Evaluation of soil physical properties of peat substrate

Abstract

Peat substrate is the main substrate for plant production, mainly for the cultivation of vegetable seedlings and ornamental plants. Peat has good water retention properties, low mass, low pH and is free from diseases and pests. The water retention properties are particularly important for optimizing irrigation and thus water consumption in plant production. We investigated the water retention properties of unused and used peat substrate and various mixtures with additives, as well as the occurrence of water repellency, as this influences water absorption into the substrate. Unused peat substrate and different mixtures retained between 3.4 % and 18.4 % more water than the used substrate. The daily water losses are lower for the used substrates that initially contain lower water content at full saturation. At tensions between 10 and 33 kPa, the unused peat substrate contained between 25 % and 32 % water. The wilting point (WP) for unused peat substrate (tension between 300 and 1500 kPa) was between 15 and 18 %. Peat substrate has a wide interval of field capacity and the transition from the field capacity to wilting point is fast (change in water content between 7 % and 10 %). After drying, the water repellency of both unused and used peat substrates increased.