scholarly journals INFLUENCE OF DRAINAGE REGIME ON THE CHEMISTRY AND MORPHOLOGY OF SOME MANITOBA SOILS: SANDY CHERNOZEMIC AND GLEYSOLIC SOILS OF THE LOWER ASSINIBOINE DELTA

1984 ◽  
Vol 64 (4) ◽  
pp. 587-604 ◽  
Author(s):  
W. MICHALYNA ◽  
R. H. RUST
Keyword(s):  
Redox Potential ◽  
Soil Temperature ◽  
Early Summer ◽  
Near Surface ◽  
Groundwater Levels ◽  
Reducing Conditions ◽  
Exchangeable Ca ◽  
Morphological Criteria ◽  
Water Tables

A number of imperfectly and poorly drained sandy soils from the Almasippi Association of the Lower Assiniboine Delta in Manitoba, traditionally classified as Gleyed Chernozems and Gleysols, were characterized by morhological descriptions, chemical and physical analyses. Soil temperature, groundwater levels, and redox potential of both soil and water were determined at selected sites for various periods to a maximum of 2 years. The upper 30 cm of the soils, traditionally considered as Gleysols, had undergone strong reducing conditions (100 to −200 mV) for at least 2 mo in the spring and early summer; these areas were covered with hydrophytic vegetation and remained saturated at or near surface to July. The subsoil below 45 cm remained in an oxidized state throughout the year. Exchangeable Ca/Mg ratio was near unity in the Gleysols and substantially greater in the Gleyed subgroups. Oxalate to dithionite-extractable iron ratios were greater than 0.45 in the lower part and below the solum of Gleysolic and Gleyed soils. In soils classified as Gleyed subgroups, water tables were below 1.3 m throughout the season and soil profiles were in an oxidized condition. Classification of these soils according to the present Canadian and U.S. system would require a change in concept and approach from the traditional view of Gleysolic soils in Canada. Key words: Redox potential, chemical criteria, morphological criteria, water table, soil temperature

INFLUENCE OF DRAINAGE REGIME ON THE CHEMISTRY AND MORPHOLOGY OF SOME MANITOBA SOILS: CLAYEY CHERNOZEMIC AND GLEYSOLIC SOILS OF THE RED RIVER PLAIN

1984 ◽  
Vol 64 (4) ◽  
pp. 605-620 ◽  
Author(s):  
W. MICHALYNA ◽  
R. H. RUST
Keyword(s):  
Redox Potential ◽  
Red River ◽  
Morphological Description ◽  
Redox Potentials ◽  
Groundwater Levels ◽  
Exchangeable Ca ◽  
Morphological Criteria ◽  
River Plain ◽  
Extractable Iron

A number of clayey soils of the Red River-Osborne Association that developed under imperfectly to poorly drained conditions on the Red River Plain in Manitoba were studied. These soils, traditionally classified as Gleyed Chernozemic soils and Gleysolic, were characterized by morphological description, chemical and physical analyses. Most of the areas of the Red River Plain are cultivated and have had considerable improvement of surface drainage. Redox potentials, groundwater level and redox potential in the groundwater were determined at selected sites for various periods to a maximum of 2 years. Soils traditionally classified as Gleysols had shallow sola, minimal grumic features, and low chromas and mottles that would meet with present criteria; exchangeable Ca/Mg ratios were commonly near unity in the lower part of the solum. These soils were in an oxidized condition with Ept above 550 mV in the profiles; groundwater levels were below 1.4 m. Oxalate to dithionite extractable iron ratios were greater than 0.45 in the lower part of the solum on the Gleysols and those Gleyed Chernozemic soils with chromas of 2 or less with mottles. Gleyed Chernozemic soils with chromas of 2 or less with mottles would key as Gleysols using the present Canadian criteria; this would result in a change of traditional concepts. Classification of these soils according to the Canadian (taxon) and the U.S. systems are discussed. Key words: Chemical criteria, morphological criteria, water table, soil temperature, redox potential

