Importance of Peat Particle Size Effects on Spatial Root Distribution and Changes on Aeration Properties
Résumé
The evolution of peat hydraulic properties in different parts of containers was studied during root growth. For that, a 4-month long experiment was carried out in a greenhouse in 1L-containers at constant water regime (-1 kPa water potential), with Rosa 'Knock Out'(R) and two different particle-size sphagnum peats, a fine one (0-10 mm) and a coarse one (20-40 mm). Every month, aerial biomass was quantified, whereas root biomass and distribution, water retention, relative gas diffusivity was studied in relation with the depth and the proximity of the container border. The study showed that root growth mainly influenced aeration properties (air filled porosity, relative gas diffusivity), with large differences regarding spatial distribution of roots. But the evolution of aeration properties depended on the peat particle size.