Research project RE-PEAT – Reuse of growing media for a circular horticulture

General introduction

How can we successfully reuse substrates derived from strawberry (mainly peat), vegetables (perlite), but also from ornamental crops (coir and peat substrates)? And how can we increase the adption in practice of these possible recycling loops? These are the main questions of the RE-PEAT project. Spent substrates after cultivation of cut flowers, strawberries and greenhouse vegetables are often regarded as useless leftovers. However, there are advantages to upgrading such a substantial residual flow through reuse. Every cubic meter of reused peat results in a reduction of CO2 emissions, thus reducing the impact on the climate. If captured and reused, the nutrients left in the substrate can also pay off within the circular economy.

Research approach

In an operational group together with the horticultural sector the available residual flows from farms and greenhouses were inventoried. Near InfraRed Spectroscopy was used for fast and inexpensive characterization. We optimized the quality of the culled substrates. We formulated answers to technical and economic questions. We clarified the reuse regulations. The professional farmers' and growers' organizations participated in this project to highlight the legislative issues.

Relevance/Valorization

Interest in the circular use of cultivation substrates is growing in both the strawberry and ornamental sectors. Peat-based substrates are widely used in horticulture, but this use is under strong pressure, due to export and supply security and increased price volatility. Alternatives such as coir, wood fiber, compost, management residues, etc. are being sought. Complete replacement of peat is not yet on the table due to the lack of sufficient alternatives but the sector is proceeding towards a higher degree of peat replacement.

Financing

Vlaamse Overheid Departement L&V