More than 250 delegates from across Europe and around the world will gather in Wexford next month to discuss a range of scientific research topics with potentially profound importance for the future environmental performance of Irish agriculture.
The biennial Ramiran (Recycling of Agricultural, Municipal and Industrial Residues in Agriculture Network) conference is being hosted by Teagasc and will focus on new cutting-edge strategies and technologies to improve the efficiency of manure and residue management on farms.
This has implications far beyond the farm gate, according to Teagasc research officer and conference co-host Dr Karl Richards. "Agriculture accounts for one third of Ireland's greenhouse gas emissions," he says. "By tackling manure management as much as 3-4 per cent of national emissions can be addressed and that could make a significant contribution to meeting our targets for greenhouse gas reductions."
One of the key papers at the conference will address the question of extracting value from agricultural and other waste streams. Presented by Vincent O'Flaherty of NUI Galway, "Future advances in waste and organic residue valorisation" will look at the potential for manures and slurries to become a valuable resource for the production of renewable energy and nutrients for agriculture.
“The conference is not just dealing with agricultural manure, it will look at other organic residues such as waste water sludges and so on”, says Richards. “It is important to remember that this is not just waste, it is full of nutrients and carbon which are good for crops and can be put to other uses. For example, Vincent O’Flaherty will look at ways to add value to organic waste. One of the ways that’s being looked at is the use of anaerobic digestion to extract energy. You put the manure or other waste in a stainless steel digester along with a microbial community. This breaks it down into methane and other component. The methane can be used to fuel a combined heat and power plant or it can be piped into the gas grid.
"This is an important energy source in countries like France and Germany", he adds. "In Ireland, there is no special incentive to produce energy in this way. They value this in other countries and offer incentives for it. That should be considered here as well."
Energy isn’t the only form of valorisation which will be explored. “You can extract different chemicals from manure as well,” Richards points out. “We’ll be looking at cutting-edge technologies which take waste products and extract valuable products from them while reducing pathogen levels and greenhouse gas emissions.”
Manure management
Phosphorous is a case in point. “A challenge in Ireland in manure management is the requirement not to add phosphorous to soils which don’t require it,” he notes. “By removing phosphorous from manure you can end up with two valuable resources. You have the phosphorous which is a finite resource globally and you have the remaining manure which can still be used as a fertilizer.”
The same technology can also be used to remove phosphorous from wastewater streams. This could be very important as phosphorous is one of the key nutrients involved in the eutrophication of rivers and water catchments in Ireland. Removing the pollutant at source could make a real difference.
Research in this area could also have wider economic benefits. "There is some very interesting work going on in Galway at the Biorefinery Ireland Enterprise Ireland research centre," Richards points out. "Not only are they doing work to develop technologies to valorise Irish manure and waste the technologies can be sold globally as well. They can sell treatment options to other countries around the world."
And there is real demand for these technologies. “In some countries in the world the only fertilizer they have is manure or other organic residues,” he explains. “In warmer climates where tilling the soil releases a large amount of carbon the soils don’t hold water very well. New ways of composting organic wastes and more advanced value-adding treatments for manure are being discovered and are in great demand around the world.”
Richards's colleague Gary Lanigan points out that methane is not the only gas to be dealt with and how the conference can assist the agricultural sector in meeting the challenges presented by climate change.
“One of the biggest emissions is around ammonia. About half of our ammonia emissions come from manure storage and spreading. There is a lot of research going on into this. For example, sileage effluent is very acidic and this can be added to manure either prior to or during spreading to reduce ammonia emissions. There are quite a few strategies you can employ where you don’t necessarily have to reduce agricultural activity to reduce greenhouse gas emissions. You start with the animal and how it’s managed, its diet and so on. Then you move on to storage and spreading methodologies and technologies.”