EVALUATION OF CRITERIA FOR THE CLASSIFICATION OF GLEYSOLIC SOILS IN SASKATCHEWAN

1989 ◽  
Vol 69 (1) ◽  
pp. 153-164 ◽  
Author(s):  
J. J. MILLER ◽  
D. F. ACTON ◽  
R. J. ST. ARNAUD
Keyword(s):  
Soil Temperature ◽  
Water Table ◽  
Seasonal Changes ◽  
Soil Surface ◽  
Redox Status ◽  
Hydrophytic Vegetation ◽  
Soil Zone ◽  
Morphological Criteria ◽  
Lower Slope

Six soils within and adjacent to two willow-ring depressions in hummocky moraine of the Dark Brown soil zone were monitored for seasonal changes in water table levels, redox status, and soil temperature to evaluate color citeria for identifying saturated and reduced soils of the Gleysolic order. Soils in the center of the willow-ring depressions had water table levels close to the soil surface, Ept values of < 100 mV, and were covered by hydrophytic vegetation. Soils near the perimeter of the willow-ring depression had water table levels generally below 1 m, Ept values > 400 mV, and were covered by hydrophytic vegetation. Three of the depressional soils had matrix chromas of 1 in the Ae and/or Bt (Btj) horizons, with prominent rusty mottles, and met the color criteria of Humic Luvic Gleysols. The fourth depressional soil had matrix chromas of 1 in the Btj horizon, but no mottles were present within 50 cm of the soil surface, and met the color criteria of an Orthic Humic Gleysol. Two nondepressional soils, on lower slope positions just outside the willow-ring depressions, exhibited water table levels generally below 1.5 m, had an Ept of > 400 mV, and lacked hydrophytic vegetation. Of these, one soil had matrix chromas of 2 and prominent rusty mottles within 50 cm of the soil surface and met the color criteria of a Rego Humic Gleysol. The other had mottles of low chroma within 1 m of the surface and met the color criteria of a Gleyed Rego Dark Brown. Based on this study, the color criteria are adequate for depressional soils but are inadequate for the classification of soils beyond the willow-ring. Key words: Water table level, redox potential, soil temperature, morphological criteria, gleying

scholarly journals Relationships of Hydrological Seasons in Rivers and Groundwaters in Selected Catchments in Poland

Water ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 250
Author(s):  
Przemysław Tomalski ◽  
Edmund Tomaszewski ◽  
Dariusz Wrzesiński ◽  
Leszek Sobkowiak
Keyword(s):  
River Flow ◽  
Geographical Location ◽  
Base Flow ◽  
Water Shortages ◽  
Groundwater Levels ◽  
Average Value ◽  
Geographical Regions ◽  
New Variables ◽  
Mixed Types

The study applied the method of hydrological season identification in a time series of river total and base flows and in groundwater levels. The analysis covered a series of daily measurements from the period 2008–2017 in nine catchments located in different geographical regions of Poland. The basis of the classification of hydrological seasons, previously applied for river discharges only, was the transformation of the original variables into a series reflecting three statistical features estimated for single-name days of a year from a multiyear: average value, variation coefficient, and autocorrelation coefficient. New variables were standardized and after hierarchical clustering, every day of a year had a defined type, valorizing three features which refer to quantity, variability, and the stochastic nature of total and base river flow as well as groundwater stage. Finally, sequences of days were grouped into basic (homogenous) seasons of different types and transitional seasons including mixed types of days. Analysis indicated determinants of types, length, and frequency of identified hydrological seasons especially related to river regime, hydrogeological and hydrometeorological conditions as well as physiographical background were directly influenced by geographical location. Analysis of the co-occurrence of the same types of hydrological seasons allowed, in some catchments, periods of synchronic alimentation (groundwater and base flow, mainly in the cold half-year) and water shortages (all three components, mainly in the warm half-year) to be identified.

