Developing new potting mixes with Sphagnum fibers

Abstract

Jobin, P., Caron, J. and Rochefort, L. 2014. Developing new potting mixes with Sphagnum fibers. Can. J. Soil Sci. 94: 585–593. Researchers are developing techniques to mass produce Sphagnum fibers (SF) on a sustainable basis since this material has properties that could benefit the growing-media industry. The objective of this study was to incorporate SF into peat-based substrates to enhance the value of brown Sphagnum peat and/or replace perlite in blond peat mixes. Nine substrates were prepared by mixing brown Sphagnum peat (BrSP) or sieved brown Sphagnum peat (sBrSP) with 0, 15 and 30% of SF and substituting 0, 50 and 100% of the perlite in a 70% blond Sphagnum peat (BSP) and 30% perlite mix with SF. The growth of Pelargonium was unaffected by the addition of SF, with the exception of above-ground biomass which was 15% lower in the BrSP substrate containing 15% SF. In the case of Petunia, above-ground biomass increased with a 30% SF addition to sBrSP, and below-ground biomass increased with a 30% SF addition to BrSP and sBrSP. Adding SF to peat increased water retention and hydraulic conductivity, but either reduced or had no impact on air-filled porosity. Removing fine particles from BrSP and adding 30% SF provided promising results, although the effect varied with plant species. Moreover, it is clear that SF can be used as a substitute for perlite in BSP mixes.

Increasing Sustainability of Growing Media Constituents and Stand-Alone Substrates in Soilless Culture Systems

“…Non-decomposed Sphagnum has been used with great success in the cultivation of orchids as well as together with peat substrates for the cultivation of Tagetes patula L. [150]. These results were confirmed by investigations with Pelargonium and Petunia [151]. Adding Sphagnum fibers to peat increased water retention and hydraulic conductivity, but either reduced or had no impact on air-filled porosity.…”

Physical Properties of Organic Soil: Adapting Mineral Soil Concepts to Horticultural Growing Media and Histosol Characterization

“…The fact that the structure rapidly evolves due to decomposition and reorganization and is very sensitive to disturbance requires running multiple measurements with time (Allaire‐Leung et al, 1999; Jobin et al, 2014). The disturbance issue is then a key factor because of root activity.…”

“…Sphagnum fiber is a valuable resource that has many uses. Indeed, it can be used in the development of new growing media containing a lower percentage of peat while offering similar aeration, structure, and water retention qualities (Jobin et al, 2014). It also appears as a plant material supply for boreal ecosystem restoration efforts, such as after the cessation of peat extraction activities (González and Rochefort, 2014), mine closures in peatland‐dominated areas (Corson and Campbell, 2013), and exploration or petroleum extraction pads within the boreal forest (Sobze et al, 2012).…”

“…During this period of cultivation, the rooting system will also develop, invading pores (Cannavo et al, 2011; Cannavo and Michel, 2013). This can cause a rapid evolution of soil properties (Jobin et al, 2014; Cannavo and Michel, 2013), with a loss (Cannavo et al, 2011), no change (Allaire‐Leung et al, 1999), or an increase in the hydraulic conductivity (Jobin et al, 2014; Cannavo and Michel, 2013) and sometimes an associated increase in total porosity (Jobin et al, 2014).…”

Soil water dynamics and hydrophysical properties of regenerating Sphagnum layers in a cutover peatland

“…More recently, research has also focused on the potential of cutover peatlands as sites for growing Sphagnum biomass in order to produce material for horticultural substrates on a more sustainable basis (Gaudig, 2012;Pouliot et al, 2015;Gaudig and Joosten, 2002). Sphagnum biomass has been found to be a suitable growing media substitute for 'white peat', the slightly decomposed Sphagnum peat currently used by the industry, for certain crops and applications (Emmel, 2008;Jobin et al, 2014).…”