A1 Horizon Research Articles

Tectono-sedimentary processes shaping the West Sardinian margin and adjacent oceanic basin during the Plio-Quaternary (Western Mediterranean Sea)

A seismic analysis of the Plio-Quaternary stratigraphy of the West Sardinian continental margin and adjacent oceanic basin was conducted using single- and multi-channel seismic profiles. Two main chronostratigraphic boundaries have been used: i) the Ms. horizon, marking the base of the Pliocene and corresponding to the top of the Messinian evaporites on the lower continental slope and deep basin, and the Messinian erosional truncation on the upper slope and shelf; and ii) the newly identified A0 horizon, marking the base of the Quaternary (2.6 Ma). This study reveals key geological features affecting the Pliocene and Quaternary deposits: a) salt tectonic structures, b) normal faults, c) volcanic structures, d) pockmarks, e) canyon systems, and f) regressive clinoform system. These features are linked to tectono-sedimentary processes such as vertical movements, magmatic activity, halokinesis and sediment dynamics. Vertical movements are associated with the thermal subsidence of the Oligo-Miocene basin opening, water and sediment loading/unloading during and after the Messinian Salinity Crisis, and Pleistocene uplift onshore. These movements resulted in the tilting of the margin, which influenced normal faulting through reactivation of Oligo-Miocene faults, and the Plio-Quaternary depositional patterns. Several normal faults acted as conduits for lower Pliocene magmatic activity and gas migration, forming volcanoes and pockmarks on the continental shelf and upper slope. Salt tectonics in the lower slope and deep basin produced diapirs and rollover structures, significantly impacting the thickness and distribution of Pliocene and, to a lesser extent, Quaternary deposits. Canyons system formation seems to be controlled by the interplay of the Quaternary sea-level fluctuations with the margin's ongoing tilting. Similarly, the regressive clinoform system also results from these two factors, but is further influenced by erosion of uplifted Sardinian onshore areas.

Soil cover structure and transformation of morphometric parameters of Haplic Chernozems under no-tillage

The results of the field experiment have been analyzed, it was set up on two experimental fields (with an area of 2.4 hectares each), where two different agricultural techniques – traditional and no-till – were applied. Diagnostics of morphometric parameters of typical chernozems such as: the thickness of the A1 horizon, A1 + AB horizons and the depth of carbonates reaction with 10% HCl, has shown that some changes in soils and soil cover had occurred in the fields over 8 years. The integral indicator of soil productivity is the thickness of the humus horizon, it demonstrated trends to decrease and increase in the soil cover structure of the experimental fields with different compositions of chernozem subtypes. The trends result from both climate change and periodic dry periods, which are not typical of the region, and from the change of traditional technology to no-till. The carbonates leaching from chernozem profiles in all variants of the experiment decreased, which correlates well with climatic indicators, changing with the seasons of the year. Chernozems with thin humus layaer and reacting with HCl close to the surface do not require liming. The revealed changes are not statistically significant, they reflect the resistance of chernozems to the variability of natural and anthropogenic factors of soil formation. Crop residues on the soil surface under no-tillage reduce physical evaporation, which contributes to moisture accumulation in the soil. The use of cover crops in winter also increases the moisture reserves, which are consumed by the plants during the summer growing season. Information on the transformation of morphometric parameters allows making temporal and spatial corrections in the applied agricultural practices (crop rotation, fertilization, the use of cover crops, herbicides and pesticides).

