The horticultural sector is gradually reducing the use of peat for the production of potting soils. Alternative materials will be required as a replacement. Biochar has a lot of potential, but is still barely used in greenhouse horticulture. This is partially because biochar suppliers and potting soil companies still do not know each other well enough. Therefore, Wageningen University & Research BU Greenhouse Horticulture is working on joint business cases to bring them together. Researcher Antonella Cristina: "With biochar, potting soil companies can contribute to reducing CO2 emissions."
Biochar is produced from biomass through pyrolysis: the thermochemical conversion of biomass in the absence of oxygen. What remains is a charcoal-like product with a high carbon content: it is a viable alternative to peat. Cristina continues: "Biochar is also very suitable for cultivation due to its favorable characteristics such as porosity and hydrophilic properties"
Despite its benefits, biochar is still rarely used in greenhouse horticulture. This is primarily due to the relatively high cost and small available volumes, the possible fluctuations in metals, dust, and smell.
Collaborating on knowledge development
Firstly, the properties of biochar: it can be made from various types of organic waste such as crop residues, wood, and even nut shells. The composition is closely related to the starting material and can vary, resulting in a range of qualities. Depending on the technical process used, biochar can be contaminated with substances like heavy metals and PAHs. A European Biochar Certificate (EBC) has now been established, which includes guidelines for the production.
Despite the advanced knowledge in research, there is still a lack of trust in practice. To develop trust, it is essential that biochar producers and potting soil companies improve their cooperation so they can collaborate on knowledge development, and product innovation, and even make sure permits mention this relatively new material. Therefore, WUR has submitted a PPS proposal to the Top Sector Horticulture and Starting Materials to bring supply chain parties together. In November 2024, it will be announced whether this proposal has been approved.