Cover crop effects on soil temperature in a clay loam soil in southwestern Ontario

2021 ◽  
pp. 1-10
Author(s):  
X.M. Yang ◽  
W.D. Reynolds ◽  
C.F. Drury ◽  
M.D. Reeb
Keyword(s):  
Soil Temperature ◽  
Cover Crops ◽  
Environmental Performance ◽  
Cover Crop ◽  
Crop Production ◽  
Surface Soil ◽  
Clay Loam ◽  
Near Surface ◽  
Soil Temperatures ◽  
Surface Soil Temperature

Although it is well established that soil temperature has substantial effects on the agri-environmental performance of crop production, little is known of soil temperatures under living cover crops. Consequently, soil temperatures under a crimson clover and white clover mix, hairy vetch, and red clover were measured for a cool, humid Brookston clay loam under a corn–soybean–winter wheat/cover crop rotation. Measurements were collected from August (after cover crop seeding) to the following May (before cover crop termination) at 15, 30, 45, and 60 cm depths during 2018–2019 and 2019–2020. Average soil temperatures (August–May) were not affected by cover crop species at any depth, or by air temperature at 60 cm depth. During winter, soil temperatures at 15, 30, and 45 cm depths were greater under cover crops than under a no cover crop control (CK), with maximum increase occurring at 15 cm on 31 January 2019 (2.5–5.7 °C) and on 23 January 2020 (0.8–1.9 °C). In spring, soil temperatures under standing cover crops were cooler than the CK by 0.1–3.0 °C at 15 cm depth, by 0–2.4 °C at the 30 and 45 cm depths, and by 0–1.8 °C at 60 cm depth. In addition, springtime soil temperature at 15 cm depth decreased by about 0.24 °C for every 1 Mg·ha−1 increase in live cover crop biomass. Relative to bare soil, cover crops increased near-surface soil temperature during winter but decreased near-surface soil temperature during spring. These temperature changes may have both positive and negative effects on the agri-environmental performance of crop production.

scholarly journals Seasonal dynamics of methane emissions from a subarctic fen in the Hudson Bay Lowlands

2013 ◽  
Vol 10 (7) ◽  
pp. 4465-4479 ◽  
Author(s):  
K. L. Hanis ◽  
M. Tenuta ◽  
B. D. Amiro ◽  
T. N. Papakyriakou
Keyword(s):  
Soil Temperature ◽  
Air Temperature ◽  
Growing Season ◽  
Near Surface ◽  
Growing Seasons ◽  
Air Temperatures ◽  
Soil Temperatures ◽  
Surface Soil Temperature ◽  
Filling Method ◽  
Highly Correlated

Abstract. Ecosystem-scale methane (CH4) flux (FCH4) over a subarctic fen at Churchill, Manitoba, Canada was measured to understand the magnitude of emissions during spring and fall shoulder seasons, and the growing season in relation to physical and biological conditions. FCH4 was measured using eddy covariance with a closed-path analyser in four years (2008–2011). Cumulative measured annual FCH4 (shoulder plus growing seasons) ranged from 3.0 to 9.6 g CH4 m−2 yr−1 among the four study years, with a mean of 6.5 to 7.1 g CH4 m−2 yr−1 depending upon gap-filling method. Soil temperatures to depths of 50 cm and air temperature were highly correlated with FCH4, with near-surface soil temperature at 5 cm most correlated across spring, fall, and the shoulder and growing seasons. The response of FCH4 to soil temperature at the 5 cm depth and air temperature was more than double in spring to that of fall. Emission episodes were generally not observed during spring thaw. Growing season emissions also depended upon soil and air temperatures but the water table also exerted influence, with FCH4 highest when water was 2–13 cm below and lowest when it was at or above the mean peat surface.

scholarly journals Quantification of the effect of modeled lightning NO<sub>2</sub> on UV–visible air mass factors

