High quality silage essential for efficient AD plant operation

High quality silage essential for efficient AD plant operation

“Having consistent, good quality maize silage all year makes running the 1.3 MW AD plant easier and more efficient,” says Matthew McDowell, AD Manager of Barley Brigg Biogas at Stradbroke, Suffolk.

Matthew studied Agricultural Technology at Queens University, Belfast and completed his dissertation on anaerobic digestion before moving to England to work in the sector.

The plant uses on average 30 tonnes of maize silage per day, making up 45% of the total feedstock. The feedstock also includes straw and solid/liquid manure from the adjoining 480 sow pig unit. Herb waste from a nearby factory and sugar beet pulp are used seasonally, plus a small amount of poultry manure.

AD plant clamp

Barley Brigg Biogas is owned by Rattlerow Farms, the Stradbroke based pig breeding/genetics company who farm 3000 acres of arable land adjacent to the AD plant.

They, as well as 6 other local farms, grow 650 acres of maize a year for the plant. The maize is all grown within a 4 mile radius of Barley Brigg and contract harvested, with Matthew managing the harvest and crop maturity to achieve the target 33% dry matter (DM).

Yields over the years have averaged 40-45 tonnes/hectare, chop length 3/4mm, and correct consolidation is given high priority. Harvest hours are restricted from 7am to 9.30pm in respect of local residents.

AD plant

Matthew has found that the more attention to detail they give to making better silage the better the smooth operation and productivity of the AD plant. Timely harvesting and rapid clamp covering all contribute to this as well as the use of Silostop Max 1-layer oxygen barrier film.

Matthew first encountered this Silostop film in his first job with Agrigen biogas, a 3.5 MW plant at Rendlesham, Suffolk. “I was unimpressed with the results of the polyethylene film Agrigen were using and we trialled the new Silostop film I had seen advertised, “he said, “the results were impressive and they have used it ever since.”

Both Agrigen and Barley Brigg AD plants use Silostop Max every year on all of their silages. These and other consumables are sourced from Fram Farmers who also supply other products and inputs to Rattlerow Farms.

Matthew finds the Max film very strong and easy to use for the covering team, and has resulted in eliminating top waste and reducing DM losses in the top layer. He also places high importance on using Silostop heavy duty Wall Film in conjunction with the Max, and is now using Silostop Supacova Nets for protection on top of the film. A rotary defacer is used for taking silage out of the clamp, leaving a smooth tight face to reduce DM losses from secondary fermentation.

The larger 150m long Max rolls are now used at Barley Brigg, as Matthew finds that less joins are much more effective for covering large clamps. He also values the technical support and back-up from Silostop, with their wide experience helping farms make better silage all over the world.

Silostop Max is available in 35/50/150/300m lengths with widths from 8 to 27m. The larger 150 and 300m rolls have 1m increments marked on the film to allow accurate cutting of the film to fit the clamp, and to show how much film is left on the roll.


Maize silage is the only silage feedstock used at Barley Brigg, so it is very important to make the best possible. Forage rye was previously used, but Matthew has found that the smooth running and feeding of the plant is more easily achieved with one high quality feed stock with minimal variation and consistent analysis.