ОЦЕНКА САДОПРИГОДНОСТИ ДЕРНОВО-ПОДЗОЛИСТЫХ ПОЧВ НА КРЕМНИСТЫХ ПОРОДАХ ЮГО-ЗАПАДА КАЛУЖСКОЙ ОБЛАСТИ

The data of the survey of sod-podzolic soils under industrial gardens on the weathering crust of trepels and flanks and on water-glacial deposits underlain by siliceous rocks are presented. The main reason for the op-pression and death of trees is a sharply acidic reaction deeper than 50 cm (pHKCl < 3.9), the exchange Al content is above the toxicity threshold (>0.9 mmol /100g of soil). Soils on homogeneous sediments are characterized by a density of 0.6-0.8 g / cm3, an active moisture range of 25-30%, an average content of exchangeable Ca and Mg, soils on binomial deposits – a density of 0.9-1.3 g / cm3, an active moisture range of 5-15%, a low content of exchangeable Ca and Mg. Before laying perennial plantings, it is neces-sary to introduce dolomite flour with a high Mg content into planting pits, the approximate dose is 15-25 t / ha. In gardens on homogeneous rocks, moisture–charging irrigation is possible, on binomial deposits, drip irrigation or fertigation is better. Sod-podzolic soils on homogeneous sediments are diagnosed by a power-ful 50-70 cm A2 horizon. In the profile of soils on binomial deposits under the A2 horizon with a thick-ness of 25-30 cm, the Bf horizon of ochre color is formed.

Spatial heterogeneity of the content and reserves of humus of virgin light gray forest soils of the south of the Tyumen region

The results of the analysis of the state of humus in virgin light gray forest soils in the south of the Tyumen region are presented. A total of 96 full profile sections were made and described, soil samples were taken for laboratory studies. The results were processed in MS Excel using the Descriptive Statistics tool. It was revealed that the subtype of light gray forest soils has a low content of humus in the upper part of the profile - 2.07±0.47 %. A sharp decrease in the humus content down the profile was established. In the A1A2 horizon, the average humus content in the sample is 1.09 % with fluctuations from 0.61 to 1.65 %. Humus formation in the studied soils is of an accumulative nature, since soils with an above-average humus content predominate in the analyzed sample. The content of total nitrogen in horizon A1 is 0.11±0.03 % at a carbon to nitrogen ratio of 11.2±1.0. Down the profile, the content of total nitrogen sharply decreases, which is associated with the leaching of water-soluble nitrogen compounds. On average, humus reserves in the A1 horizon are 38±11.7 t/ha, which is half of the reserves in the 0-100 cm layer. When light gray forest soils are involved in arable land, the nutrient regime of agricultural crops will be formed exclusively due to the A1 horizon.

Сезонная динамика влажности и плотности дерново-подзолистых почв на склоновой катене ЛОД РГАУ-МСХА им. К.А. Тимирязева при различных уровнях рекреационной нагрузки

The seasonal dynamics of soil moisture, bulk density and moisture reserve in the topsoil of Podzoluvisol representative variants at the Forest Experimental Station of the RSAU-MTAA at various levels of recreational load is investigated. The assessment of the influence of recreational load on the surface horizons (A1, A1A2, A2) of Podzoluvisols within the slope catena (the summit of the moraine hill – the middle part of the slope – the lower part of the slope) is given. Three levels of recreational load are considered: minimal (background), medium and strong. The analysis of soil moisture was carried out by the thermal weight method, one of the bulk density – according to N.A. Kachinsky method, using 100 cm3 mortise cylinders – in triple repetition. The results were statistically processed using ANOVA in accordance with the GLM (IBM SPSS) version 25 procedure. The conducted research revealed a pronounced seasonal dynamic of the studied properties of Podzoluvisols with a clear differentiation according to their position in the catena and the level of recreational load. Summer soil moisture values of the surface A1 horizons can be 2.5 times lower than spring ones. Soil moisture at the slope foot is 1.1–1.5 times higher than at the summit of the moraine hill. The main consequence of the recreational load increasing is a significant rise in the bulk density of the topsoil horizons A1 – A2, maximally expressed in conditions of increased soil moisture in the lower part of the catena. Moisture reserves in the topsoil significantly decrease with an increase in recreational load and the associated soil bulk density. The soil bulk density is higher in summer than in spring and early autumn. The established dependences of seasonal dynamics of soil moisture, bulk density and moisture reserve in the topsoil on the slope steepness and recreational load will be useful for planning and environmentally safe regulation of spatially differentiated recreational load in different parts of the urban slope landscape, even in case of a slight slope steepness (up to 3-4 °) and of the presence of vegetation cover close to natural conditions. Keywords: RECREATIONAL LOAD, ECOLOGY OF FOREST SOILS, HETEROGENEITY OF FOREST SOILS, SEASONAL DYNAMICS OF SOILS, SOIL MOISTURE, SOIL BULK DENSITY, PODZOLUVISOLS, CATENA

