Klöffel, Tobias
- Department of Soil and Environment, Swedish University of Agricultural Sciences
Freezing and thawing affect the pore -space structure in agricultural soils with implications for soil hydraulic properties and water flow. Previous studies have focused on the upper few centimeters of the tilled topsoil, where most freeze -thaw (FT) cycles occur, even though deeper soil layers are also subject to freezing and thawing in cold climates. Thus, little is known about how freezing and thawing affect untilled soil layers, which often show high bulk densities that restrict vertical water movement. Furthermore, it remains unclear how shifts in FT patterns with climate change may change the pore -space structure and water flow through these soil layers. Here we investigated the effects of freezing and thawing on X-ray imaged pore -space characteristics, water retention and near -saturated hydraulic conductivity (K) in untilled soil directly below plough depth. Intact cores were sampled at two sites in central Sweden under the same long-term reduced tillage management. The two soils, a silt loam and a silty clay loam, were subjected to three FT scenarios in a laboratory environment intended to represent FT patterns that are considered likely under current and future winter conditions for this region. The latter scenario was characterised by more FT cycles and a lower freezing temperature. Freezing and thawing increased K in the near -saturated range in both soils, which we attribute to observed small (
Temperate -boreal zone; Water retention curve; Hydraulic conductivity; Climate change; Sweden; Ultuna
Soil and Tillage Research
2024, volume: 239, article number: 106041
Publisher: ELSEVIER
Soil Science
https://res.slu.se/id/publ/129366