Building a natural ‘circular economy’ for agriculture’s future

William Gilder
22 August, 22
Amidst the turbulence the agricultural industry is currently weathering, understanding the true value of what may have once been seen as ‘waste’ has previously untapped potential to deliver some stability.

Amidst the turbulence the agricultural industry is currently weathering, understanding the true value of what may have once been seen as ‘waste’ has previously untapped potential to deliver some stability. As a company with proud farming heritage, William Gilder Group is witnessing the beginnings of an evolution of agriculture first-hand and as managing director, William Gilder, explores, these all contribute to the transition to a circular economy model.

No sector is immune to external disruptive forces. Amid the rising cost of fertiliser prices as one of the many consequences of the Ukraine conflict, and continuing pressure to reduce environmental impact, effective and sustainable agricultural methods need to be maintained in order to lessen these intense burdens.

Much has gone into researching the impacts of alternative fertilisers versus crop yield and quality. A research paper published in June 2022 suggests that both sustainable farming practices and reducing the agricultural sector’s reliance on chemical fertilisers do not impact yield. In some cases, such as the adding of manure, the yield of crop actually increases, while returning nitrogen to the soil, and thereby improving its fertility. A step in the right direction, definitely, especially with farmers under pressure to mitigate environmental impacts in their activities.

Even more encouraging is that the components to produce these fertiliser types are often within accessible reach. Sludge, slurries, and organic waste are all naturally produced throughout the agricultural activity chain, yet many farmers are struggling to comprehend the value it holds. Liquid digestate, as one example, is frequently used as a nutrient-rich fertiliser, formed as a natural by-product of anaerobic digestion (AD). In other words, the breaking down of waste matter.

The digestate can cost as low as £3 per tonne to the farmer in some cases versus to the £731 per tonne for imported synthetic ammonium nitrate, and research conducted by Scotland’s Rural College (SRUC) in 2020 calculates that the value of the nutrients within digestate themselves to be around £134 per hectare. The missing link is improving access to the AD facilities needed to treat the waste matter in the first place.

While technically possible, it is rarely feasible nor practical for farm owners to have their own, large-scale anaerobic digestor facility capable of treating enough waste matter for mass production of digestate on their land. To compensate, fertilisers are instead stored in specialised containers or tanks, according to specific legal guidelines and protocols before it is either spread or distributed to locations elsewhere.

Agronomists trained according to industry certification such at the nationally verified Fertilisers Advisers Certification and Training Scheme (FACTS) can bring vital knowledge in these areas and guide on the most relevant solution for the farm’s specific characteristics, and the storage lagoons follow regulations in accordance with the Environment Agency.

Fertilisers such as digestate also have the added benefit of returning essential nutrients to the soil, in particular, readily-available nitrogen. Healthier soil, of course, results in healthy crops, and with the proper application of digestate, this can continue to be the case year on year. Continued positive soil health drives back returns for the farm and strengthens the local supply chain at the same time. With so many benefits from a comparatively accessible source, why is digestate not being used more widely?

A short answer is, quite simply, the cost. Though figures vary, start-up costs of between £750 000 and £1 million are not uncommon for a slurry and manure treatment or storage facility, which is what would likely be the case for a farm. In such unpredictable times, a guaranteed return on investment as well as demonstrating good sustainability practice has to be a given before deciding to forge ahead. Then there are the expensive consequences should landowners unknowingly spread material outside of the rules.

Incentives have been introduced to facilitate wider distribution of equipment to aid spreading, such as grants for dribble bars, in order to help farmers with applying digestate in accordance with the PAS 110 accreditation guidelines, which we’ll come onto, but is a lack of information holding back potential?

The Farm of the Future: Journey to Net Zero report published by The Royal Agricultural Society of England (RASE) earlier this year adds that increasing fertiliser efficiency, particularly that of organic sources such as digestate, and improved soil health forecasting will both be key for meeting future environmental goals and at the same time, ensuring the needs of the land itself are met.

Undoubtedly, agriculture is a crucial industry for the long-term sustainability of the environment and our daily lives. And even in a climate crisis, trust in farming still remains high, though work is needed to support this vital sector to realise its potential for becoming best in class when it comes to sustainability. A circular economy approach – making the most of resources and maximising efficiency, while at the same time limiting waste and what could be perceived as being ‘harmful’ practices – provides numerous opportunities for agriculture operators to work sustainably, in both the environmental sense and for society overall.

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