Chemical, physical‐temporal and spatial changes in 25‐year‐old mine soils in Southeast Ohio

AbstractReclaimed surface coal mines afford an opportunity to study initial pedogenic processes. This study sought to determine pedogenic processes active in a topsoiled* surface mine over 25 years. Soils were taken at 108 points from three grids in 1979 (1 year) and 2004 (25 years post‐reclamation) across a 20 ha watershed. The upper darkened portion of the replaced soil (^A1, ca. 0–5 cm), lower portion of the replaced soil (^A2, ca. 5–15 cm), and spoil (^2C) were sampled. Exchangeable Ca2+ increased from 4.3 cmolc kg−1 in 1979 to 8.2 cmolc kg−1 in 2004, and exchangeable Mg2+ increased from 2.5 to 3.3 cmolc kg−1. Soil organic carbon (SOC) increased from 0.59% to 4.05% providing evidence for humification and cycling of basic cations. SOC increases and structural development decreased bulk densities from 1.70 to 0.99 g cm−3 in the ^A1 and 1.70 to 1.24 g cm−3 in the ^A2. pH decreased in all horizons. In ^2C horizons, total sulfur decreased from 0.39% to 0.13% and electrical conductivity 3.34 dS m−1 to 1.01 dS m−1, indicating probable pyrite oxidation and salt leaching. Soils classified as Anthroportic/Anthrodensic Udorthents, as three representative pedons lacked cambic horizons. Mine soil variograms indicated higher spatial dependency in ^A1 and ^A2 horizons in 2004 than 1979 (decreasing nugget: sill ratios), whereas ^2C horizons had lower spatial dependencies in 2004. This suggests that surface horizons are more influenced by soil forming factors than spoil, which is more influenced by 'random' conditions of reclamation and not in equilibrium.

Reservoir Distribution Analysis with Seismic Colored Inversion in Fluvial Deposition Environment West Natuna Basin

West Natuna Basin is a fluvial deposition environment with thin-bed sand reservoir overlapping with shale and shaly sand. Inversion is applied using Seismic Colored Inversion which considered to provide with robust result to identify geological features such as sand channels’ continuity with low-acoustic impedance value alongside zone of interest. Seismic Colored Inversion can be made by inverting seismic data into Acoustic Impedance value which can be obtained by deriving data from well, as control, then utilized it to change the seismic data volume to Acoustic Impedance volume. By performing a lateral slicing along the target horizons, the distribution of sand channels can be identified. Therefore, the promising reservoir zone with low Acoustic Impedance value and the non-reservoir zone can be clearly distinguished. Slicing was performed in A1 horizon, showing low AI sand channels ranging from 12.000 up to 15.500 ((ft/s)*(g/cc)) spreading at the center of the map through the East. Slicing in B2 horizon, showing what appears to be sand channels with low AI value ranging from 16.000 up to 17.800 ((ft/s)*(g/cc)) spreading at the center of the map between the U1 and U3 well, and appears at the Northeast of the map.

National-scale spectroscopic assessment of soil organic carbon in forests of the Czech Republic

