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Peter Kühn - One of the best experts on this subject based on the ideXlab platform.
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Distribution of Chernozems and Phaeozems in Central Germany during the Neolithic period
Quaternary International, 2019Co-Authors: Hans Von Suchodoletz, Christian Tinapp, Tobias Lauer, Bruno Glaser, Harald Stäuble, Peter Kühn, Christoph ZielhoferAbstract:Abstract A well-based knowledge about the former distribution of Chernozems and Phaeozems is necessary to (i) better understand the factors influencing formation and degradation of these highly fertile soils, and (ii) better explain prehistoric settlement patterns that were also determined by natural factors such as soil fertility. During this archaeopedological study carried out in Central Germany we applied sedimentological and micromorphological methods to compare soils and pedosediments from the recent Chernozem/Phaeozem region with black-coloured pedosediments buried in early Neolithic structures of the recent Luvisol area directly to the east. Relocated clay coatings and significantly lower magnetic enhancement compared to Chernozem/Phaeozem-derived material were found in most black-coloured pedosediments in the Luvisol area. This demonstrates that despite their location next to an extensive Chernozem/Phaeozem area these sediments do not originate from Chernozems or Phaeozems. Instead, their dark colour must either originate from anthropogenic input similar to black-coloured Anthrosols (“Dark Earth”), or must stem from Ah-material of former Luvisols. Consequently, may be apart from a small relatively dry and carbonate-rich Luvisol region northwest of Leipzig there was obviously no significantly larger distribution of Neolithic Chernozems and Phaeozems in this region during the past. Consequently, the regional early Neolithic settlers of the Linear Pottery Culture settled intensively also in areas outside the distribution of Chernozems and Phaeozems, and the activities of these settlers did not lead to the formation of such soils. Thus, fertile soils were obviously only one factor among probably others to explain the regional Neolithic settlement pattern. Significantly lower carbonate contents were found for the parent material of the black-coloured pedosediments in the Luvisol region compared with the parent material of Chernzems and Phaeozems. This demonstrates that the decisive factor to explain the recent and former spatial distribution of Chernozems and Phaeozems in this relatively dry area is the carbonate dynamics. Anthropogenic activity since the early Neolithic period obviously helped to preserve the naturally formed Chernozems and Phaeozems by re-carbonatization processes, but humans were not the main soil forming factor in early settled regions.
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micromorphology and late glacial holocene genesis of Luvisols in mecklenburg vorpommern ne germany
Catena, 2003Co-Authors: Peter KühnAbstract:Abstract In the German soil science literature, Luvisols formed in Weichselian sediments (except from the Early Weichselian) are normally regarded as purely Holocene soils with the main period of development assumed to have been during the Atlantic phase. Although debated at some length since the 1960s, the genesis of the widespread albic Luvisols, with a simplified Ap/Bw/(Eb)/(EBtb)/Btb(g)/C horizon sequence and developed on the flat and slightly undulating till plains of the north German Mecklenburgian Stage (deglaciation ∼14 000 BP), has yet to be clarified. Periglacial climate during the Late Weichselian led to the formation of sand-filled wedge-shaped structures penetrating Bt horizons. Systematic micromorphologic investigations of soil profiles with sand wedges revealed the occurrence of numerous fragments of rounded limpid clay coatings within periglacial formed lenticular microplates as well as in and at the margins of the sand wedge infillings. Assuming the Younger Dryas as the latest possible phase of formation, the lenticular microplates and the undisturbed sand wedges postdate clay illuviation. Undisrupted clay coatings next to fragmented clay coatings prove a subsequent Holocene clay illuviation. Clay illuviation must have occurred at least in warmer phases of the Late Glacial, together with the already accepted pedogenic processes of decalcification, organic matter accumulation (Ahb horizons), podzolisation and silicate weathering (Bwb horizons) on sites not influenced by groundwater.
