Role of biochar in promoting circular economy in the agriculture sector. Part 2: A review of the biochar roles in growing media, composting and as soil amendment

Chemical and Biological Technologies in Agriculture

Table 1 The properties of peat and wood biochar as growing media. Adapted and modified from [24]

Properties	Peat	Biochar
Homogeneous quality	Available	Available
Nutrient content/adjustability	Low/adjustable	Low/adjustable
C/N ratio	High	Very high
pH	Low	Mostly medium to high
Permeability^a	Good	Good
Water-holding capacity^a	Medium	High
Balanced water and air capacity^a	Good	Good
Weeds and pathogens	Mainly free	Free
Structural stability and longevity	Medium	Exceptionally high
Reusability	Low, need pre-treatments^b	To be tested, potentially high and requiring pre-treatments
Bulk density	Low	Low
Texture	Uniform	Uniform
Rewettability	Poor	Good
Disease suppressive properties	Neutral	Some evidence^c
Availability (technical)	High	Currently low
Price	Low	Currently very high
GHG emissions	High	Depending on feedstock and production, but carbon neutral
Environmental damages	High	Depending on feedstock and production