Soil Carbon (C) is central to the functioning of ecosystems and climate change mitigation. It represents the largest terrestrial pool and much of it, is stored in forest soils. Soil Organic Carbon (SOC) in a forest varies not only laterally, but also vertically (i.e., with depth). However, the SOC content of forest soil horizons has not been investigated over large scales, despite its importance for framing our understanding of soil function. Visible–Near Infrared (vis–NIR) reflectance spectroscopy enables rapid and cost-effective examination of forest SOC distribution, both laterally and vertically. This study aims to evaluate the potential of vis–NIR spectroscopy for classifying and predicting the SOC concentration of organic and mineral horizons in forests of the Czech Republic. We investigated 1080 forest sites across the country, each with five soil horizons, representing the Litter (L), Fragmented (F), and Humus (H) organic horizons, as well as the A1 (depth of 2–10 cm) and A2 (depth of 10–40 cm) mineral horizons. We, then, used Support Vector Machines (SVMs) to classify the soil horizons based on their spectra and also to model the SOC concentration of (i) the profile (organic and mineral horizons together), (ii) only the organic horizons, (iii) only the mineral horizons, and (iv) each individual horizon separately. The models were validated using 10-repeated 10-fold cross-validation. Results show that the SVM with radial basis kernel could accurately classify the soil horizons (Correct Classification Rate (CCR) of 70% and Kappa coefficient of 0.63). The SOC model developed for the soil profile performed well (R2 = 0.76 and RMSE = 1.63%). The model of the combined organic horizons was considerably more accurate than that of the combined mineral horizons (R2 = 0.78 and R2 = 0.53, respectively). Estimates of SOC in the individual soil horizons had R2 values greater than 0.63 but those of the F and A1 models were better with R2 > 0.70. The study indicates that vis–NIR spectroscopy can effectively characterize the SOC concentration of the highly variable forest soil horizons in the Czech Republic.

Rectorite as a Syngenetic Component of a Soddy-Podzolic Soil

Rectorite (allevardite) is a regularly interstratified mica–smectite, in which each mica (A) layer is “sandwiched” between smectite (B) layers creating ABABAB…. sequence with 50% contribution of each layer. Similar to other ordered minerals, rectorite is rare in nature. The paper provides the results of the study on properties and mineral composition of the soddy weakly podzolic soil (Umbric Albeluvisol) in the Komi Republic, Russian Federation. Rectorite is found in fine fractions of A1 and A2 horizons of this soil. The studied soil has been formed on the light-textured parent material. The soil profile is texturally differentiated by the eluvial type. In the mineral horizons, $${\text{p}}{{{\text{H}}}_{{{{{\text{H}}}_{2}}{\text{O}}}}}$$ varies within 5.1–5.3. The mineral composition of fractions <2, 2.0-0.5 and <0.5 μm was studied by X-ray diffractometry (XRD). In the parent material, smectite predominates and is represented by the high-charged beidellite. In addition, its clay fraction contains mica, vermiculite, kaolinite and chlorite, as well as fine quartz. Vermiculite structure is chloritized. The mineral composition of the clay fraction undergoes transformation within the upper 40 cm of the profile, which is maximally pronounced in the upper 20 cm. The content of smectite is lower there; and that of fine quartz is higher, fine fractions additionally contain rectorite. This mineral is identified on the base of the integer (00h) reflection series 24.54 and 12.27 A for air-dry samples. After saturation with ethylene glycol, the (001) peak shifts to 26.77 A. Calcination during 2 h at 550°C results in shifting of this peak to 10 A. Rectorite is believed to be a syngenetic component of this soils and is formed at the early stage of smectite transformation into illite, being a transitional product of this transformation.

Quantitative Analysis of Pore Space Structure in Dry and Wet Soil by Integral Geometry Methods

We present a methodology for a numerical analysis of three-dimensional tomographic images in this paper. The methodology is based on integral geometry, topology, and morphological analysis methods. It involves calculating cumulative and non-cumulative pore size distributions of Minkowski functionals and Betti numbers. We investigated 13 samples in dry and wet (saturated beyond the field capacity) conditions within different horizons of the Phaeozem albic. For samples of the arable horizon, an increase in the Euler characteristic was observed in the process of wetting. For samples from the A2, AB and B2 horizons, the Euler-Poincare characteristic decreased during wetting. It has been proven that both Betti numbers (number of isolated pores and number of “tunnels”) decrease with swelling of the AB and B2 horizons at a depth of 20–90 cm. For samples from the arable horizon, another dependence was observed: A Betti number of zero increased first but decreased during wetting. Based on the change in topological characteristics, two methods of changing the topology of the void space of the soil were demonstrated. The above-described quantitative changes of proposed parameters of pore space tomographic images prove the possibility and progressiveness of their usage for the pore space transformation estimate.