2017 ◽  
Vol 10 (11) ◽  
pp. 4403-4419 ◽  
Author(s):  
Joshua L. Laughner ◽  
Ronald C. Cohen
Keyword(s):  
United States ◽  
A Priori ◽  
Early Summer ◽  
Lightning Flash ◽  
Eastern United States ◽  
Ozone Monitoring Instrument ◽  
Reanalysis Dataset ◽  
Near Surface ◽  
Air Mass ◽  
Convective Clouds

Abstract. Space-borne measurements of tropospheric nitrogen dioxide (NO2) columns are up to 10x more sensitive to upper tropospheric (UT) NO2 than near-surface NO2 over low-reflectivity surfaces. Here, we quantify the effect of adding simulated lightning NO2 to the a priori profiles for NO2 observations from the Ozone Monitoring Instrument (OMI) using modeled NO2 profiles from the Weather Research and Forecasting–Chemistry (WRF-Chem) model. With observed NO2 profiles from the Deep Convective Clouds and Chemistry (DC3) aircraft campaign as observational truth, we quantify the bias in the NO2 column that occurs when lightning NO2 is not accounted for in the a priori profiles. Focusing on late spring and early summer in the central and eastern United States, we find that a simulation without lightning NO2 underestimates the air mass factor (AMF) by 25 % on average for common summer OMI viewing geometry and 35 % for viewing geometries that will be encountered by geostationary satellites. Using a simulation with 500 to 665 mol NO flash−1 produces good agreement with observed NO2 profiles and reduces the bias in the AMF to  <  ±4 % for OMI viewing geometries. The bias is regionally dependent, with the strongest effects in the southeast United States (up to 80 %) and negligible effects in the central US. We also find that constraining WRF meteorology to a reanalysis dataset reduces lightning flash counts by a factor of 2 compared to an unconstrained run, most likely due to changes in the simulated water vapor profile.

Geochemical Behaviour of Uranium in Sedimentary Formations: Insights From a Natural Analogue Study

2009 ◽  
Author(s):  
Ulrich Noseck ◽  
Vaclava Havlova ◽  
Juhani Suksi ◽  
Thomas Brasser ◽  
Radek Cervinka
Keyword(s):  
Current Knowledge ◽  
Natural Analogue ◽  
Near Surface ◽  
Co2 Partial Pressure ◽  
Long Term Stability ◽  
Reducing Conditions ◽  
Phosphate Mineral ◽  
Sedimentary System ◽  
The Impact

Groundwater data from the natural analogue site Ruprechtov have been evaluated with special emphasis on the uranium behaviour in the so-called uranium-rich clay/lignite horizon. In this horizon in-situ Eh-values in the range of −160 to −280 mV seem to be determined by the SO42−/HS− couple. Under these conditions U(IV) is expected to be the preferential redox state in solution. However, on-site measurements in groundwater from the clay/lignite horizon show only a fraction of about 20% occurring in the reduced state U(IV). Thermodynamic calculations reveal that the high CO2 partial pressure in the clay/lignite horizon can stabilise hexavalent uranium, which explains the occurrence of U(VI). The calculations also indicate that the low uranium concentrations in the range between 0.2 and 2.1μg/l are controlled by amorphous UO2 and/or the U(IV) phosphate mineral ningyoite. This confirms the findings from previous work that the uranium (IV) mineral phases are long-term stable under the reducing conditions in the clay/lignite horizon without any signatures for uranium mobilisation. It supports the current knowledge of the geological development of the site and is also another important indication for the long-term stability of the sedimentary system itself, namely of the reducing geochemical conditions in the near-surface (30m to 60 m deep) clay/lignite horizon. Further work with respect to the impact of changes in redox conditions on the uranium speciation is on the way.

