SESQUIOXIDE-CEMENTED SOIL HORIZONS IN NORTHERN QUEBEC: THEIR DISTRIBUTION, PROPERTIES AND GENESIS

1976 ◽  
Vol 56 (4) ◽  
pp. 333-344 ◽  
Author(s):  
T. R. MOORE
Keyword(s):  
Organic Matter ◽  
Classification System ◽  
Soil Horizons ◽  
Amorphous Iron ◽  
Far North ◽  
Cemented Soil ◽  
North Shore ◽  
Iron Aluminum ◽  
Extractable Iron

Cemented subsoil horizons are observed in soils along the St. Lawrence North Shore, as far north as Esker. Cementation is mostly strongly developed at depths of 30–90 cm in freely drained soils of sand texture containing large amounts of amphibole minerals. The cemented horizons contain generally small quantities of extractable iron, aluminum and organic matter, though larger than their non-cemented counterparts. A slaking experiment indicates that amorphous iron and aluminum are the main cementing agents. Three hypotheses for the genesis of these cemented horizons are examined; it is proposed that iron and aluminum are released in the Ae horizon, translocated in a basically inorganic form, and precipitated in the B horizons as cementing agents. Study of a chronosequence of soils suggests that 5,000–6,000 yr are required for the formation of strong cementation. The new chemical criteria established for the Podzolic Order of the Canadian Classification System work well in these soils.

CONCENTRATIONS OF SOIL NUTRIENTS BEFORE AND AFTER FIRE

1970 ◽  
Vol 50 (1) ◽  
pp. 17-29 ◽  
Author(s):  
D. W. SMITH
Keyword(s):  
Organic Matter ◽  
Mineral Soil ◽  
Exchange Capacity ◽  
Adsorption Properties ◽  
Large Decrease ◽  
Northern Ontario ◽  
Sodium Potassium ◽  
Iron Aluminum ◽  
Before And After ◽  
Extractable Iron

Large amounts of nutrients from the L-H horizons and 0–2 cm of mineral soil were either redistributed at mineral soil depths or removed by leaching within a 15-month period after severe fire in jack pine barren lands in northern Ontario. Losses and redistribution by leaching were attributed to the large decrease in amount of organic matter (79 to 91%) and a decrease in exchange capacity of the L-H horizons as a result of burning. Increased solubility of the nutrients deposited in ash contributed to their vulnerability to leaching.Leaching of sodium, potassium and calcium was greatest during the first 3-month period after fire. Differential leaching resulted from the differing adsorption properties of the cations; more potassium was leached in comparison with calcium. Decreases in levels of extractable iron, aluminum and phosphorus may have been partly the result of their fixation in unavailable form, but leaching was responsible for 48% of the decrease in extractable phosphorus from the surface horizons over the 15-month period.

scholarly journals Comparison of Total Nitrogen Methods Applied for Histosols and Soil Horizons with High Organic Matter Content

2006 ◽  
Vol 37 (7-8) ◽  
pp. 939-943 ◽  
Author(s):  
Marcos Gervasio Pereira ◽  
Ademar Espindula ◽  
Gustavo Souza Valladares ◽  
Lúcia Helena Cunha dos Anjos ◽  
Vinícius de Melo Benites ◽  
...  
Keyword(s):  
Organic Matter ◽  
Total Nitrogen ◽  
Organic Matter Content ◽  
Matter Content ◽  
Soil Horizons ◽  
High Organic Matter Content ◽  
High Organic Matter

A LABORATORY STUDY OF GLEYING

1965 ◽  
Vol 45 (2) ◽  
pp. 199-206 ◽  
Author(s):  
J. A. McKeague
Keyword(s):  
Organic Matter ◽  
Acetic Acid ◽  
Room Temperature ◽  
Rate Of Change ◽  
Redox Potentials ◽  
Soil Columns ◽  
Flooded Soils ◽  
Soil Material ◽  
Effects Of Temperature ◽  
Extractable Iron

Columns of different soil materials with ground leaves at the surface were maintained for 18 months with the water table continuously above the surface, or fluctuating between the surface and 15 cm. Redox potentials, colors, and extractable iron were determined. The effects of temperature and of organic matter on the rate of change of Eh were studied with flooded soils in test tubes.The rate and degree of development of dull colors and mottling in the soil columns was influenced greatly by the nature of the soil material. Reduction effected marked increases in acetic acid extractable iron from all of the soil materials. Low redox potentials developed rapidly at room temperature in flooded soils containing appreciable amounts of organic matter. Eh values below 0 mv developed slowly in soils at 1 °C and at room temperature in some soils that were almost devoid of organic matter. Release of Fe+2 from ferrous minerals was thought to account for these low Eh values.

