There has been much debate about the net benefit of growing energy crops to reduce greenhouse gas emissions. While it is accepted that energy crops can displace fossil fuel imports, the emissions from the cultivation of energy crops were until now uncertain.
Teagasc has carried out a number of research projects to quantify the greenhouse gas emissions associated with these crops.
One of the surprising findings of the research was that the conversion of grassland to biomass, which was previously thought to lead to large soil carbon losses, in fact maintained or improved the carbon balance through higher annual carbon sequestration rates and lower than expected carbon losses from ploughing.
“Perennial biomass, such as miscanthus and short rotation willow coppice, can form part of a sustainable solution to Ireland’s future energy requirement. At the same time this will offset part of the greenhouse gas emissions within the agricultural sector”, explains Dr Gary Lanigan at Teagasc’s Environment, Soil and Land Use Department at Johnstown Castle.
However, challenges remain, explains Dr Lanigan: “The government’s target is to supply 12% of national heat demand through co-firing with renewable resources by 2020. But, it takes years for energy crops to mature and to reach maximum sequestration potential. Therefore, urgent policies are required to encourage large-scale adoption of these systems.”
“To incentivise the growing of energy crops, financial mechanisms would need to be put in place to allow agriculture to benefit from the greenhouse gas reductions associated with fossil fuel displacement. “Perennial biomass crops are ideally placed to be incentivised through an initial Domestic Offsetting scheme,” concludes Dr Lanigan.