Moisture content of peat-moorsh soils with special attention to periods of drought

Abstract

The paper presents the course of variability of the moisture content of the top layers in shallow (45 cm) and medium-deep (90 cm) peat-moorsh soil profiles in the years 2015–2019 against the background of the same meteorological conditions and a similar level of the groundwater table. The relative precipitation index ( RPI) classifies the years 2015 and 2016 as dry, 2017 as wet, and 2018 and 2019 as average. For periods of atmospheric droughts, the average daily climatic water balance ( CWB) ranged from –5.30 to –1.35 mm∙d –1. The water table did not fall below 90 cm b.g.l. during the entire study period, and the range of its fluctuations was 8 cm greater in the shallow than in the medium-deep profile. The range of moisture at different depths varied significantly and ranged from approx. 6% in periods of drought to about 80% in wet periods. Soil moisture throughout the measurement period was above the plant available water range (p F > 4.2). The occurrence of soil drought in the shallow peat-moorsh soil profile had a range of up to 40 cm, and in the medium-deep profile of up to 30 cm. The sequence of no-precipitation days and the maximum amount of daily evapotranspiration during them determine the possible timing of drought; however, it is the precipitation distribution in individual months, considered in the current CWB values, that ultimately determine the formation of soil water resources at the research site.

Keywords

• climatic water balance
• moorsh
• organic soils
• soil moisture content
• soil water potential