scholarly journals On soil genesis in temperate humid climate. 3. Some other soil groups

1964 ◽  
Vol 12 (3) ◽  
pp. 190-203
Author(s):  
J. van Schuylenborgh
1963 ◽  
Vol 11 (1) ◽  
pp. 10-12
Author(s):  
J. Van Schuylenborgh

The SiO2, A12O3 & Fe2O3 contents of the non-clay fraction of podzol, gray-brown podzolic, brown podzolic, acid brown earth & gley soils were calculated from the soil & clay composition. Results which are tabulated with the silica-ses-quioxide ratios show that the translocation of Fe & Al is fundamentally the same process. Although Al migrates with the clay minerals, if there is clay eluviation, weathering resulting in the liberation of A12O3 & Fe2O3, and subsequent translocation by organic acids are more important. (Abstract retrieved from CAB Abstracts by CABI’s permission)


1962 ◽  
Vol 10 (2) ◽  
pp. 127-144
Author(s):  
J. Van Schuylenborgh

Profiles of humus-iron and humus podzols, gray-brown podzolic soils, acid brown earths, brown podzolic soils and gley soils are described. Podzols developed on very poor acid parent material (low in silt and low in clay, i.e.


1970 ◽  
Vol 18 (3) ◽  
pp. 207-214 ◽  
Author(s):  
J. Van Schuylenborgh ◽  
S. Slager ◽  
A.G. Jongmans

The active soil-forming processes occurring in a Holocene alluvial deposit were: the formation, along voids, of illuvial cutans consisting of clay minerals, Fe oxide and fine matric components (matriferriargillans), differential movement of clay minerals, kaolinite being most mobile; partial transformation of smectites into kandites; disturbance of cutans by biological activity resulting in the formation of papules; redox processes leading to the formation of micro-segregation of Fe oxide. The difference in character and location of matriferriargillans and ferriargillans is discussed. The former are thought to have been synthesized in the Holocene period and the latter in Pleistocene times. The soil is classifiable as a dystric eutrochrept, but as plasma movement generally occurs only in "dystric" (decalcified) material, the soil could be classified as a "udalfic" eutrochrept. (Abstract retrieved from CAB Abstracts by CABI’s permission)


1964 ◽  
Vol 12 (4) ◽  
pp. 291-296
Author(s):  
J. Van Schuylenborgh

"Low humus podzols" do not possess a spodic horizon; podzol formation in conjunction with predominantly reducing conditions give rise to an eluviated profile. Low humus podzols have an umbric epipedon, the Fe and Al contents of the B horizon are intermediate between those of the A and C horizon, and their humus is mostly dispersed. Psammic Umbraquepts is proposed as a fifth subgroup for these soils. (Abstract retrieved from CAB Abstracts by CABI’s permission)


1969 ◽  
Vol 17 (4) ◽  
pp. 261-271
Author(s):  
J. Bouma ◽  
J. Van Schuylenborgh

The physical, chemical and micromorphological properties of a poorly drained soil profile developed on clayey parent material covered by a thin layer of loess are described. Clay skins on peds were absent in the B-horizon which is considered to be of Pleistocene age. In thin sections, however, oriented clay was observed inside peds occurring undisturbed as free grain and channel argillans, and disturbed by pedoturbation as quasicutans and papules. Clay was leached vertically through the B horizon along planar voids between prisms, leaving accumulations of skeleton grains. Some clay was also leached from the A2 horizon. Kaolinite was more mobile than illite or smectite. Reduction processes resulted in strongly bleached areas around prisms and in well developed mangans on ped faces and around channels. The profile was classified as an aerie glossaqualf. (Abstract retrieved from CAB Abstracts by CABI’s permission)


1965 ◽  
Vol 13 (3) ◽  
pp. 267-279
Author(s):  
J. Van Schuylenborgh ◽  
M.G.M. Bruggenwert

With the aid of parahydroxybenzoic acid as a model substance, some suggestions are given on the formation of the albic and spodic horizons under well-aerated conditions in very poor and acid parent materials. The acid forms soluble complexes with Fe, while insoluble compounds are formed with Al. The stability constants of the Fe complexes and the solubility product of the Al complex were determined. Hydrolysis of the Fe complexes formed in the A horizon, and formation of an insoluble Al complex are the most important mechanisms in the formation of the B2ir and B2h horizons, respectively. (Abstract retrieved from CAB Abstracts by CABI’s permission)


