Biochar pellets produced by blending switchgrass biochar, lignin and fertilizers K and P together followed by pelletization were characterized and investigated for their ability to release K and P. Pellets processed at 180 °C with increasing lignin content from 10 to 30 wt.% had higher density, thermal stability and durability, and produced lower pore volume and smaller pore size than pellets processed at 105 °C.