Soil energy potential in the coniferous and broadleaf forests of Holosiivskyi National Nature Park

The article presents the results of three-year studies of the energy reserve of soils of pine and oak forests of the Holosiivskyi National Nature Park. Soils largely reflect the state of many internal processes in forest ecosystems. The most important for the ecosystem sustainability is the soil content of organic matter, which determines the energy potential of the soil, and its fertility. The aim of the study was to investigate the energy reserve gradient in depth in oak and pine forests by organic matter content, to compare the effect of two different types of forest phytocenoses on soil energy potential as an important indicator of ecosystem stability. Soil profiles were investigated, in which 7 horizons of soil were isolated in the oak forest, and only 4 were clearly identified in the pine forest. Tests for carbonates and clay loam showed sod-podzolic gley soil in an oak forest and sod-hidden podzolic soil in pine forest with poorly expressed soil horizons. Soil energy potential was determined The soil energy gradient in soils is distributed with a decrease from the upper horizon to the lower in both oak and pine forests. The upper humus horizon in the pine forest was richer in organic matter than the humus horizon in the oak forest. At the same time, in the pine forest soils the sharpest decrease of organic matter with depth was observed. The deciduous forest phytocenoses provided a larger and more uniformly distributed organic matter stock in the soil horizons. Comparing the energy reserve of broadleaf and coniferous forest phytocenoses soils, differences in the soil horizons, which amounted to 189506.9 kJ/m3 between humus A1 horizons in both forests, were 24 %. The difference between the eluvial horizons was 32216.2 kJ/m3 – 9 %, the difference between the eluvial horizons – 23747.1 kJ/m3 – 8 %, and the difference between the soil-forming horizons of 3018.7 kJ/m3 – 1.6 %. The study confirmed the importance of determining the energy potential of soils to assess the stability of phytocenoses.Manuscript received 21.04.2020

Distinct fungal successional trajectories following wildfire between soil horizons in a cold-temperate forest.

Soil fungi represent a major component of below-ground biodiversity that determines the succession and recovery of forests after disturbance. However, their successional trajectories and driving mechanisms following wildfire remain unclear. We examined fungal biomass, richness, composition and enzymes across three soil horizons (Oe, A1 and A2) along a near-complete fire chronosequence (1, 2, 8, 14, 30, 49 andc.260yr) in cold-temperate forests of the Great Khingan Mountains, China. The importance of soil properties, spatial distance and tree composition were also tested. Ectomycorrhizal fungal richness and β-glucosidase activity were strongly reduced by burning and significantly increased with 'time since fire' in the Oe horizon but not in the mineral horizons. Time since fire and soil C:N ratio were the primary drivers of fungal composition in the Oe and A1/A2 horizons, respectively. Ectomycorrhizal fungal composition was remarkably sensitive to fire history in the Oe horizon, while saprotroph community was strongly affected by time since fire in the deeper soil horizon and this effect emerged 18 years after fire in the A2 horizon. Our study demonstrates pronounced horizon-dependent successional trajectories following wildfire and indicates interactive effects of time since fire, soil stoichiometry and spatial distance in the reassembly of below-ground fungal communities in a cold and fire-prone region.

