A method for producing biochar particles or pellets which use sulphur and other additives. The method includes producing a mixture with biochar and additives selected from sulphur, lignin, and gluten. The mixture is mixed with water and passed through an extruder to produce an extrudate. The extrudate is then cut into pellets. The pellets are then tumbled/spun with each other and heated to result in mostly spheroidal pellets whose mechanical characteristics allow them to be used with well-known agricultural equipment. The biochar can be produced with sulphur incorporated as an outer coating. To produce this sulphur coated biochar, the method includes feeding a biomass feedstock to a pyrolysis reactor, pyrolyzing the feedstock into biochar particles, size-sorting the biochar particles, and coating the biochar particles with the sulphur coating material.