Where there’s muck there’s…. problems oh and opportunities. Diffuse pollution and a future energy source but how?

Farm Yard muck store just above the lake and the main water courses.

A few organisations have just started working on a joint project to deal with diffuse pollution from farm-yard manure through the use of Anaerobic Digesters (AD) but using something called a Dry AD approach, which is not as it sounds it should be called ‘dryer’ AD. The challenge we are dealing is that with a lot of farm muck stores being outdoors and within water catchments a lot of the nutrients are washed out and down into water courses and case a lot of problems for us, wildlife and general ecology (eg the toxic blue-green algae we have been suffering from in some lakes, low water quality, low in fish and wildlife) Conversely the farm and food in general needs these nutrients to grow.

why AD? generally covering most of the rural areas would a) be prohibitively expensive with most small farms not able to afford and b) generally change the look of the things we hold most dear our countryside. but could also have an income stream but at worst be cost neutral going down the small AD route But the main challenge for a Farm Yard Manure (FYM) AD system is that a cow has already taken out most of the energy from the grass and so what will the bacteria within FYM live on? For this feasibility we are looking at adding crops such as soft rush, bracken and generally anything which is a non food crop and its management can enhance biodiversity and or food production. The other advantage is that we also get to manage the nutrients in the system and apply them at the right time of year in the right way to the crops which needs them.

From my side, I am interested in diffuse pollution element but methanee management as a climate changing gas and also the energy elements through the production of biogas.  Especially with the move from fossil fuel in the next 20 or so years and to see if the farm could supply itself and the next range of tractors, use in a generator for heat and electricity generation in the farms and so on

For this work we are working with Seven Wye Energy Agency (Biomethane Regions), University of Wales (Wales centre of excellence for Anaerobic Digestion) Snowdonia National Park Authority. Thanks to Arloisi Gwynedd (EU Leader) for part funding this feasibility study with additional resources from the EU Biomethane Regions in three of our farms. As ever more to come!

Arwyn the NT Farm manager thinking muckie thoughts. “I wonder about the nutrient flow, storage and practicality within our farm”?

This entry was posted in climate change and tagged anaerobic digestion, andy bull, Arloisi Gwynedd, biomethane regions, diffuse pollution, environmental, Fit for the future, hafod y llan, Keith Jones, National Trust, National Trust Blog, Paul Southall, sustainability, Wales, water. Bookmark the permalink.

One Response to Where there’s muck there’s…. problems oh and opportunities. Diffuse pollution and a future energy source but how?

  1. Richard M says:

    Hi Keith,

    I recently went on a guided tour around a Anaerobic Digester in Wrexham at Lodge Farm. The farmer and owner of the system Richard Tomlinson is a font of information on the actual operation of the digester, he went to great measure to explain the different rates of gas produced by various waste streams. I believe he mentioned that broiler chicken waste was particularity productive, as the chickens do not have sufficient time to digest the food so the waste still contains a good deal of nutrients for the anaerobic process. He had some interesting pie charts showing the gas produced by various waste stream and was also keen to explain the benefits of, using both the liquid and solid digest-ate on his farm, which is a organic operation.

    Whilst on the tour of the plant he was showing a method they use for removing grit and debris from the bottom of the tank, which apparently they were prototyping. He was also willing to allow people to climb the top of the tank and have a good look at the process taking place.

    The gas generated at this project was being used to power a CHP plant, although I have no idea how they were using the H/W Co-generated, as the farm was remote from any district heating schemes. I have been wondering if there is any merit in using some of the excess hot water during the winter months to provide gentle background heat to maintain the digestion process, or possibly having a half buried tank to try to keep a constant temperature for most of the year.

    Anyhow , some food for thought,

    Hwyl Fawr,



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