Temporal and Spatial Features of Phosphatase Activity in Natural and Human-Transformed Soils

Data on phosphatase activity (PA) in soils of different natural zones, intrazonal soils, buried soils, and cultural layers in archaeological monuments of different age were summarized. The variability of PA in soil complexes was analyzed. The maximum values of PA were recorded in the upper horizon of Eutric Retisols, and minimum values were found in Haplic Calcisols of the Baer hills in the Caspian Lowland. In Solonetzes, a wider variation of PA in the A1 horizon was recorded as compared to that in Cambisols and Calcisols. Mean value of PA in the upper horizon of Solonetz was 1.5 times higher than in the upper horizon of Cambisols and Calcisols. The maximum values of PA in the profile of Solonetz were determined in the uppermost 2-cm-thick layer. The B1 horizon of Cambisols and Calcisols had a higher PA in comparison with that in the A1 horizon of these soils, whereas the B1 horizon of Solonetz had a lower PA than that in the A1 horizon. In the paleosols buried under kurgans of different age, PA was higher in paleosols buried in humid epochs than in paleosols buried in arid epochs. Cultural layers of ancient settlements had the maximum variability of PA values. In some cases, in the cultural layers with low organic matter content, the values of PA correlated with the content of phosphates. In the cultural layers with ash and charcoals, the low values of PA were recorded at high phosphate content.

Comparison of the Properties of Humic Acids Extracted from Soils by Alkali in the Presence and Absence of Oxygen

Humic acids (HAs) make up to 30–50% of the soil organic matter, which is the main reservoir of organic carbon in the biosphere. The common isolation protocol for HAs implies alkaline extraction from soils followed by acidification of the extract with HCl to pH 2. International Humic Substances Society (IHSS) recommends isolation of HAs in oxygen-free atmosphere (e.g., under nitrogen or inert gas purging) to prevent oxidative transformations of HAs during the extraction process. In the Russian school of soil science, extraction is usually conducted without the use of nitrogen. In the present work, we compared the physicochemical properties of HAs isolated from A1 horizons of soddy-podzolic soil (Retisol) and chernozem (Chernozem) by 0.1 M NaOH in the presence and absence of oxygen. The soils used in this study represented zonal types of southern taiga and steppe, respectively, and differed markedly with respect to humus formation conditions. The yield of humic substances (Corg content in the extracts), their elemental composition, functional groups content, molecular-weight distributions (gel filtration on Sephadex G-75), paramagnetic properties, and absorption spectra in the visible, UV, and IR regions were studied. For both soils, no statistically significant differences were found in the quantitative yield, molecular weight distribution, absorption spectra in the visible, UV and IR regions between HAs isolated by alkaline extraction in the presence and absence of oxygen. At the same time, for the HAs extracted from the Retisol soil in the presence of oxygen, higher O : C ratios, higher contents of quinone and carboxyl groups, and significantly higher content of free radicals were observed. This was revealed with the use of elemental analysis, potentiometric titration, 1H and 13C NMR spectroscopy, and electron paramagnetic resonance spectroscopy. For the Chernozem HAs, these differences were not observed. The obtained results suggest that partial oxidation of the soil organic matter components takes place during alkaline extraction from the Retisol in the presence of oxygen. In the Chernozem, humification process is apparently accompanied by significant oxidative transformation of organic residues, so the presence of molecular oxygen does not cause further oxidation of HAs under alkaline conditions. Our results indicate that, for the isolation of HAs from the mineral horizons of Chernozems, the use of oxygen-free atmosphere is optional. In the case of Retisols, the use of oxygen-free atmosphere is desirable, especially if it is intended to study the reactions of HA oxidation upon, for example, enzymatic catalysis.

Agrochemical Profile of Sod-Podzolic Soil under Mixed Forrest

The paper examines agrochemical properties and the nitrogen regimen of sod-podzolic soil under a mixed forest of the Cis-Urals. It has been established that the investigated soil is characterized by a highly acidic reaction throughout the profile. It has a pronounced podzolic horizon 10 cm in thickness depleted of calcium and magnesium cations. The humus content sharply decreases from 4.44% in the eluvial–humus horizon to 0.27% in the parent rock. It has been shown that the total nitrogen content decreases from 3318 mg/kg in the A1 horizon to 644 mg/kg in the A2B horizon and then changes insignificantly. The soil is characterized by a high percentage of nonhydrolyzable (64.91%) and not readily hydrolyzable nitrogen (24.81%) and a low content of mineral nitrogen assimilated by plants (2.36%) in the eluvial–humus horizon. It was revealed that the supply of nitrogen mobile forms in forest soil is high, the content of easily hydrolyzable nitrogen is 267.4 mg/kg, and content of mineral nitrogen is 73.8 mg/kg.

