Agriculture

Role of AD in farming

AD has a central role to play in climate smart farming, improving slurry management, reducing GHG emissions and costs, improving crop yields and producing a renewable biofertiliser which can be applied to land replacing energy intensive artificial fertilisers.

AD systems are able to treat almost any organic waste, crops, animal by-product material and more. Using AD on farms could reduce costs and greenhouse gas emissions from waste treatment and slurry storage, as well as providing revenue from the energy and digestate generated.

Government policy

The government and The Committee on Climate Change (CCC) are generally supportive of the role that bioenergy could play in the UK economy. In December 2011, the CCC noted that bioenergy is needed to meet our 2020 renewables target as well as longer term CO₂ reduction targets. Their Bioenergy Review also outlined that the role of bioenergy must be analysed on the basis of total lifecycle emissions for different feedstocks, including both direct and indirect land use change impacts.

Government largely echoed these positions in their Bioenergy Strategy in April 2012, setting out a framework for future support of bioenergy. However, they also stated that they had some concerns over crop-only AD plants, which were to be tackled through an industry lead code of conduct.

What is the impact of growing crops for AD?

PGCs for AD aid the sustainability of farming operations and offer one of the most efficient forms of bioenergy available. Environmental issues associated with crop growing are the same as for crops grown for any other purpose, and can be managed through good farming practice. PGCs can be grown as break crops which also promotes biodiversity as a wider range of crops in any given rotation will have different characteristics. Their growth as a break crop can also improve soil quality and improve the yields of other crops in the rotation.

Evidence shows that at current levels and projections of deployment any concerns over displacing land for food production are unwarranted. In the UK there are 1.226 mha of temporary grassland and 9.901 mha of permanent grassland available for food production, whilst there are approximately 860,000 ha of marginal or idle lands which has the potential to produce 4.8 mt of biomass for energy production. This unused land has the potential to supply grass silage for AD without displacing any arable land used for food production.

Farming Best Practice Guidelines are already in place which ensure that PGCs are grown sustainably for renewable energy production. These include Standards of Good Agricultural and Environmental Condition (GAEC), Good Agricultural Practice for Nutrients and Fertilizers and Farm Assurance Schemes, and the Assured Combinable Crops Scheme.

For further details please see ADBA’s position papers on purpose grown crops in AD and anaerobic digestion and nutrients.