What is clay? A new definition of “clay” based on plasticity and its impact on the most widespread soil classification systems

2018 ◽  
Vol 161 ◽  
pp. 57-63 ◽  
Author(s):  
José Manuel Moreno-Maroto ◽  
Jacinto Alonso-Azcárate
1985 ◽  
Vol 65 (2) ◽  
pp. 283-291 ◽  
Author(s):  
W. H. HENDERSHOT

Thirteen pedons in an arctic environment were classified according to the Canadian and American systems of soil classification. Major differences in groupings result from the contrasting approaches. Although the definition used in Canada to define Cryosols is sometimes difficult to apply in the field, the underlying concept is valid, since soils with permafrost at a shallow depth should be separated at the highest level of classification. The American system virtually ignores the influence of permafrost on pedogenesis. Its reliance on soil temperature regimes at both the great group and subgroup levels is redundant. It is suggested that the definition of Cryosols, in the Canadian system, be changed to include strongly cryoturbated soils with very cold or colder soil temperature regimes. The American system should be altered to provide for pergelic great groups; in addition permafrost and strong cryoturbation should be used to create new subgroups. The requirement that a cambic horizon have a texture finer than loamy fine sand should be waived in soils having cryic or pergelic soil temperature regimes. Key words: Cryosols, cryoturbated soils, permafrost, pergelic soils


2019 ◽  
Vol 70 (3) ◽  
pp. 184-192
Author(s):  
Cezary Kabała

Abstract The Soil Science Society of Poland has elected chernozem to be the Soil of the Year 2019. Although chernozems cover less than 2% of Poland, they have high importance for agriculture due to their productivity and play a specific scientific role for understanding of soil development and functioning in an environment. Chernozems are also crucial for the reconstruction of Neolithic agriculture development and human impacts on soil and landscape. This introductory paper presents (a) a specific definition of chernozem in Poland, connected with a separate distinction of black earths and colluvial chernozemic soils; (b) a review of the present and former classification schemes for chernozems in Poland and their correlation with international soil classification systems (WRB and Soil Taxonomy); (c) the spatial distribution of chernozems in Poland, their agricultural evaluation and threats for chernozems’ quality and future existence related to intense land use.


Author(s):  
Murad Y. Abu-Farsakh ◽  
Zhongjie Zhang ◽  
Mehmet Tumay ◽  
Mark Morvant

Computerized MS-Windows Visual Basic software of a cone penetration test (CPT) for soil classification was developed as part of an extensive effort to facilitate the implementation of CPT technology in many geotechnical engineering applications. Five CPT soil engineering classification systems were implemented as a handy, user-friendly, software tool for geotechnical engineers. In the probabilistic region estimation and fuzzy classification methods, a conformal transformation is first applied to determine the profile of soil classification index (U) with depth from cone tip resistance (qc) and friction ratio (Rf). A statistical correlation was established in the probabilistic region estimation method between the U index and the compositional soil type given by the Unified Soil Classification System. Conversely, the CPT fuzzy classification emphasizes the certainty of soil behavior. The Schmertmann and Douglas and Olsen methods provide soil classification charts based on cone tip resistance and friction ratio. However, Robertson et al. proposed a three-dimensional classification system that is presented in two charts: one chart uses corrected tip resistance (qt) and friction ratio (Rf); the other chart uses qt and pore pressure parameter (Bq) as input data. Five sites in Louisiana were selected for this study. For each site, CPT tests and the corresponding soil boring results were correlated. The soil classification results obtained using the five different CPT soil classification methods were compared.


2011 ◽  
pp. 25-33
Author(s):  
Rosangela Invernizzi ◽  
Agnese Filocco

Myelodysplastic syndromes (MDS) are acquired clonal disorders of hematopoiesis, that are characterized most frequently by normocellular or hypercellular bone marrow specimens, and maturation that is morphologically and functionally dysplastic. MDS constitute a complex hematological problem: differences in disease presentation, progression and outcome have made it necessary to use classification systems to improve diagnosis, prognostication and treatment selection. On the basis of new scientific and clinical information, classification and prognostic systems have recently been updated and minimal diagnostic criteria forMDS have been proposed by expert panels. In addition, in the last few years our ability to define the prognosis of the individual patient with MDS has improved. In this paper World Health Organization (WHO) classification refinements and recent prognostic scoring systems for the definition of individual risk are highlighted and current criteria are discussed. The recommendations should facilitate diagnostic and prognostic evaluations in MDS and selection of patients for new effective targeted therapies.


