Pelleted biochar: Chemical and physical properties show potential use as a substrate in container nurseries

We found that peat moss, amended with various ratios of pellets comprised of equal proportions of biochar and wood flour, generally had chemical and physical properties suitable for service as a substrate during nursery production of plants. High ratios of pellets to peat (>50%) may be less desirable because of high C:N, high bulk density, swelling associated with water absorption, and low volumetric water content, whereas a mixture of 75% peat and 25% pellets had enhanced hydraulic conductivity and greater water availability at lower (<−10 kPa) matric potentials. Adding pellets to substrates used to grow plants in nurseries has potential to add value to biochar and thereby improve economic viability of pyrolysis. Moreover, biochar-amended substrates offer opportunity to sequester carbon as part of the normal outplanting process.