Pedogenic processes in loess-paleosol sediments: Clues from Li isotopes of leachate in Luochuan loess

Author(s):  
Mao-Yong He ◽  
Ji-Bao Dong ◽  
Zhangdong Jin ◽  
Chun-Yao Liu ◽  
Jun Xiao ◽  
...  
Keyword(s):  
2011 ◽  
Vol 91 (5) ◽  
pp. 889-902 ◽  
Author(s):  
J. J. Miller ◽  
J. A. Brierley

Miller, J. J. and Brierley, J. A. 2011. Solonetzic soils of Canada: Genesis, distribution, and classification. Can. J. Soil Sci. 91: 889–902. Soils of the Solonetzic order are defined as having a Solonetzic B horizon designated as a Bn or Bnt horizon. The Solonetzic Order includes four great groups: Solonetz, Solodized Solonetz, Solod, and Vertic Solonetz. Solonetzic soils are thought to develop via the stepwise pedogenic processes of salinization, solonization (desalinzation and alkalization), and solodization. Soluble salts are brought into the soil pedon of Solonetzic soils by capillary movement and evaporation from spring to fall, and upward water flow from the water table to the freezing zone in the winter deposits salts upon freezing. Solonization proceeds when desalinization lowers the total salt content and alkalization is initiated by high exchangeable Na. Solodization occurs when anisotropic flow conditions or a change in vertical hydraulic gradients prevent capillary rise and replenishment of soluble Na in the Bn horizon. Two common Solonetzic catenas are found in the prairies. In the first sequence, Gleyed Solonetz or Solonetz occur in the depressional areas of the landscape, and soils then grade through Solodized Solonetz, Solods, and in some cases, Chernozems or normal zonal soils at higher elevations. In the second sequence, Solods are found in the lowest topographic position, while Solodized Solonetz, Solonetz and Chernozems are found at progressively higher slope positions. Solonetzic soils have unique properties that adversely affect their use for agriculture and other land uses (e.g., construction, septic systems). Further interdisciplinary research is required to better understand the genesis of these soils at the “meter scale” or local landscape level because of the extreme spatial variability of these soils.


2014 ◽  
Vol 40 (2) ◽  
pp. 271-281
Author(s):  
ABMS Islam ◽  
ZH Khan ◽  
AR Mazumder

Twenty two soil samples from four pedons representing some established soil series namely Jaonia, Haiti, Taras and Digli from the Chalan beel area of Bangladesh were studied in the field as well as in the laboratory for their pedogenesis and characterization. All the soils are heavy textured with clay contents ranging from 47 to 60 percent. The soils are moderately acidic to neutral in reaction with high base saturation. The soils have developed redoximorphic features including redox concentration and redox depletion due to periodic flooding more than 4 months in the monsoon season. Development of cambic horizon in these soils is the most notable morphogenetic feature. Gleization and weak hydromorphism are the dominant pedogenic processes. At the subgroup level the soiis were classified as Typic Endoaquepts and Aerie Endoaquepts. Finally the soiis are characterized at the family level of soil taxonomy. Asiat. Soc. Bangladesh, Sci. 40(2): 271-281, December 2014


2021 ◽  
Author(s):  
Moska Piotr ◽  
Sokołowski Robert ◽  
Jary Zdzisław ◽  
Zieliński Paweł ◽  
Raczyk Jerzy ◽  
...  

<p>Multi-proxy studies (including sedimentological, pedological, radiocarbon and optically stimulated luminescence dating methods) were used to establish origin and chronology of depositional processes in the type section Mierzyn, central Poland. The investigated key site is located in the extraglacial zone of the Last Glaciation, ca. 130 km to the south from the Last Glacial Maximum in the Luciąża river valley area. In the studied profile (16 m thick) two lithofacial complexes were identified. The lower, fluvio-aeolian complex consists of silty-sandy sediments (1.6 m) deposited. The final phase of fluvio-aeolian deposition is expressed by initial pedogenic processes. Above is located aeolian complex (13 m of thickness). Three aeolian units are separated by two palaeosols.</p><p>To establish stratigraphic framework of depositional and pedogenic processes, four samples for radiocarbon dating from palaeosols and twelve samples for OSL dating from sandy units were collected. The obtained results reveal very good agreement of both absolute dating methods. It led to reconstruct chronology of main palaeoenvironmental changes. The fluvio-aeolian complex and the lowermost part of aeolian complex (below the lower palaeosol) were deposited in the Oldest Dryas in relatively cool and dry climate conditions. The amelioration of climate in the Bølling interstadial caused development of pedogenic processes expressed by 0.3 m thick palaeosol. Main part of aeolian complex (10 m of thickness) was deposited in the Older Dryas. The upper palaeosol developed in the Allerød interstadial as a result of the next amelioration of the climate. During the Younger Dryas was deposited the uppermost part of aeolian complex.</p><p>Classic development of fluvial to- aeolian succession in the Mierzyn site as well as detailed chronology based on two independent absolute age methods reveal that it can be treated as stratotype for the Late Glacial and correlated with other type sections in the Central and Western Europe.</p><p><strong>Ackowledgments</strong></p><p>Presented results were obtained with support of Polish National Science Centre, contract number 2018/30/E/ST10/00616.</p><p> </p>


Soil Research ◽  
2020 ◽  
Vol 58 (2) ◽  
pp. 174
Author(s):  
Markus Anda ◽  
Erna Suryani ◽  
Dedi Nursyamsi

Effect of long-term wet and dry (redox) cycles attributed to seasonally flooded soils in rotation of rice and upland food crops on soil characteristics is not yet available in modern agriculture. The objective of this study was to assess soil morphological features, mineralogical compositions and dynamic pedogenic processes under rotation of rice and honey-taste sweet potato. Four profiles that experienced redox cycles and one that did not (as a control) were sampled for soil analyses. Results showed that all soil profiles, irrespective of redox cycles, derived from similar parent materials as revealed by the same type of weatherable mineral contents (hornblende, labradorite, hypersthene, and olivine or muscovite), ranging within 27–84%. High proportions of easily weatherable minerals corresponded to the high availability of Ca, Mg, Si, Fe, Mn and Cu nutrients, suggesting the release of nutrient reserves from weatherable minerals. In all soils, the clay fraction contained only the one mineral, halloysite. Long-term redox cycles due to rotation of rice–honey-taste sweet potato resulted in a remarkable pedomorphic feature, i.e. discrete large soft black Mn segregation with the highest accumulation in the middle part of soil profiles. Other pedogenic processes were Ca, Mg, and Si translocation from the upper to lower layers of soil profiles, but Fe was retained in the uppermost two horizons. We proposed a new soil classification ‘Manganic Eutrudept’ as a subgroup category to accommodate the soil property of high soft Mn segregation.


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