Digestate: for healthy soil and customised fertilization

Anaerobic digestion is a sustainable process that converts animal manure and plant waste streams into energy and digestate. As an end product, digestate contains important nutrients such as nitrogen, phosphorus and potassium, which are returned to the soil, completing the natural cycle. Because easily degradable carbon has already been converted to biogas, digestate stimulates soil organisms that can cope with more difficult to degrade carbon, and digestate contributes to the buildup of stable organic matter. During digestion, much of the nitrogen is converted to ammonium, a form of nitrogen that is easily available to plants in the soil. The trend is to separate the thick and thin fractions in the digestate. The thick fraction can be used as a soil conditioner to apply tailored organic matter and improve soil structure. Excess phosphate can also be concentrated and disposed of via the thick fraction. Nitrogen can be recovered from the thin fraction by stripping as a fertiliser replacement. This not only allows precision fertilisation, but also reduces the use of fossil fertilisers.

We offer specialised services in digestate production, quality and application. By mapping the properties of digestate, we can advise on how to further optimise the digestate itself, as well as the digestion process. We use field research to answer questions about digestate, fertiliser and soil health. For example, a recent study we conducted showed that digestate from cattle manure has a positive effect on the fungus Trichoderma, which is known for its disease-fighting and plant growth-promoting properties.

For entrepreneurs:We help digestate producers and buyers by mapping the properties of digestate. Through chemical analysis, we provide insight into relevant parameters such as: presence of macro- and micro-nutrients; mineralisation of nitrogen; chemical status of phosphate; carbon-nitrogen ratio; amounts of organic matter; dissolved organic matter; humic compounds and effective organic matter; energy content; residual gas potential; chemical and biological oxygen utilisation. We calculate the digestion efficiency of your installation on the basis of the digestate and biogas production. We can also map the biological properties of the digestate through microbiome analysis. Based on the complete insight gained from these analyses, we advise on digestate utilisation and on optimising digestion processes to further improve digestate quality.

For governments:We can help governments answer questions about digestate, fertiliser and soil health. We do this by conducting field research on the effects of different types of manure and digestate on soil biology, soil chemistry and crop yield.