Peat extraction is associated with significant emissions of greenhouse gases. Using peat substitutes instead of peat can significantly reduce the carbon footprint of growing media production.
HORTICERT has developed a uniform methodology for calculating the carbon footprint, which allows for statements on the greenhouse gas savings of peat-free and peat-reduced potting soils and growing media compared to conventional products with a high peat content. This also creates transparency in the market.
Calculation of the Carbon Footprint
The calculation covers the entire production chain, from the production of raw materials to further processing into substrate components to the production of the final potting soil or growing medium. Emissions from transport, use and disposal are also taken into account.
Raw Material Production
The raw materials for peat substitutes are produced in different ways. Accordingly, the main causes of emissions differ depending on the raw material.
On coconut plantations, for example, emissions are caused in particular by the use of fertilizers. In the case of wood extraction, fuels for forestry machinery, among other things, must be taken into account. Green cuttings are used as a raw material for green waste compost, to which as waste no emissions are attributed.
In the further processing of raw materials into substrate components, emissions from the electricity consumption of production machines as well as from fuel consumption of loaders must be considered. Furthermore, for some materials, such as green waste compost and bark humus, emissions from the composting process play an important role.
Raw materials often go through several process steps before they can be used as a component in a substrate. In the greenhouse gas calculation, the emissions of all process steps must be taken into account.
For substrate production in the growing media plant, the energy required for mixing the potting soils and substrates, as well as fuel consumption by wheel loaders, is particularly important for the calculation of the emissions. In addition, emissions from packaging materials must be taken into account.
Use and Post-Use Phase of the Substrates
Use and disposal must also be included in the calculation of the carbon footprint in order to obtain a complete picture of all the emissions caused by a substrate. Here, further emissions occur due to decomposition processes of organic materials. In the case of the peat, these decomposition processes lead to particularly high emissions due to the carbon that is bound in the peat.
To determine the total carbon footprint of the substrate, the emissions of the different production steps along the supply chain as well as use and disposal are added up. In addition, transport emissions along the entire supply chain are included.