Water-soluble fertiliser for food crops derived from biogas digestate

Modern farms that grow food crops in soil-free solutions present a valuable and sustainable source of leafy greens, such as lettuce and spinach. Unlike traditional farming systems that grow crops in soil, modern farms are totally reliant on the application of synthetic fertilisers to supply nutrients essential for plant growth.

The sourcing of synthetic fertiliser has fast become an economic and environmental concern. The production of synthetic fertiliser is responsible for 1-2% of global energy use and its prices are susceptible to large increases. For example, since the beginning of the Russia-Ukraine conflict, British fertiliser prices have increased by 139% in the last 12 months.

Our company, Future Greens, specialises in sustainably growing leafy green food crops in a soil-free system. As a solution to the aforementioned problems, this project aims to develop a process for converting waste produced from anaerobic digestion (AD) into a high-quality water-soluble fertiliser suitable for food crops. AD has the double benefit that it can contribute towards our company's energy demands, reducing our environmental impact.

To achieve this aim, our company has teamed up with researchers at The University of Sheffield in Biosciences and Engineering, who are experts in microbial phosphorus cycling and anaerobic digester design, respectively.

Successful development of our innovative idea would provide a cost-effective, low-carbon alternative to synthetic fertiliser for UK's farming industry while unlocking additional revenue for AD plants, contributing towards the UK's goal of a circular phosphorus economy, and building resilience in the UK food industry.