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Micromorphology and Late Glacial/Holocene genesis of Luvisols in Mecklenburg¿Vorpommern (NE-Germany)
CATENA, 2003Co-Authors: Peter KühnAbstract:Abstract In the German soil science literature, Luvisols formed in Weichselian sediments (except from the Early Weichselian) are normally regarded as purely Holocene soils with the main period of development assumed to have been during the Atlantic phase. Although debated at some length since the 1960s, the genesis of the widespread albic Luvisols, with a simplified Ap/Bw/(Eb)/(EBtb)/Btb(g)/C horizon sequence and developed on the flat and slightly undulating till plains of the north German Mecklenburgian Stage (deglaciation ∼14 000 BP), has yet to be clarified. Periglacial climate during the Late Weichselian led to the formation of sand-filled wedge-shaped structures penetrating Bt horizons. Systematic micromorphologic investigations of soil profiles with sand wedges revealed the occurrence of numerous fragments of rounded limpid clay coatings within periglacial formed lenticular microplates as well as in and at the margins of the sand wedge infillings. Assuming the Younger Dryas as the latest possible phase of formation, the lenticular microplates and the undisturbed sand wedges postdate clay illuviation. Undisrupted clay coatings next to fragmented clay coatings prove a subsequent Holocene clay illuviation. Clay illuviation must have occurred at least in warmer phases of the Late Glacial, together with the already accepted pedogenic processes of decalcification, organic matter accumulation (Ahb horizons), podzolisation and silicate weathering (Bwb horizons) on sites not influenced by groundwater.
Bruno Delvaux - One of the best experts on this subject based on the ideXlab platform.
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Cation exchange resin and test vermiculite to study soil processes in situ in a toposequence of Luvisol and Cambisol on loess
European Journal of Soil Science, 2001Co-Authors: Vincent Brahy, Bruno DelvauxAbstract:Both the ion accumulation on cation exchange resin and the transformation of test vermiculite in situ have been used to identify current processes in acid forest soils. We used such test materials to study weathering in a toposequence Dystric Luvisol-Spodo-Dystric Cambisol on loess under deciduous forest in Belgium. The resin and a trioctahedral vermiculite were inserted for 2 years in the major horizons, down to a depth of 60 cm. The cation accumulation on the resin revealed that four main acid-consuming systems are currently active in the toposequence. With decreasing acid neutralizing capacity, these systems are in the Luvisols: (i) the pool of exchangeable bases, (ii) the Al-bearing minerals controlling the Al concentration in the liquid phase; and in the podzolized Cambisols: (iii) the less weatherable K-bearing minerals, (iv) the Mg-bearing phyllosilicates made free of Al interlayers in complexing conditions. The loss of cation exchange capacity in the test vermiculite is related to Al interlayering. However, this process masks a significant interlayer accumulation of magnesium, which is generated by the weathering of the test mineral itself. The largest interlayer accumulation of Mg occurs in the podzolized Cambisol, suggesting more intense weathering of the test vermiculite in this soil.
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Estimation of soil weathering stage and acid neutralizing capacity in a toposequence Luvisol-Cambisol on loess under deciduous forest in Belgium
European Journal of Soil Science, 2000Co-Authors: Vincent Brahy, J. Deckers, Bruno DelvauxAbstract:Soils derived from loess are extensive in Europe and are well suited for forestry. They are suspected to be poor acid buffers, however. We have estimated the weathering stage and acid neutralizing capacity of acid soils under forest in a toposequence on loess in the Belgian silt belt. The soils vary distinctly in morphology and physico-chemical properties according to their topographic position. Dystric Cambisols have developed in colluvial deposits in the dry valley floors, whereas Dystric Luvisols have formed on the slopes in a rejuvenated material. The Cambisols are more acid and less saturated in bases than are Luvisols. They are strongly depleted of clay and contain less weatherable minerals. Easily weatherable minerals are concentrated mainly in the clay fraction of both soil types. Clay minerals of size < 2 mu m therefore act as major sinks for protons in these soils. A simplified expression taking into account the total reserve in bases, total aluminium and iron occluded in silicates is used to estimate acid neutralizing capacity. Our estimates confirm that these acid loessic soils are indeed poor acid buffers. They show that the Dystric Cambisols depleted of clay are sensitive to potential acidification, whether natural or man-made.
Sokrat Sinaj - One of the best experts on this subject based on the ideXlab platform.
