The research project ABC4Soil (advanced biochar based fertilizers for multiple ecological benefits in soil conditioning) has worked towards the development of a new generation of potent organic fertilizers, based on the recycling of farm and forest residues. The potential of agricultural and forestry residue, both in Norway and in Germany, has been mapped and based on this, several feedstocks for the practical biochar production selected. The feedstocks, including forest residues, bark and straw, were transformed into biochar, using different reactors and production conditions. The production conditions (including temperature, heating rate and residence time) that yielded the most promising biochar properties defined. The produced biochars have a porous structure, suitable for carrying nutrients. These nutrients were provided by soaking the biochar with liquid organic residues (e.g. animal manure and other nutrient rich biogenic liquids). This process impregnates the biochar and immobilizes nutrients in the porous structure. These so-called advanced biochar (ABC) based fertilizers were tested in a large number of greenhouse tests on annual food crops, and the best outcome used as a basis for large-scale field trials. In addition to growing food, ABC fertilizers have also been used in the planting of urban trees. Throughout the project, a large amount of data has been collected. This data has been used to understand the interdependencies of feedstock, reactor, production conditions, plant and soil type and fertilizer efficiency. The project is currently still ongoing and expected to be finished in December 2021, after which the project results will be made available to interested audiences.
Dr. Kathrin Weber
SINTEF Energy, Norway