SOIL SCIENCE ANNUAL 2020, 71(3), 185–193 https://doi.org/10.37501/soilsa/124450 Physical, water and redox properties of vertisols of the Sępopol Plain in north-eastern Poland Mirosław Orzechowski1*, Sławomir Smólczyński1, Barbara Kalisz1 1 University of Warmia and Mazury in Olsztyn, Department of Soil Science and Land Reclamation, Plac Łódzki 3, 10–722 Olsztyn, Poland * Dr hab. inż. M. Orzechowski, [email protected], ORCID iD: https://orcid.org/0000-0002-0041-8525 Abstract Received: 03.03.2020 Vertisols occurring in the Sępopol Plain in north-eastern Poland are characterized by high natural Accepted: 23.06.2020 fertility. They belong to the group of soils with high clay content, which show the ability of periodic Associated editor: C. Kabała shrinking and swelling of clay minerals. As a result of variable moisture conditions, deep cracks and sliding surfaces are formed on the surface of the soil aggregates. The purpose of this research was to determine the chemical, physical, air-water and redox properties of vertisols developed Keywords from glaciolimnic sediments of the Weichselian glaciation, and having textures of clay (C), loam (L) and heavy clay (HC). The studied soils had high fi eld water capacity (pF 2.0) and high content Vertisols of water unavailable to plants (pF 4.2), as well as low volume of air pores. A signifi cant positive Glaciolimnic sediments correlation was found between the amount of clay and the volume of water unavailable to plants Physical properties (pF 4.2), and a negative correlation between the amount of clay and content of water available to Water retention plants (AWC), including water readily available to plants (RAWC). The distribution of soil pores Redox potential was unfavourable, and the ratio of macropores to mesopores to micropores in humic horizons was 1:2.7–5.1:1.5–5.4. The studied vertisols had low values of redox potential (Eh) and oxygen diffusion rate (ODR). The values of the Eh were above 300 mV, a threshold value for oxidised and reduced soil, only in surface horizons. 1. Introduction and Kabała, 2014; Kabala et al., 2015; Dudek et al., 2019), near Ciechanów (Olszewski, 1956) and in the northern part of the Vertisols were separated as a new taxonomic unit in the country above 54° N – in the Sępopol Plain (Uggla and Witek, fifth (Polish Soil Classification 2011) and the sixth (Kabała et 1956; Długosz et al., 2009; Orzechowski et al., 2018) and around al., 2019) edition of Polish Soil Systematics (SGP6). In the SGP6 Gniew in the Starogard Lakeland (Prusinkiewicz, 2001; Mocek they were classified into the type of vertisols in the order of et al., 2009). swelling soils. These soils contain ≥ 30% of clay fraction and The origin of vertisols in Sępopol Plain is associated with have a wertik horizon of thickness of ≥ 25 cm. Vertisols have the deglaciation of ice-dammed lakes of Pomeranian phase of fusiform or lenticular structural aggregates and/or sliding Weichselian glaciation and accumulation of glaciolimnic de- surfaces (slickensides) in ≥ 10% of the soil volume. Vertisols posits (Körnke, 1930; Roszko, 1968). These deposits were par- are soils which origin is closely related to the lithology and ent materials for black earths and vertisols of specific chemi- mineralogical composition of the parent material. As a result cal, physical and hydraulic properties (Uggla and Witek, 1958; of swelling and shrinking of soil rich in clay minerals, deep Orzechowski et al., 2018). The mentioned soils are compacted cracks are formed (Kovda and Wilding, 2004; Łabaz and with low infiltration coefficient, frequently under gleyic condi- Kabała, 2014; IUSS Working Group WRB, 2015; Kabała et al., tions, which suggest reducing conditions in soils. In the past, 2019, Miller et al., 2010). Due to their high natural fertility, due to the „heavy“ granulometric composition, these soils were vertisols are an important soil group widespread in countries used as permanent grasslands. The use of these soils for grazing such as Australia, China, India, (Wilding, 2004) USA (Miller et with average annual precipitation in the range of 580–600 mm al., 2010), Senegal, Romania, Turkey, Bulgaria, Hungary, Serbia and average annual air temperature of 7.2°C was beneficial and southern Spain (Ahmad, 1996; Favre et al., 1997; DeCarlo for the development of grass vegetation and accumulation of and Caylor, 2019). On the Earth’s surface, the majority of ver- soil humus (Uggla and Witek, 1958; Suchecki, 2010). Currently, tisols occur in the equatorial and subtropical zone. In Poland, vertisols are cultivated and winter wheat, winter oilseed rape, vertisols occur in the southwestern part, near Wrocław (Łabaz sugar beet and maize are grown on these soils. © 2020 by the authors. Licensee Soil Science Society of Poland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY NC ND 4.0) license (https://creativecommons.org/licenses/by-nc-nd/4.0/). 