| Energy
The role of on-farm
anaerobic digestion
in a post-CAP world
By Charlotte Morton, Chief Executive of the Anaerobic
Digestion & Bioresources Association (ADBA)
t the end of
February, the
Department for
Environment, Food
& Rural Affairs
(Defra) published
its consultation ‘Health and
Harmony: The Future for Food,
Farming and the Environment in a
Green Brexit’. As the consultation
that will help to decide the future of
farming support in England once
the UK has left the European
Union and the Common
Agricultural Policy (CAP),
Environment Secretary Michael
Gove is right to describe it as a
‘once-in-a-generation opportunity
to shape future farming policy’.
There will be as many different
ideas as to what post-CAP farming
support should look like as there
are farmers in England, but the
consultation makes it clear that
Defra’s priorities are supporting
public goods (such as rural
resilience and climate change
mitigation), high environmental
standards, and innovation and
new technologies to increase
productivity.
ADBA welcomes these aims,
which are vital for ensuring that
farming in England is
environmentally and financially
sustainable in the post-Brexit era.
It’s vital, however, for there to be
coordination between changes to
farming support and Defra’s
recently published 25 Year
Environment Plan, which seeks,
amongst other objectives, to
improve the quality of the UK’s
soils and reduce pollution and
waste from agricultural operations.
The role of AD
This is where anaerobic
digestion, often known simply as
‘AD’, comes in. Anaerobic
digesters recycle agricultural
wastes such as manures, slurries,
and vegetable off-cuts and convert
purpose-grown energy crops into
renewable heat and power, low-
carbon transport fuel, and nutrient-
rich digestate, which can be
applied straight to land as a
natural fertiliser. AD provides farms
with an additional income stream
(through the ability to sell excess
energy to the grid), a treatment
option for wastes and cover crops,
and a home-grown alternative to
buying expensive and
environmentally damaging artificial
fertilisers.
While on-farm AD is often talked
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about in terms of the on-site
energy it generates for farming
operations (providing power, heat,
cooling, drying, and vehicle fuel),
there is a vast array of non-energy
benefits to AD that are often
overlooked:
AD reduces emissions from
rotting manure, farm wastes, and
slurries and replaces
petrochemical-derived artificial
fertilisers, abating significant
amounts of carbon;
It supports farmers by
diversifying their income and
reducing input costs;
It improves food security
through supporting profitable crop
rotation and the recycling of
nitrogen, phosphorous,
potassium, and trace elements
through the spreading of digestate
back to farmland;
Digestate increases organic
matter, improves soil structure,
and reduces water demand, soil
degradation, and runoff; this helps
restored soils to act as a carbon
sink;
The UK AD industry currently
employs 3,500 people and has the
potential to employ a further
15,000 in the agricultural sector
and 30,000 more widely; and,
The AD industry develops low-
carbon technology and expertise
that can be exported to global
markets, particularly important for
the post-Brexit economy.
How AD benefits farmers
To date, the non-energy benefits
of AD have not been linked to
financial support mechanisms,
with support only provided for
energy generated. While
incentivising energy generation is
important in helping to meet policy
goals set out in the government’s
Clean Growth Strategy, a new
farming support policy offers the
government the opportunity to
reward the AD industry for helping
to meet its wider farming policy
goals, particularly restoring soils
and encouraging sustainable food
production.
For example, AD is an ideal
component for profitable crop
rotation. Through converting them
into valuable on-site renewable
energy, AD helps make break
crops profitable for farmers, while
maintaining and enhancing
biodiversity. Farmers can
incorporate crops for AD into their
rotations, increasing subsequent
yields of food crops, or grow them
on unproductive marginal land.
Use of cover crops for AD can also
prevent persistent problems such
as nematodes and black grass.
Use of digestate on farmland,
meanwhile, has been proven to
maintain pH and soil fertility,
improving crop yields and the
availability of nutrients whilst also,
significantly, reducing reliance on
expensive, carbon-intensive,
imported artificial fertilisers.
Digestate-derived fertiliser is now
available in over 200 Homebase
stores, indicating that a market is
s tarting to open up through which
farmers can make a profit from
their digestate.
The way forward
In ADBA’s response to Defra’s
consultation, we will be talking
about the above examples and
providing evidence on the benefits
AD and digestate can bring to
farmers, as well as highlighting the
wider impact this has on food
production and the environment.
Defra is clear that, post-Brexit,
farms will need to improve their
environmental performance,
particularly in terms of reducing
emissions, restoring soils, and
becoming more self-sustaining.
ADBA is clear that AD can and
should make a significant
contribution to these goals, and
we’ll be making the case to the
government that through
supporting on-farm AD, it can
ensure a profitable and
sustainable future for UK farming.
You can find out more about
ADBA’s work at
adbioresources.org
April 2018 | Farming Monthly | 35