CATENA ◽  
2019 ◽  
Vol 183 ◽  
pp. 104234 ◽  
Author(s):  
Emerson Ferreira Vilela ◽  
Alberto Vasconcellos Inda ◽  
Yuri Lopes Zinn

Author(s):  
Л.И. Герасимова-Мейгал ◽  
И.М. Сиренев

Цель исследования - изучение особенностей восприимчивости пациентов с рассеянным склерозом (РС) к холодовому воздействию с помощью функциональных тестов, характеризующих функцию терморегуляции. Как известно, РС - хроническое прогрессирующее аутоиммунное заболевание центральной нервной системы мультифакториальной природы, более часто встречающееся в регионах с холодным и влажным климатом. Нарушения терморегуляции вследствие автономной дисфункции являются характерным признаком РС, вместе с тем участию холодового фактора в развитии заболевания не придается существенного значения. Методика. Обследовано 32 пациента (17 мужчин и 15 женщин, средний возраст 29,6 ± 4,2 года) с установленным диагнозом: РС ремиттирующе-рецидивирующая форма течения (средняя продолжительность заболевания - 4,2 ± 2,7 года) и 18 практически здоровых лиц группы сравнения. Восприятие холода оценивали с помощью визуально-аналоговой шкалы. Продолжительность холод-индуцированной вазоконстрикции после локального холодового теста изучали по данным инфракрасной термометрии. Вегетативную регуляцию вазомоторных реакций оценивали по результатам анализа вызванных кожных вегетативных потенциалов (ВКВП). Результаты. На основе анализа самооценки восприятия холода у пациентов с РС показана низкая переносимость холодового фактора. При проведении локального холодового теста отмечено замедление восстановления температуры кожи кисти, что характерно для усиления холод-индуцированной вазоконстрикции. В группе пациентов с РС выявлено снижение параметров ВКВП ладоней и стоп, свидетельствующее о дефиците нейрогенного контроля терморегуляционных сосудистых реакций. Заключение. У пациентов с РС выявлены нарушения механизмов терморегуляции при действии холода, что обусловливает высокую индивидуальную восприимчивость к холоду у данной категории лиц. Сопоставление результатов анализа механизмов индивидуальной холод-индуцированной реактивности у пациентов с РС с данными эпидемиологических исследований приводит к заключению о потенциальном модулирующем влиянии холодового фактора на течение РС. The purpose of the present study was focused on the evaluation of the sensitivity to cold in multiple sclerosis (MS) patients by means of functional thermoregulatory based tests. MS is known to be a chronic autoimmune progressive disease of the central nervous system of multifactor origin that is very common in regions with cold and humid climate. Disorder of thermoregulation caused by autonomic dysfunction is a typical feature of MS, however the role of the cold in the disease development is still underestimated. Methods. Thirty two MS patients (17 males, 15 females, mean age 29,6 ± 4,2 years) with the remittent form of the disease (mean disease duration 4,2 ± 2,7 years) and 18 age-matched healthy controls volunteered to participate in this study. Susceptibility to cold was analyzed with the use of visual-analogous scale. The duration of cold-induced vasoconstriction after local cold test was estimated using by infrared thermometry. Autonomic regulation of vasomotor reactions was investigated with the help of the skin sympathetic response (SSR) analysis. Results. The analysis of self-reported perception of the cold in MS patients showed their low tolerance to cold. Slow recovery of the skin temperature of the hand in the local cold test observed in MS patients was considered as the aggravated cold-induced vasoconstriction. The decreased SSR in the hands and feet in MS patients was found that indicates the deficit of the neurogenic control of thermoregulatory vasomotor reactions. Conclusion. The results obtained demonstrate the impairment of thermoregulation under cold in MS patients that leads to higher individual susceptibility to cold of this group. Comparing of the data found in this study on the mechanisms of the individual cold-induced reactivity in MS patients with epidemiological surveys enable to conclude that cold environment has potential modulating effect of on the course of MS.


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