Working out the precise carbon dioxide emissions of growing a bioenergy crop could return a healthy premium, according to Richard Martin, technical manager for Farmway.

There is no requirement to calculate the exact carbon footprint of a bioenergy crop, but it was likely to become compulsory in the next few years and could offer financial incentives, he said at a recent press briefing.

“The Renewable Energy Directive means fuels will have to contain components from sustainable sources and big fuel companies will be offered incentives to use grain from low carbon footprint crops. Our hope is that these will be passed onto farmers.”

The firm had developed an online carbon calculator in conjunction with consultancy firm Five Bar Gate that allowed farmers to calculate the true carbon footprint of their crops, he said. “Farming Footprints is a web based system for determining the precise amount of carbon dioxide emitted when growing a bioenergy crop.”

Default carbon footprint figures are used at present, but these vastly over-estimated the quantity of carbon dioxide emitted from a crop, said Five Bar Gate consultant, Ian Waller. “You can get as much as 100% improvement on the default figures as they are extremely conservative.”

The farmer provided cropping information, such as yield, nitrogen use, cultivation technique and soil type, and the system generated a certificate with a carbon emission rating in g of carbon dioxide per tonne. This certificate could be traded with grain and could return the grower a healthy premium, said Mr Martin. “The big unknown is how much the big oil companies will pay, but it could be tens of pounds per tonne.”

Artificial nitrogen rate and yield had the greatest bearing on crop emissions, said Mr Martin. “But while high nitrogen can increase emissions per tonne, these can be diluted by higher yields.”

Real data had already been loaded into the system, but Farmway was appealing for growers to join up to a free trial and see what their carbon emissions ratings were. “It means farmers can get ahead for free before this becomes compulsory.”

There would eventually be a charge for the system, but it was too early to determine what this would be, he said. “We need to work out what value the system is to the farmer before we can set a price.”

The system allowed bioethanol plants such as Ensus to download a carbon footprint certificate for every load of wheat they bought, said Mr Waller. “It would be nice to see a greater value for low carbon wheat.”