Inoculation of local lignocellulosic materials for the production of sustainable growing media

General introduction

The goal of this project is to produce a disease and/or pest suppressive peat replacement based on locally produced plant fibers. Peat is still the main resource used for the production of potting soil. Researchers now better understand the importance of soil and substrate biology for crop cultivation, including the role of beneficial micro-organisms. Peat does not seem be a good medium for harboring micro-organisms. Further, because peatlands are unique habitats for protected fauna and flora, exploitation of these areas is being criticized in Europe. Locally produced plant fibers can become a more sustainable alternative to peat. The aim of this project is to create added value to these alternative growth media by adding biological control fungi to add disease- and/or pest-suppressive properties.

Research approach

First, three types of plant fibers (flax shives, reed straw, miscanthus straw) are pre-treated to enable their successful inoculation with biological control fungi. Using specific analyses, we determine the effect of the pre-treatment on the biochemical and physical properties of the fibers. An important aspect is how pre-treatment affects the N-immobilization of the plant fibers. The plant fibers are then inoculated with biological control fungi to study the interaction between the survival of the inoculated fungi and the materials often used in growth media. Finally, plant trials are done with diseases and pest inoculation under controlled conditions to test the performance of these new, possibly disease-suppressive, sustainable growth media.

Relevance/Valorisation

In this project we develop alternatives for peat – a fossil resource – in growth media. Not only does this reduce the demand for peat, it closes resource loops because renewable plant fibers (flax fibers, reed straw and miscanthus straw) are used. Successful inoculation of biological control fungi in growing media will significantly optimize crop cultivation, requiring fewer pesticide applications. This in turn will improve the water quality (no leaching or pesticide drift) as well as human health (fewer pesticide residues on food).