185 Orzechowski et al. SOIL SCIENCE ANNUAL The purpose of this research was to determine the chemi- ric method. The content of organic carbon (TOC) and total nitro- cal, physical, air-water and redox properties of vertisols devel- gen (TN) was analysed using a CN Vario Max Cube Elementar oped from fine-grained glaciolimnic sediments in young glacial analyser, the content of exchangeable base cations (Ca2+, Mg2+, landscape of north-eastern Poland. K+, Na+) was determined in the extract of ammonium acetate (1 mol dm–3) at the pH of 7.0. Ca2+, Mg2+, K+ and Na+ were deter- mined using iCAP 7400 ICP-OES Termo Scientific spectrometer. 2. Materials and methods Hydrolytic acidity (HA) was determined by the method of Kap- –3 pen after extraction in 1 mol dm CH3COONH4 (Van Reeuwijk, The research was carried out in the Sępopol Plain and 2002). The cation exchange capacity (CEC) was calculated as the northern parts of the Masurian Lakeland – the areas of ice- sum of total exchange bases (TEB) and HA. dammed lakes origin of the Weichselian glaciation (Vistula) of Particle density (Sd) was determined by pycnometric method the Pomeranian phase (Fig. 1). At five sites of ice-dammed lakes and soil bulk density (Bd) in undisturbed 100 cm3 soil samples tak- origin, with different size, relief, hypsometry and soil cover, five en at four replications, steel cylinders. Total porosity (Tp) was cal- soil profiles were studied: near Reszel – Black vertisols (SGP6) – culated according to the equation: Tp = (Sd – Bd) × Sd –1 × 100 (%). Pellic Vertisol (Aric, Mollic, Hypereutric, Grumic, Endostagnic) Soil water retention properties were determined using low- – WRB 2015, (054°02′53.90 N 021°05′31.93 E, located at 94.5 m pressure (in pF range 0–2.7) and high-pressure (in pF range 3.0– a.s.l.) and Typical vertisols – Haplic Vertisol (Aric, Grumic, Hy- 4.2) chambers. Water capacities (Wv/v) were examined at water pereutric), (054°02′20.71 N 021°20′03.16 E, 88.0 m a.s.l.), near potential of 98.1 hPa (pF 2.0), 981.0 hPa (pF 3.0) and 15 547.9 Kętrzyn – Gleyic vertisols – Haplic Vertisol (Mollic, Hypereu- hPa (pF 4.2). The volume of the following soil pores and water tric, Gleyic) (054°02′28.80 N 021°20′34.32 E, 94.5 m a.s.l.), near capacities were calculated: macropores (total porosity-Wv/v at Sępopol – Typical vertisols – Haplic Vertisol (Aric, Hypereutric, pF 2.0), micropores (Wv/v at pF 4.2), mesopores (Wv/v at pF 2.0 – Mazic), (054°18′03.89 N 021°05′43.58 E, 41.5 m a.s.l.), and near Wv/v at pF 4.2). Mesopores are related to potential useful water Lidzbark Warmiński – Typical vertisols – Haplic Vertisol (Aric, retention because they contain water available to plants (AWC Hypereutric, Grumic), (054°09′54.19 N 020°32′31.73 E, 90.0 m – available water capacity). Among AWC, readily available wa- a.s.l.). Black and typical vertisols were under crop cultivation ter capacity – RAWC (Wv/v at pF 2.0 – Wv/v at pF 3.0), and small while gleyic vertisols were under permanent grasslands. The pores available water capacity – SAWC (Wv/v at pF 3.0 – Wv/v at studied vertisols do not occur in large soil complexes, but in pF 4.2) were calculated (Zawadzki, 1973, Walczak et al., 2002). various geomorphological structures forming a mosaic with Redox potential (Eh) and oxygen diffusion rate (ODR) were de- other soil types (black earths, lessive soils and brown soils). termined with a REDOX apparatus for measuring potential and In collected soil samples, using standard methods for min- diffusion rate in soil Institute of Agrophysics, Polish Academy of eral soil studies, the following soil properties were determined: Sciences in Lublin (Stępniewska 1988) and reduction rate assess- soil texture by Bouyoucos-Cassagrande method modified by ment index (rH) was calculated according to the formula: –3 –1 Prószynski, pH in H2O and in 1 mol dm KCl by the potentiomet- rH = (Eh × 29 ) + 2 × pH Fig. 1. Location of studied soil sites 186 SOIL SCIENCE ANNUAL Physical, water and redox properties of vertisols Coefficient of linear extensibility (COLE) was calculated at which in humic horizons ranged from 16.0 g kg–1 to 58.0 g kg–1. the soil sample moisture content corresponding to a pressure The TN content was between 1.81 g kg–1 and 3.87 g kg–1. Gleyic of 33 kPa. vertisols, which were under permanent grasslands, had the highest contents of TOC and TN. The C/N ratio ranged from 7.3 to 15.0. Vertisols also had high CEC, above 23.81 cmol (+) kg–1, 3.