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spatial variability of potassium in agricultural soils of the canton of fribourg switzerland
Geoderma, 2017Co-Authors: Guillaume Blanchet, Zamir Libohova, Nicolas Rossier, Stéphane Joost, B Jeangros, Andre Schneider, Sokrat SinajAbstract:Abstract Potassium (K) is a crucial element for plant nutrition and its availability and spatial distribution in agricultural soils is influenced by many agro-environmental factors. In Switzerland, a soil monitoring network (FRIBO) was established in 1987 with 250 sites distributed over the whole of the canton of Fribourg (representing 4% of the surface area of Switzerland), whose territory is shared between the Swiss Midlands and the Western Alp foothills. In this study area, diverse geological deposits (sandstone, marlstone, silts and calcareous rocks), soil types (Cambisols, Gleysols, Rendzinas, Luvisols and FLuvisols) and land uses (cropland, permanent grassland and mountain pasture) are present, making the network interesting for assessing the relative contribution of environmental variables and land use management on soil properties. The aims of the present study were to (i) characterize the soil K status in the Fribourg canton according to four different extraction methods; (ii) analyse the spatial variability of soil K in relation to land use, soil type, soil parent material and topography; (iii) evaluate the spatial predictability of K at the canton level; and (iv) analyse the implications for K fertilization management. The overall amount of soil total K averaged 13.6 g·kg − 1 with significant variations across the sites (5.1–22.1 g·kg − 1 ). The spatial distribution of total K content was influenced by relatively extended soil forming processes, as suggested by (i) a significant global spatial autocorrelation measure at the 10 km scale (Moran's I = 0.43); (ii) significant differences observed among soil types and soil parent materials and (iii) significant correlations with land attributes such as elevation ( r = − 0.51). On the other hand, available mean K forms were significantly different among land uses, with the highest mean values of available K encountered in permanent grasslands, from 46.3 mg·kg − 1 (water extraction) to 198 mg·kg − 1 (acetate ammonium + EDTA extraction). All K forms (total and available) showed similar spatial regional patterns for all spatial interpolation methods, with areas dominated by permanent grassland and crops presenting higher values. However, these trends were less pronounced for the available K forms due to the prevalence of on-farm management practices for these K forms ( e.g. fertilization), likely inducing high spatial and temporal variability. This hypothesis was supported by spatial clustering of low and/or high K fertility status that could be related to local particular farming practices. Grasslands require particular attention with regard to overall high K fertility status.
Milan Mesić - One of the best experts on this subject based on the ideXlab platform.
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Runoff and soil loss under different tillage methods on Stagnic Luvisols in central Croatia
Soil & Tillage Research, 2001Co-Authors: Ferdo Bašić, Ivica Kisić, Anđelko Butorac, Othmar Nestroy, Milan MesićAbstract:Abstract Owing to humid climate and unfavourable relief, the problem of extensive soil erosion in central Croatia is of prime importance. The main objective of this research was to determine how soil erosion is influenced by deep (30 cm) soil tillage practised for deep-rooted row crops in comparison with other tillage methods, on Stagnic Luvisols. Soil loss quantity was recorded during the 4-year investigation cycle (1994–1998), under common field crops grown under six tillage methods. Appreciably higher rates of soil erosion were recorded in low-density row spring crops than in high-density winter crops under the same tillage methods. The time immediately following the sowing of spring crops was the most critical period, i.e. the period when highest soil loss occurs. The results showed that erosion processes cannot be completely stopped; however, they can be reduced to an acceptable level by an appropriate tillage method. Efficient soil conservation on Stagnic Luvisols was achieved by no-tillage and all across the slope tillage methods.
Jingkuan Wang - One of the best experts on this subject based on the ideXlab platform.
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Dynamics of maize carbon contribution to soil organic carbon in association with soil type and fertility level.
PloS one, 2015Co-Authors: Jiubo Pei, John Farmer, Jingkuan WangAbstract:Soil type and fertility level influence straw carbon dynamics in the agroecosystems. However, there is a limited understanding of the dynamic processes of straw-derived and soil-derived carbon and the influence of the addition of straw carbon on soil-derived organic carbon in different soils associated with different fertility levels. In this study, we applied the in-situ carborundum tube method and 13C-labeled maize straw (with and without maize straw) at two cropland (Phaeozem and Luvisol soils) experimental sites in northeast China to quantify the dynamics of maize-derived and soil-derived carbon in soils associated with high and low fertility, and to examine how the addition of maize carbon influences soil-derived organic carbon and the interactions of soil type and fertility level with maize-derived and soil-derived carbon. We found that, on average, the contributions of maize-derived carbon to total organic carbon in maize-soil systems during the experimental period were differentiated among low fertility Luvisol (from 62.82% to 42.90), high fertility Luvisol (from 53.15% to 30.00%), low fertility Phaeozem (from 58.69% to 36.29%) and high fertility Phaeozem (from 41.06% to 16.60%). Furthermore, the addition of maize carbon significantly decreased the remaining soil-derived organic carbon in low and high fertility Luvisols and low fertility Phaeozem before two months. However, the increasing differences in soil-derived organic carbon between both soils with and without maize straw after two months suggested that maize-derived carbon was incorporated into soil-derived organic carbon, thereby potentially offsetting the loss of soil-derived organic carbon. These results suggested that Phaeozem and high fertility level soils would fix more maize carbon over time and thus were more beneficial for protecting soil-derived organic carbon from maize carbon decomposition.