EXISTING AND POSSIBLE NEW GLEYSOLIC ORDER CRITERIA APPLIED TO FIVE PEDONS FROM BRITISH COLUMBIA

1986 ◽  
Vol 66 (2) ◽  
pp. 323-336 ◽  
Author(s):  
J. A. McKEAGUE ◽  
C. TARNOCAI ◽  
H. A. LUTTMERDING
Keyword(s):  
British Columbia ◽  
Thin Sections ◽  
Soil Water Regime ◽  
Reducing Conditions ◽  
Current Classification ◽  
Bulk Chemical ◽  
Iron Manganese ◽  
Iron And Manganese ◽  
Do So

Use of the current criteria for distinguishing Gleysolic soils from gleyed intergrades to other soil classes resulted in the apparent misclassification of some soils in British Columbia. Pedologists of the area selected five pedons encompassing several degrees of expression of gley features. Current classification criteria based on soil color and possible new differentiating features based on chemical and micromorphological analyses were applied in considering the classification of the soils. Application of the current specific color criteria involving low chromas and prominent mottling result in the classification of three pedons in the Gleysolic order and two in gleyed subgroups of other orders. This classification was appropriate in the view of B.C. pedologists except for one Gleysolic pedon in which the water table is rarely within 1 m of the surface. Prior to drainage, however, the soil was probably saturated to the surface and under reducing conditions for prolonged periods each year. Thus, classification as a Gleysolic soil is appropriate as it probably reflects the prevailing conditions and processes during most of the period of soil genesis.Segregation of iron and manganese as nodules and coatings was most marked in the Gleysolic pedons. Walls of some voids were bleached due to depletion of iron oxides. Though study of thin sections, bulk chemical analysis and analysis of specific features by scanning electron microscopy-energy dispersive X-ray analysis (SEM-EDXRA) were useful in providing information on soil properties, they did not indicate an improved basis for differentiating Gleysolic soils from others. The color criteria used to distinguish soils of the Gleysolic order do not necessarily reflect the current soil water regime, and they are not intended to do so. The current criteria resulted in the appropriate classification of the five soils. Key words: Gleying, reduction, iron, manganese, micromorphology, SEM-EDXRA

The influence of rotation, tillage and row spacing on near-surface soil temperature for winter wheat in southern Alberta

2003 ◽  
Vol 83 (1) ◽  
pp. 89-98 ◽  
Author(s):  
F. J. Larney ◽  
T. Ren ◽  
S. M. McGinn ◽  
C. W. Lindwall ◽  
R. C. Izaurralde
Keyword(s):  
Winter Wheat ◽  
Soil Temperature ◽  
Management Practices ◽  
Spacing Effect ◽  
Triticum Aestivum L ◽  
Conventional Tillage ◽  
Row Spacing ◽  
Near Surface ◽  
Soil Temperatures ◽  
Surface Soil Temperature

Soil and crop management practices and their effects on surface residue levels can modify soil temperature. Our study investigated the effect of rotation, tillage and row spacing on near-surface (0.025 m) soil temperature under winter wheat (Triticum aestivum L.) in 1993-1994 and 1994-1995. The main treatment was winter wheat rotation: continuous winter wheat (WW); winter wheat-canola (Brassica campestris L.) (WC) or winter wheat-fallow (WF)] with tillage sub-treatments of conventional tillage (CT) vs. zero tillage (ZT) and row spacing treatments of uniform row (UR) vs. paired row (PR) spacing. From fall 1993 to spring 1994, ZT was cooler than CT by 1.2°C on the WC rotation, 1.1°C on WW and 0.4°C on the WF rotation. From fall 1994 to spring 1995, the magnitude of tillage differences was lower on all three rotations with ZT being cooler than CT by 0.1–0.9°C. The magnitude of the row spacing effect on soil temperature was less than that of the tillage effect. Extreme differences in soil temperature due to tillage were generally higher (1.0–4.9°C) on the WW and WC than the WF rotation (0.6–2.5°C) due to the presence of more crop residue. Results demonstrate that while ZT promotes overall cooler soils under winter wheat from fall to late spring, especially on continuously cropped (WW, WC) rotations, it also allows moderation of soil temperatures during extremely cold periods. Key words: Soil temperature, winter wheat, rotation, tillage, row spacing

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