Elucidating the microbiome of the sustainable peat replacers composts and nature management residues.

Sustainable peat alternatives, such as composts and management residues, are considered to have beneficial microbiological characteristics compared to peat-based substrates. Studies comparing microbiological characteristics of these three types of biomass are, however, lacking. This study examined if and how microbiological characteristics of subtypes of composts and management residues differ from peat-based substrates, and how feedstock and (bio)chemical characteristics drive these characteristics.

Understanding the Shift in the Microbiome of Composts That Are Optimized for a Better Fit-for-Purpose in Growing Media.

Three characteristics are considered key for optimal use of composts in growing media: maturity, pH and organic matter content. Maturation is a critical step in the processing of composts contributing to compost quality. Blending of composts with chopped heath biomass, sieving out the larger fraction of composts and acidification of composts by adding elemental sulfur may be used either to increase organic matter content or to reduce pH for a better fit in growing media.

Acidification of composts versus woody management residues: Optimizing biological and chemical characteristics for a better fit in growing media.

Previous research has demonstrated that composts (COM) and woody residues from nature management (MR) are potential peat replacers for growing media, but their compositions are highly variable. Our goal is to make growing media more sustainable by optimizing the selection of local and sustainable alternatives for peat. Different batches of COM and MR were incubated to assess the microbial activity based on (1) the N drawdown risk, (2) the C mineralization and (3) the inoculation efficiency of a commercially available biocontrol fungus.