Biochar made from green waste as peat substitute in growth media for Calathea rotundifola cv. Fasciata

This study examined the feasibility of using biochar substrate made from green waste in place of some or all of the original peat substrate (OP) commonly used for the cultivation of the ornamental plant Calathea rotundifola cv. Fasciata. The three growing media were OP (100%), BGW (100%), and OP + BGW (50% each). BGW reduced media degradation; at the end of the 6-month experiment, the fraction of particles >1 mm was decreased by 39%, 9%, and 21% in OP, BGW, and OP + BGW, respectively. Plant growth was greatest with OP + BGW; total biomass, for example, increased by 22% in OP + BGW relative to peat alone. The results indicate that, in addition to reducing green waste, biochar generates a product that can be used as a partial substitute for peat in the cultivation of C. rotundifola cv. Fasciata. The addition of BGW products to plant growth media may reduce the rate at which the media decomposes and therefore increase media longevity.

► A new method for the production of biochar (low-grade pyrolysis, 160–220 °C maintained for 20 min) is described.
► Biochar generates a product that can partially substitute for peat in the cultivation of C. rotundifola cv. Fasciata.
► The addition of biochar products to plant growth media may reduce the rate at which the media decomposes.