Solubilité de l'or dans les eaux interstitielles de la latérite coiffant le gîte aurifère de Misséni, au Mali

1993 ◽  
Vol 30 (8) ◽  
pp. 1553-1565 ◽  
Author(s):  
Frédéric Séa ◽  
Marc G. Tanguay ◽  
Pierre Trudel ◽  
Mario Bergeron
Keyword(s):  
Organic Matter ◽  
Humic Acid ◽  
Organic Carbon ◽  
Humic Acids ◽  
Chloride Ion ◽  
High Solubility ◽  
Gold Solubility ◽  
Mn Oxides ◽  
Very High ◽  
Interstitial Waters

Twenty samples of interstitial waters and pressed saprolite were collected within undisturbed saprolite blocks to determine the actual gold transporting mode in the auriferous laterites of Misséni, Mali. The results of the analyses indicate a very high solubility of gold in the interstitial waters of the Misséni laterites (from <2 to 16.7 ppb Au; Eh, 0.356–0.419 V; pH, 6.7–7.7). The calculated theoretical concentrations of auric chloride ion, [Formula: see text], (0.3 × 10−14 – 32.7 × 10−4 ppm) and thiosulphate ion, [Formula: see text], (2.5 × 10−212 – 6.7 × 10−180 ppm), which are generally inferred to be the ions transporting the gold in a supergene environment, are insignificant in the interstitial waters of the Misséni saprolite. Given the absence of significant concentrations of chloride or thiosulphate ions as measured in the interstitial waters of Misséni (Cl−, 1.5 × 10−4 – 1.2 × 10−2 mol L−1; [Formula: see text], 1.1 × 10−111 – 4.2 × 10−95 mol L−1), the gold monohydroxide, AuOH(H2O)0, could be responsible for the gold mobilization in the studied saprolite. However, its transport could be limited by the conspicuous (Fe, Mn) oxides in the Misséni saprolite, which can act as adsorbents. The calculated concentrtion of humic acid (0.004–0.03%), which can solubilize the gold contained in the analyzed interstitial waters, is 2 to 4 times lower than that of the measured organic matter in the samples of pressed saprolite (from <0.016 to 0.07% in organic carbon). These latter results could indicate that a part of the gold solubility in the Misséni superficial saprolite is linked to the humic acids. [Journal Translation]

CHARACTERISTICS OF ORGANIC MATTER IN DEGRADING CHERNOZEMIC SURFACE SOILS

1963 ◽  
Vol 43 (2) ◽  
pp. 275-286 ◽  
Author(s):  
C. D. Sawyer ◽  
S. Pawluk
Keyword(s):  
Organic Matter ◽  
Humic Acid ◽  
Organic Carbon ◽  
Humic Acids ◽  
Acid Content ◽  
Organic Carbon Content ◽  
Total Acidity ◽  
Organic Fraction ◽  
Organic Debris ◽  
Organic Fractions

Humic acids, polysaccharides, and polyuronides were extracted from samples representative of the organic and mineral A horizons of two Dark Grey Wooded soils. These organic fractions were characterized in order to determine the alterations, if any, which may be evident in some of the organic constituents present at varying depths in the organic and mineral A horizons as a result of progressive podzolic degradation.Humic acid content in the organic fraction was found to decrease with depth in the mineral A horizon. Methoxyl content of the purified humic acids averaged 0.26 me./g. and decreased with depth while the total acidity (phenolic and carboxyl acidity) averaged 7.6 me./g. and increased with depth. Nitrogen content of the purified humic acids averaged 2.6 per cent and was relatively constant throughout the organic and mineral A horizons. The humic acid content of the undecomposed and semi-decomposed organic debris was found to be only slightly lower than that of the Ah horizon. This was probably at least partially due to hydrolyses of organic matter during the harsh extraction of humic acids with warm 1.0 N NaOH.Total polysaccharide and polyuronide content of these soils decreased rapidly with depth; however, this decrease paralleled the decrease in total organic carbon content.

scholarly journals Properties of Humic Acids in Meadow Soils Irrigated With the Slope-And Flooding System

2021 ◽  
Author(s):  
Magdalena Banach-Szott ◽  
Andrzej Dziamski
Keyword(s):  
Particle Size ◽  
Organic Matter ◽  
Organic Carbon ◽  
Humic Acids ◽  
Soil Samples ◽  
Hydrophobic Properties ◽  
Irrigation Ditch ◽  
Ft Ir ◽  
Degree Of Maturity

Abstract The aim of the research has been to determine the effect of many-year irrigation of unique grasslands on the properties of humic acids defining the quality of organic matter. The research was performed based on the soil (Albic Brunic Arenosol, the A, AE and Bsv horizons) sampled from Europe’s unique complex of permanent grasslands irrigated continuously for 150 years, applying the slope-and-flooding system; the Czerskie Meadows. The soil samples were assayed for the content of total organic carbon (TOC) and the particle size distribution. HAs were extracted with the Schnitzer method and analysed for the elemental composition, spectrometric parameters in the UV-VIS range, hydrophilic and hydrophobic properties and the infrared spectra were produced. The research results have shown that the HAs properties depended on the depth and the distance from the irrigation ditch. The HAs of the A horizon of the soils were identified with a lower “degree of maturity”, as reflected by the values of atomic ratios (H/C, O/C, O/H), absorbance coefficients, and the FT-IR spectra, as compared with the HAs of the Bsv horizon. The HAs molecules of the soils sampled furthest from the irrigation ditch were identified with a higher degree of humification, as compared with the HAs of the soils sampled within the closest distance. The results have demonstrated that many-year grassland irrigation affected the structure and the properties of humic acids.

