestock farmers throughout the island of Ireland.
The technology was featured at the recent slurry management event, hosted by the College of Agriculture, Food and Rural Enterprise (CAFRE) on the Banbridge dairy farm of William McClelland.
In attendance was David Whelehan from Vogelsang Ireland.
He confirmed that on-farm separation systems will be of interest to all livestock farmers with finite slurry storage capacity, and also to those wishing to make best use of low emission spreading systems (LESS).
Slurry separation
“Spreading a liquid means that a crop can absorb the nutrients becoming available to it almost immediately,” Whelehan explained.
“In addition, the loss of ammonia to the atmosphere is greatly reduced. Separating out slurry solids also means that no fibrous material is coating the leaves of the growing plant.
“This is important in a grassland situation, where grass is taken back from the fields and ensiled.”
According to Whelehan, separated slurry solids can be used by tillage farmers to build organic matter, phosphate and potash levels within their soils.
“In this context, separation technologies are very much at the heart of the nitrates debate. Also, the slurry solids can be easily transported over significant distances.”
Slurry separators can be grant aided under Targeted Agriculture Modernisation Schemes (TAMS) from a number of perspectives. However, a typical screw press model will require a three-phase electricity source.
Design
“Typically, we are looking at a three-phase, seven and a half kilowatt motor. Machines are designed to be very user-friendly, and have very low running and maintenance costs,” Whelehan added.
Most farms, however, do not have a three-phase electricity supply.
“Bigger dairy farms, particularly those using robots and having a back-up generator will have access to a three-phase electricity supply,” Whelehan commented.
“In these cases, the option would be to have the separator permanently installed.
“The other alternative, would be to source a contractor who would come in, when required, with a mobile separation unit.”
The typical separator that would be used on Irish farms is rated to process 50m3 of slurry per hour.
“Cattle slurries produced in Ireland tend to be that much thicker. So, in reality, the actual capacity would come back down to 30m3 of slurry per hour.
“It is possible for a stone to get through and hit the screen that is located within the separator.
“However, screens tend to be divided up into three sections. This approach acts to minimise the cost of any damage that might be caused by an incoming stone,” he concluded.