The Role of Growth Substrates, including Horticultural Peat, in Modern Food Production, and Possible Alternatives
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Senior Research Fellow, Institute of Ecology, Tallinn University
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Associate Professor, Institute of Ecology and Earth Sciences, University of Tartu
The peat that is extracted in Estonia is currently mainly used in the horticultural sector (~96% of the production is horticultural peat with different degrees of processing), and more than 90% of it is exported.
The majority of peat products are exported for plant cultivation to gardens in Western and Southern Europe. Through supporting the plant growth, substrates have a crucial role in ensuring food security.
Regarding export, the question arises whether the calculation of greenhouse gas emissions associated with the use of the substrate should be accounted for the producer or the consumer. It is also necessary to assess more accurately the actual greenhouse gas flows associated with the use of substrate.
In 2022–2024, a study is being conducted in Estonia to clarify why, how, and how much horticultural peat is used in Estonia and what the properties of this peat are, what the carbon dynamics of peat substrates during their use are and what the best alternatives for further use of used horticultural peat are.
The preliminary results of the study show that a significant part of the carbon found in substrate can still be stored in the soil as humus for a long time, and substrate is used as a soil improver within the context of subsequent use. In the Estonian horticulture sector, this practice is widespread and provides a basis for changing the current methodology for calculating greenhouse gas emissions from the substrate.