Soil Research ◽  
2020 ◽  
Vol 58 (6) ◽  
pp. 519
Author(s):  
H. F. Teng ◽  
R. A. Viscarra Rossel ◽  
R. Webster

Differences between local systems of soil classification hinder the communication between pedologists from different countries. The FAO–UNESCO Soil Map of the World, as a fruit of world-wide collaboration between innumerable soil scientists, is recognised internationally. Ideally, pedologists should be able to match whole classes in their local systems to those in an international soil classification system. The Australian Soil Classification (ASC) system, created specifically for Australian soil, is widely used in Australia, and Australian pedologists wish to translate the orders they recognise into the FAO soil units when writing for readers elsewhere. We explored the feasibility of matching soil orders in the ASC to units in the FAO legend using a multivariate analysis. Twenty soil properties, variates, of 4927 profiles were estimated from their visible–near infrared reflectance (vis–NIR) spectra. We arranged the profiles in a Euclidean 20-dimensional orthogonal vector space defined by standardised variates. Class centroids were computed in that space, and the Euclidean distances between the centroids of the ASC orders and units in the FAO scheme were also computed. The shortest distance between a centroid of any ASC order and one of units in the FAO classification was treated as a best match. With only one exception the best matches were those that an experienced pedologist might expect. Second and third nearest neighbours in the vector space provided additional insight. We conclude that vis–NIR spectra represent sufficiently well the essential characters of the soil and so spectra could form the basis for the development of a universal soil classification system. In our case, we could assign with confidence the orders of the ASC to the units of the FAO scheme. A similar approach could be applied to link other national classification systems to one or other international systems of soil classification.


2018 ◽  
Vol 48 (2) ◽  
pp. 76-86 ◽  
Author(s):  
Jennie Shepheard ◽  
Elsa Lapiz ◽  
Carla Read ◽  
Terri J Jackson

Background: The Council of Australian Governments has focused the attention of health service managers and state health departments on a list of hospital-acquired complications (HACs) proposed as the basis of funding adjustments for poor quality of hospital inpatient care. These were devised for the Australian Commission on Safety and Quality in Health Care as a subset of their earlier classification of hospital-acquired complications (CHADx) and designed to be used by health services to monitor safety performance for their admitted patients. Objective: To improve uptake of both classification systems by clarifying their purposes and by reconciling the ICD-10-AM code sets used in HACs and the Victorian revisions to the CHADx system (CHADx+). Method: Frequency analysis of individual clinical codes with condition onset flag (COF 1) included in both classification systems using the Victorian Admitted Episodes Dataset for 2014/2015 ( n = 2,623,275 separations). Narrative description of the resulting differences in definition of “adverse events” embodied in the two systems. Results: As expected, a high proportion of ICD-10-AM codes used in the HACs also appear in CHADx+, and given the wider scope of CHADx+, it uses a higher proportion of all COF 1 diagnoses than HACs (82% vs. 10%). This leads to differing estimates of rates of adverse events: 2.12% of cases for HACs and 11.13% for CHADx+. Most CHADx classes (70%) are not covered by the HAC system; discrepancies result from the exclusion from HACs of several major CHADx+ groups and from a narrower definition of detailed HAC classes compared with CHADx+. Case exclusion criteria in HACs (primarily mental health admissions) resulted in a very small proportion of discrepancies (0.13%) between systems. Discussion: Issues of purpose and focus of these two Australian systems, HACs for clinical governance and CHADx+ for local quality improvement, explain many of the differences between them, and their approach to preventability, and risk stratification. Conclusion: A clearer delineation between these two systems using routinely coded hospital data will assist funders, clinicians, quality improvement professionals and health information managers to understand discrepancies in case identification between them and support their different information needs.


