Impact of anaerobic digestion on soil organic carbon contribution of organic residues

Biogas is often highlighted as a conversion technology that enables energy recovery of all kinds of organic materials while closing important loops for e.g. of plant nutrients, carbon and water.

This usually involves the utilization of digestate as fertilizer in agriculture.

The contribution of digestate to soil organic carbon (SOC) built-up is an important factor in the carbon footprint of biogas production.

• But how does anaerobic digestion affect the contribution of organic materials such as straw and manure to SOC in comparison to the undigested soil application?
• And can we predict the SOC contribution from new organic by-products that originate from e.g. fractionation of digestate, manure and sludge?

The Biogas Research Centre has invited four experts from SLU to shed light on the processes that affect the stabilization of carbon in soil.