Perennial crops require less intensive farming practices and less energy to grow than traditional biofuel crops which not only need to be planted each year, but typically require more fertiliser, herbicides and pesticides. This means less chemical residue ends up in the soil and less CO2 is produced.
The FP7-funded 'Enhancing biomass production from marginal lands with perennial grasses' (GrassMargins) project has been set up with the objective of developing and testing new perennial grass strains which can be used in biofuel production on marginal land.
“Perennial grasses have been extensively used in Europe and the US but mainly in regard to combustion processes,” says Dr Susanne Barth, the GrassMargins project coordinator. “We are looking at selecting and breeding new varieties suited for use on marginal land, and identifying optimal growing environments to make them more economically viable as biofuel raw materials.”
While many grasses have evolved naturally to survive in flood and drought conditions, GrassMargins is identifying novel varieties of grasses which show even higher and more stable levels of productivity and increased stress tolerance, thereby reducing the risk of crop failure.
The objective is to select and breed new varieties especially for growth in marginal habitats that are less suited to conventional agriculture, making perennial grasses an attractive crop option for the agricultural sector.
Food versus fuel?
While the benefits of perennial grass as a biofuel are many, the GrassMargins team has identified a need to convince stakeholders that this crop is not only economically viable, but also sustainable and ethical because it can be grown alongside food crops – addressing the ‘food-versus-fuel’ argument.
First, farmers who may be considering supplementing their income from food crops with biofuel production harbour concerns about the risk of using valuable arable land to grow perennial grasses. The GrassMargins team has been researching the exploitation of marginal land – areas which are of poor quality for agriculture and which yield poor returns for the farmer.
“Our partners are actively involved in providing news and information through bio-energy conferences, open information days and practical advice to farmers who could be in a position to harness the potential of their marginal land to grow perennial grasses,” continues Dr Barth.
Perennial grasses can grow almost anywhere, even on poor-quality ‘marginal’ land, which means more arable land can be reserved for food crops. Using marginal land also benefits the surrounding arable land by helping to retain soil nutrients and reduce erosion.
Dr Barth explains that farmers are not the only stakeholders the project is targeting with its dissemination campaign. While there is interest among the farming community, an increase in perennial grass production depends on whether local governments are aware of the benefits and are providing incentives and legislation to encourage the growing of crops for alternative energy.
She adds that the problem of getting the harvest to refineries, which turn the raw material into biofuel such as ethanol, albeit one indirectly linked to the work of the project, also remains as much a political issue as a logistical and environmental one.
Building refineries and boilers locally to produce biofuels could help reduce the amount of transportation needed, which could otherwise quickly negate the positive economics of biofuel production. “Having boilers and combined heat and power (CHP) plants in proximity to crops would make production and refining more efficient”, says Dr Barth, “but again there has to be support and incentives from local government level for this to happen.”