1st International Conference of Soil and Agriculture:
TOWARDS SOIL SUSTAINABILITY
11–13 June 2024 • Lublin–Nałęczów, Poland

https://doi.org/10.24326/ICSA1.PP.26
Published online: 4 October 2024

Critical soil moisture content of the shrinking process
for selected fen peat types
Ryszard Oleszczuk¹*, Ewelina Zając²

¹ Institute of Environmental Engineering, Warsaw University of Life Sciences – SGGW, Nowoursynowska 159,
02-766 Warszawa, Poland
² Department of Land Reclamation and Environmental Development, University of Agriculture in Krakow,
Mickiewicza 24-28, 30-059 Kraków, Poland
* Corresponding author:

Abstract
Peat soils decrease in volume through shrinkage as a result of water loss. This results in the formation of fissures and cracks, which accelerate the processes of mucking and mineralisation of organic matter. The characteristics of this process in drained peat soils differ from its course in heavy mineral soils (clays, loams) and it is relatively well recognised. There is relatively little data in the literature on the critical moisture content of the shrinkage process, i.e. the moisture content beyond which peat does not return to its original volume after re-wetting, and on the value of reversible shrinkage, which is a measure of the ability of peat to swell again due to re-wetting. The aim of this study was to determine critical moisture values during shrinkage-swollenness processes for selected low peat species from the largest peatland complex in Poland, i.e. the Biebrza Marshes. The study presents results of critical moisture of shrinkage and reversible shrinkage for four low peat species, i.e. oleic, reed, sedge and moss peat. The study was carried out using the saran resin method with the measurement technique of soil geometry changes. On the basis of the research carried out, it was found that in the case of alder peats the critical moisture content values of the shrinkage process are in the range of approx. 65–80% vol. and for rush peats the critical moisture content range is 70–90% vol. For sedge peats, the range is very narrow at around 80–86% vol. and for moss peats, the range is the largest at around 55–90% vol. In all the peats studied, the value of reversible shrinkage varied between 30–40%. The above results are important indications for proper water management in peat soils in terms of not allowing them to dry out too intensively.

Keywords: drainage of peatlands, shrinkage, rewetting, swelling

How to cite
Oleszczuk R., Zając E., 2024. Critical soil moisture content of the shrinking process for selected fen peat types. 1st International Conference of Soil and Agriculture: Towards Soil Sustainability. https://doi.org/10.24326/ICSA1.PP.26