Luminescence age constraints on the Pleistocene-Holocene transition recorded in loess sequences across SE Europe

Abstract Here we investigate the timing of the last glacial loess (L1) - Holocene soil (S0) transition recorded in loess-paleosol sequences from SE Europe (Ukraine, Romania, Serbia) by applying comparative luminescence dating techniques on quartz and feldspars. Equivalent dose measurements were carried out using the single-aliquot regenerative-dose (SAR) protocol on silt (4–11 μm) and sand-sized (63–90 μm and coarser fraction when available) quartz. Feldspar infrared stimulated luminescence (IRSL) emitted by 4–11 μm polymineral grains was measured using the post IR-IRSL290 technique. The paleoenvironmental transition from the last glacial loess to the current interglacial soil was characterized using magnetic susceptibility and its frequency dependence. SAR-OSL dating of 4–11 μm, 63–90 μm and 90–125 μm quartz provided consistent ages in the loess-paleosol sites investigated, while the post-IR IRSL290 protocol proved unreliable for dating such young samples. Based on these ages and the threshold of the magnetic signal enhancement the onset of soil formation has been placed around 16.6 ± 1.1 ka at Roxolany (Ukraine), 13.5 ± 0.9 ka at Mosorin (Serbia) and between 17.6 ± 1.4 ka and 12.4 ± 1.0 ka at Râmnicu Sarat (Romania). The trend observed in the magnetic parameters reflects the intensity of pedogenesis induced by regional climate amelioration during the Late Glacial, but the onset of magnetic susceptibility enhancement precedes the stratigraphic boundary of Pleistocene-Holocene dated at 11.7 ka in ice core records. Thus, magnetic susceptibility indicates a gradual increase in pedogenesis after Termination 1 (∼17 ka in the North Atlantic) at the sampling sites. Based on current data, it is not possible to define a synchronous threshold of change for all sections. However, the trend in the magnetic susceptibility data closely reflects the gradual transition from Last Glacial Maximum (LGM) towards the Holocene, with the onset of humus accumulation (A1 horizon) possibly linked to the prevalence of full interglacial conditions.

Drip irrigation wetting patterns and nitrate distribution: comparison between electrical resistivity (ERI), dye tracer, and 2D soil–water modelling approaches

Despite the widespread use of drip irrigation and fertigation, there is limited research on soil wetting patterns and nutrient distribution from drip emitters in agricultural soils. We compared the use of electrical resistivity imaging (ERI) with dye tracer patterns, measured soil nitrate distribution, and modelled changes in soil moisture and nitrate distribution, in a commercial apple orchard in southern Tasmania. Time-lapse two-dimensional ERI revealed wetting plumes beneath the emitters ranged from nil infiltration, to infiltration beyond 1.0 m depth. Lack of infiltration beneath some emitters was attributed to runoff caused by either water repellence or the surface leaf mulch, whilst infiltration to 1.0 m depth was attributed to preferential flow processes. The uncalibrated ERT was unable to discern the separate contributions from of solute concentration, moisture content and temperature to the change in electrical resistivity. The dye tracer study revealed the majority of the fertigated nitrate was retained in the A1 horizon, whilst the fertigated water infiltrated much deeper into the A2 and B2 horizons. The 2D modelling was not able to replicate the variations in infiltration demonstrated by the ERT, principally due to the lumped nature of the soil parameterisation, and inability of the model to simulate preferential flow. As such, use of modelling tools and texture-based guidelines for design and management of drip emitters is not recommended for the texture contrast soils.

