Winner : Andrew Rennie of Gask Farm, Turriff
Andrew farms in partnership with his parents John and Monica.
The main aim is to be more sustainable, reduce impact on the environment, become less reliant on the world's resources and utilise what is already there.
The Rennie family with the Lord Lieutenant of Aberdeenshire and their Award Plaque.
In the background - the dome of the Anaerobic Digester
The result is a carbon neutral company.
In 2004 they took the decision to diversify with a difference. After having visited several farms in Germany, they built an Anaerobic Digester (AD) in 2006. It was built without any funding or assistance. As this was a new concept of energy production for the UK at that time, it was an uphill job to pull everything together to get it through planning. They had to work very closely with the local environmental health office, SEPA and the State Vet Service (SVS) to gain all the permits and licences required. This was made all the more difficult due to the fact this was the first AD plant to be built at that time in Scotland and that the permits and licences were still in draft format
The idea was to utilise waste streams from the local abattoir and blend this with the pig slurry to create a rich natural fertilizer and a renewable energy source at the same time. The process produces 15,000 tons of digestate per year and off-sets the carbon footprint by making 340kw/hour of renewable electricity. 12% of this power is used to run the site and the rest is exported into the national grid. This all works in harmony with the rest of the farming enterprise, which off-sets the carbon footprint by using the digestate as a replacement for inorganic fertiliser. This reduces the bought in Nitrogen by 90% and compounds by 85%. The digestate is analysed and spread on to the various cereal crops depending on their need. This natural fertiliser has been pasteurised to comply with Animal By-Product Regulations. The process uses the waste heat, which is captured when generating the electricity (by doing the pasteurisation this way the energy that is already contained in the slurry is used to clean it up from any pathogens which may be present ---- no fossil fuel needed).
There are various application methods for the digestate,
All seed beds for winter and spring crops have the digestate injected in. This locks in the nutrients and reduces evaporation.
In the spring, to comply with the PEPFAA code all spring applications made to the winter barley / wheat and oil seed rape are applied with a dribble bar and this is fed by an umbilical system, which reduces soil compaction.
The tractor that is used for sowing the crops has now been fitted with an auto-steering system to increase accuracy for the placement of the tramlines. This then leads to more accuracy when spreading the digestate onto the growing crop and removes the chance of overlapping.
The nitrogen in the digestate is analysed and when it is pumped out to the field it goes through a flow meter so that the required amount of nitrogen is applied.
Crop yields have been maintained and in some cases increased.
These cereals are harvested and stored on the farm and used to feed the pigs for the next year. Once fed to the pigs, the green renewable cycle begins again with the slurry going back to the AD plant.
Many people have visited the farm already to see how the system works and there are farmers in Scotland – and south of the border too – who have come to look at how to blend slurry with other wastes into an AD system such as this one. Andrew says: "The satisfaction in seeing our ideas translate into other peoples’ farm systems and the confirmation of the benefits of our farming practices in winning the Future Farming Award is great.”