Industry consultants are advising farmers to explore the benefits of spreading digestate as a cost-effective and nutritious alternative to fertiliser.
As bought-in fertiliser continues to be eye-wateringly expensive, SAC Consulting – part of Scotland’s Rural College (SRUC) – has spent six months researching digestate and producing guidance for its use on Scottish farms.
However, it is also advising land managers to be aware of the risks involved in spreading the product and how to mitigate them.
Researcher Fiona Salter said: “We know that many farmers are struggling right now with the rising costs of fertilisers, and we hope that we can provide insight into the nutrient benefit of using digestate appropriately and how to calculate the fertiliser replacement value.”
They are spreading the message via podcasts on Farming and Water Scotland’s website, one of which hears first-hand from William Rose of Mid Coul Farms near Inverness..
He grows grass, cereals and pulses on 1300ha and fattens 800 cattle. The farm also has two AD plants and he spreads the digestate produced there on his land.
He said: “Using digestate has really transformed our ability to grow bigger yields and more consistent crops, so it has been a big boon and if we can achieve our objective of using no bought-in fertiliser at all, even on relatively small areas, particularly in the current climate, then we would feel very satisfied.”
He has invested heavily in the operation with specialist tankers and “nurse” holding tanks in his fields. And while he says digestate has added organic matter into the ground and improved the structure of his soils, he advises farmers to read the guidance as spreading the material is challenging.
He added: “You must have accurate spreading equipment and must at least have a dribble bar or some form of injection. Being able to spread accurately and only where it is needed, is essential.”
To hear the podcasts and download the guidance document visit www.farmingandwaterscotland.org/soil-nutrients/anaerobic-digestion-digestate/digestate-use-on-scottish-farms/