Harcosnők klubja? – Specializált társadalmi helyzetű nők a késő rézkor időszakában Magyarországon

This article focus on the status of the woman in the main cultures (Baden complex and Yamna) of the Late Copper Age (3600–2800 BC) and the transitional period (2800–2600 BC). Although the Bell Beaker complex belongs to the Early Bronze Age in Hungary (2500–1900 BC), in European terminologies it is a Late Neolithic culture and belongs to the Reinecke A0 horizon in its late phase, which is why I included it into my research. I identify charismatic people displaying signs of agression in these three culture complexes, whose personalities are associated with warfare. In all three cultures there were women with specialised status: their knowledge, property and profession raised them above the average man and woman.

Saccharides of ectomycorrhizal fungal sclerotia as sources of forest soil polysaccharides

ABSTRACTThe neutral monosaccharide composition of forest soils differs from that of non-forest soils suggesting there is an accumulation of microbial saccharides. Ectomycorrhizal (ECM) fungi can be responsible as the fungi are typical in forest soils. We investigated neutral saccharides of ECM fungal sclerotia to determine what part it might play in the origin of forest soil polysaccarides. Sclerotial grain (SG) was collected from the O, A1 and A2 horizons of a soil of subalpine forest of Mt. Ontake, central Japan. Neutral saccharides in soil and SG were analyzed by two step hydrolysis with sulfuric acid and gas-chromatography of alditol acetate derivatives. Saccharides accounted for 6.0−16% of the SG by carbon content. The SG contained predominantly easily hydrolysable (EH)-glucose, which accounted for 75–85% of the composition depending on grain size and the soil horizon, followed by mannose (7.7−15%), galactose (2.2−4.8%) and non-easily hydrolysable (NEH)-glucose (1.7−6.1%). The SG contained all of these sugars irrespective of its size. The SG collected from the A1 and A2 horizons contained all sugar components found in that from the O horizon, except for fucose in that from A2 horizon. The monosaccharide composition of SG indicates that accumulation of ECM fungal sclerotial polysaccharides might have been responsible for enlarging the molar ratios of (galactose + mannose) /(arabinose + xylose) and EH-glucose/NEH-glucose of forest soils. The proportions of SG saccharides relative to soil saccharides were 3.6, 1.2, and 0.83% for the O, A1 and A2 horizons, respectively. These levels of the proportion are considerable as ECM fugal sclerotia are the products of a limited species among hundreds and thousands of microbial species inhabiting forest soils. The sclerotia forming ECM fungal species such as Cenococcum geophilum may be key sources of forest soil polysaccharides.

Erratum to: Chemical contamination in upper horizon of Haplic Chernozem as a transformation factor of its physicochemical properties

The effect of Cu, Zn, and Pb high rates on the physical properties and organic matter of Haplic Chernozem (Clayic) (A1 horizon 0–20 cm) under model experimental conditions was studied. In a model experiment, soil samples of Haplic Chernozem (Clayic) were artificially contaminated with 2000 mg/kg of Cu, Zn, and Pb acetates added separately. The particle-size fraction, the microaggregates distribution, the structural status, the total content and fractional and group composition of organic matter, physico-mechanical properties were determined in soil without metals and soil contaminated with metals. At the soil contamination with Cu, Zn, and Pb, the content of organo-mineral colloids increased, which results to the increasing of the clay fraction content by 4.5% compared to the control. The analysis of the microaggregate size composition of the studied soil shows that the content of coarser aggregates (1–0.25 mm) increases and the content of finer (0.05–0.001 mm) aggregates decreases after the addition of HMs and correspond to the HMs series: Cu → Zn → Pb. A significant decrease in the coefficient of water stability in the control from 3.0 to 1.4–1.5 in the contaminated treatments. The structural status (estimated from total agronomically valuable aggregates) changes from excellent to good. The addition of Cu, Zn, and Pb to the soil affects the quantitative composition of organic matter. The contents of free and sesquioxide-bound humic acids and free fulvic acids increased. The contamination with Zn and Pb causes the aliphatization of organic matter. Under conditions of model experiment, the contamination of Haplic Chernozem (Clayic) with high rates of Cu, Zn, and Pb leads to changes of the microaggregates distribution, the structural status, and the qualitative composition of organic matter.