Author(s):  
Eric A. J. Hoste ◽  
John A. Kellum ◽  
Norbert Lameire

The lack of a precise biochemical definition of acute kidney injury (AKI) resulted in at least 35 definitions in the medical literature, which gave rise to a wide variation in reported incidence and clinical significance of AKI, impeded a meaningful comparison of studies.The first part of this chapter describes and discusses different definitions and classification systems of AKI. Patient outcome and the need for renal replacement therapy are directly related to the severity of AKI, an observation that supports the use of a categorical staging system rather than a simple binary descriptor. The severity of AKI is commonly characterized using the relative changes in serum creatinine and urine output. Recently introduced staging systems including the RIFLE classification and the Acute Kidney Injury Network (AKIN) use these relatively simple and readily available parameters allowing the assignment of individual patients to different AKI stages. More recently, a Kidney Disease: Improving Global Outcomes (KDIGO) workgroup developed a consensus-based AKI staging system drawing elements of both RIFLE and AKIN. The potential pitfalls and limitations of the proposed definitions and classifications are briefly described.The second part of the chapter describes the epidemiology of AKI in different clinical settings; the intensive care unit (ICU), the hospitalized population, and the community. The different spectrum of AKI in the emerging countries is discussed and the most important causes and aetiologies of the major clinical types of AKI, prerenal, renal, and post-renal are summarized in table form. Finally the patient survival and renal functional outcome of AKI are briefly discussed


Author(s):  
Tibor Tóth

Soil salinity has been causing problems for agriculturists for millennia, primarily in irrigated lands. The importance of salinity issues is increasing, since large areas are affected by irrigation-induced salt accumulation. A wide knowledge base has been collected to better understand the major processes of salt accumulation and choose the right method of mitigation. There are two major types of soil salinity that are distinguished because of different properties and mitigation requirements. The first is caused mostly by the large salt concentration and is called saline soil, typically corresponding to Solonchak soils. The second is caused mainly by the dominance of sodium in the soil solution or on the soil exchange complex. This latter type is called “sodic” soil, corresponding to Solonetz soils. Saline soils have homogeneous soil profiles with relatively good soil structure, and their appropriate mitigation measure is leaching. Naturally sodic soils have markedly different horizons and unfavorable physical properties, such as low permeability, swelling, plasticity when wet, and hardness when dry, and their limitation for agriculture is mitigated typically by applying gypsum. Salinity and sodicity need to be chemically quantified before deciding on the proper management strategy. The most complex management and mitigation of salinized irrigated lands involves modern engineering including calculations of irrigation water rates and reclamation materials, provisions for drainage, and drainage disposal. Mapping-oriented soil classification was developed for naturally saline and sodic soils and inherited the first soil categories introduced more than a century ago, such as Solonchak and Solonetz in most of the total of 24 soil classification systems used currently. USDA Soil Taxonomy is one exception, which uses names composed of formative elements.


Land ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 154 ◽  
Author(s):  
Orestis Kairis ◽  
Vassiliki Dimitriou ◽  
Chrysoula Aratzioglou ◽  
Dionisios Gasparatos ◽  
Nicholas Yassoglou ◽  
...  

Two soil mapping methodologies at different scales applied in the same area were compared in order to investigate the potential of their combined use to achieve an integrated and more accurate soil description for sustainable land use management. The two methodologies represent the main types of soil mapping systems used and still applied in soil surveys in Greece. Diomedes Botanical Garden (DBG) (Athens, Greece) was used as a study area because past cartographic data of soil survey were available. The older soil survey data were obtained via the conventional methodology extensively used over time since the beginnings of soil mapping in Greece (1977). The second mapping methodology constitutes the current soil mapping system in Greece recently used for compilation of the national soil map. The obtained cartographic and soil data resulting from the application of the two methodologies were analyzed and compared using appropriate geospatial techniques. Even though the two mapping methodologies have been performed at different mapping scales, using partially different mapping symbols and different soil classification systems, the description of the soils based on the cartographic symbols of the two methodologies presented an agreement of 63.7% while the soil classification by the two taxonomic systems namely Soil Taxonomy and World Reference Base for Soil Resources had an average coincidence of 69.5%.


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