A new publication from Roberts, Paul etal.
Seaweed cultivation is a high growth industry that is primarily targeted at human food and hydrocolloid
markets. However, seaweed biomass also offers a feedstock for the production of nutrient-rich
biochar for
soil amelioration. We provide the first data of biochar yield and characteristics from intensively cultivated
seaweeds (Saccharina, Undaria and Sargassum – brown seaweeds, and Gracilaria, Kappaphycus and
Eucheuma – red seaweeds). While there is some variability in biochar properties as a function of the origin of
seaweed, there are several defining and consistent characteristics of seaweed biochar, in particular a
relatively low C content and surface area but high yield, essential trace elements (N, P and K) and
exchangeable cations (particularly K). The pH of seaweed biochar ranges from neutral (7) to alkaline (11),
allowing for broad-spectrum applications in diverse soil types. We find that seaweed biochar is a unique
material for soil amelioration that is consistently different to biochar derived from ligno-cellulosic
feedstock. Blending of seaweed and ligno-cellulosic biochar could provide a soil ameliorant that combines a
high fixed C content with a mineral-rich substrate to enhance crop productivity.
If this interests you, you can read the whole Paper here:
biochar from seaweed