Mechanical Container Filling Alters Texture and Water Retention of Peat Growth Media

in HortTechnology
Author: Juha Heiskanen1
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  • 1 The Finnish Forest Research Institute, Suonenjoki Research Station, FIN-77600, Suonenjoki, Finland

Two commercially produced growth media made of light, low humified sphagnum peat, were used to determine how filling into containers affects the particle size distribution and water retention characteristics of peat. It was shown that the filling procedure used broke up the peat particles, resulting in a significant increase in the proportion of particles < 1 mm (g·g-1). Due to the increased proportion of fine particles, the water retention of the peat media increased under wet conditions (-0.1 kPa matric potential), while the air-filled porosity decreased to nearly 0. Also, at matric potentials lower than -0.1 kPa, the reduction in air-filled porosity may restrict aeration and availability of oxygen to roots, thus reducing growth of plants.