Soil microorganisms and the formation of proteoid roots

1974 ◽  
Vol 22 (4) ◽  
pp. 681 ◽  
Author(s):  
BB Lamont ◽  
AJ Mccomb
Keyword(s):  
Organic Matter ◽  
Soil Microorganisms ◽  
Surface Soil ◽  
Chemical Components ◽  
Soil Horizons ◽  
Sterile Soil ◽  
Proteoid Roots ◽  
Water Extracts ◽  
High Organic Matter ◽  
Microbial Numbers

Proteoid roots are not formed in sterile soil under conditions which would otherwise allow their production. This is attributed to the absence of soil microorganisms rather than to an alteration of chemical components by autoclaving. Water extracts from proteoid roots or their associated soil did not enhance the formation of proteoid roots. High microbial numbers in the surface soil horizons are considered largely responsible for the abundance of proteoid roots in these high organic matter regions. Results of experiments indicate that the formation of proteoid roots is stimulated by soil microorganisms which themselves do not invade the parent root, though the relevant organisms have yet to be identified.

IRON-MANGANESE AND OTHER PANS IN SOME SOILS OF NEWFOUNDLAND

1968 ◽  
Vol 48 (3) ◽  
pp. 243-253 ◽  
Author(s):  
J. A. McKeague ◽  
A. W. H. Damman ◽  
P. K. Heringa
Keyword(s):  
Organic Matter ◽  
Classification System ◽  
Soil Classification ◽  
Soil Mapping ◽  
Organic Soils ◽  
Hydrous Oxides ◽  
Organic Complexes ◽  
Black Layer ◽  
Mineral Soils ◽  
Iron Manganese

The thin, dark-colored, cemented layers that occur commonly in coarse deposits under peat in humid coastal areas of Newfoundland were found to be cemented mainly by amorphous Fe and Mn or by Fe compounds. The Mn contents of these pans varied from about 0.1 to 15%, and Mn tended to accumulate in the lower part of the pan. The Fe-Mo pans could be distinguished in the field from Fe or Fe-organic matter pans by the fact that the black layer at the base of the Fe-Mn pans reacted vigorously with cold 3% H2O2. The Fe-organic pans, which usually had a rusty brown layer at the base, reacted only slowly. The Fe-Mn pans were associated generally with more humid conditions, as indicated by a greater thickness of peat, than those characteristic of the Fe-organic matter pans. We think that reduction, translocation as Fe+2 and Mn+2 and subsequent oxidation and precipitation of mixed hydrous oxides must be involved in the formation of the Fe-Mn pans, whereas translocation and precipitation of Fe-organic complexes are thought to be involved in the formation of Fe-organic matter pans.Many of the Fe-Mn pans occur below organic soils, but they also occur within the sola of some mineral soils. Thus, they should be recognized in soil mapping and accommodated in the soil classification system.

scholarly journals Bulk Density Prediction for Histosols and Soil Horizons with High Organic Matter Content

2017 ◽  
Vol 41 (0) ◽  
Author(s):  
Sidinei Julio Beutler ◽  
Marcos Gervasio Pereira ◽  
Wagner de Souza Tassinari ◽  
Michele Duarte de Menezes ◽  
Gustavo Souza Valladares ◽  
...  
Keyword(s):  
Organic Matter ◽  
Bulk Density ◽  
Organic Matter Content ◽  
Matter Content ◽  
Soil Horizons ◽  
High Organic Matter Content ◽  
Density Prediction ◽  
High Organic Matter
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