Increasing Nutrient Efficiency From Anaerobic Digestate

Anaerobic digestion has become an attractive technology for many farmers, enabling them to convert biomass as feedstock into biogas and digestate (ADD), both of which are valuable resources.
To support its members explore this subject, Agri-TechE sponsors and coordinates the ‘Increasing Nutrient Efficiency From Anaerobic Digestate’ field lab on behalf of Innovative Farmers.
The field lab is investigating how to stabilise N and reduce loss in AD. This includes improving absorption and soil structure using cover crops.
All farmers in the group produce their own digestate on-farm and are specifically interested in exploring how to stabilise its nutrient content and decrease loss through leaching or volatilisation when applied as a fertiliser.
The field trials were set up in collaboration with research partner Niab and are running over two growing seasons with four different treatments that explore N fixation with cover crops:

• digestate + cover crop mix
• digestate only
• cover crop only
• control.

Data collected from the trials, including soil health measurement, nutrient content and yield, will provide a better understanding on the role of cover crops in maximising the value of digestate.
Alongside the field trials, one of the farmers in the project, a keen agricultural engineer, is building a DIY digestate acidifier to reduce volatilisation.
A detailed progress of the project can be found on the dedicated field lab page on the Innovative Farmers website. Agri-TechE sponsors and coordinates this project.
Research partners include Niab and Cranfield University.