Soil organic matter in soils of the Russian Arctic: insights from 13C-NMR spectroscopy

2020 ◽  
Author(s):  
Ivan Alekseev ◽  
Evgeny Abakumov
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Organic Carbon ◽  
Humic Acids ◽  
13C Nmr ◽  
Cold Climate ◽  
Molecular Organization ◽  
Cold Temperatures ◽  
Organic Matter Stabilization ◽  
Global Carbon

&lt;p&gt;Polar soils play a key role in global carbon circulation and stabilization as they contain maximum stocks of soil organic matter (SOM) within the whole pedosphere. Cold climate and active layer dynamics result in the stabilization of essential amounts of organic matter in soils, biosediments, and grounds of the polar biome. Chemical composition of soil organic carbon (SOC) determines its decomposability and may affect soil organic matter stabilization (SOM) rate (Beyer, 1995). This is quite important for understanding variability in SOC pools and stabilization rate in context of changes in plant cover or climate (Rossi et al. 2016). &lt;sup&gt;13&lt;/sup&gt;C nuclear magnetic resonance spectroscopy, which provides detailed information on diversity of structural composition of humic acids and SOM, may also be used to study the SOM dynamics under decomposition and humification proceses (Kogel-Knabner, 1997; Zech et al., 1997). This study aims to characterize molecular organization of the humic acids, isolated from various permafrost-affected soils of Yamal region and to assess the potential vulnerability of soils organic matter in context of possible mineralization processes. Organic carbon stocks for studied area were 7.85 &amp;#177; 2.24 kg m-2 (for 0-10 cm layer), 14.97 &amp;#177; 5.53 kg m-2 (for 0-30 cm), 23.99 &amp;#177; 8.00 kg m-2 (for 0-100 cm). Results of solid-state 13C-NMR spectrometry showed low amounts of aromatic components in studied soils. All studied humic powders are characterized by predominance of aliphatic structures, and also carbohydrates, polysaccharides, ethers and amino acids. High content of aliphatic fragments in studied humic acids shows their similarity fulvic acids. Low level of aromaticity reflects the accumulation in soil of lowly decomposed organic matter due to cold temperatures. Our results provide further evidence of high vulnerability and sensitivity of permafrost-affected soils organic matter to Arctic warming. Consequently, these soils may play a crucial role in global carbon balance under effects of climate warming.&lt;/p&gt;

EFFECT OF LONG-TERM PIG SLURRY AND SOLID CATTLE MANURE APPLICATION ON SOIL CHEMICAL AND BIOLOGICAL PROPERTIES

1989 ◽  
Vol 69 (1) ◽  
pp. 39-47 ◽  
Author(s):  
A. NDAYEGAMIYE ◽  
D. CÔTÉ
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Microbial Activity ◽  
Humic Acids ◽  
Organic Matter Content ◽  
Biological Properties ◽  
Matter Content ◽  
Cattle Manure ◽  
Pig Slurry

Chemical and biological properties were evaluated in 1987 on an acidic silty loam soil following a long-term field study established in 1978 and cultivated with silage corn. Treatments included a control, solid cattle manure (20, 40 and 60 Mg ha−1 FYM) and pig slurry (60, 120 m3 ha−1 SLU) applied every 2 yr and annually, respectively. No fertilizer was applied. The results of this study have shown that neither treatment significantly affected soil pH values, total-N contents and C:N ratios compared to the control. The cation exchange capacity (CEC) of the soil was significantly higher with FYM treatment than with control or SLU application. The highest rates of FYM and SLU have also increased (P < 0.05) soil organic carbon, microbial activity and potentially mineralizable nitrogen. The soil microflora populations (bacteria, fungi, actinomycetes, ammonifiers and nitrifiers) were greatly improved by both treatments. There were no significant differences in organic matter content or the relative amount of humic and fulvic acids between FYM and SLU plots. In spite of these results, FYM application (40 and 60 Mg ha−1) did affect more significantly the distribution of organic carbon in HA and the E4/E6 quotients than SLU additions. Humic acids extracted from SLU amended soils had a lower C content and lower E4/E6 ratios than humic acids from FYM soils. Long-term SLU application did not contribute to decreased organic matter content, CEC and humic acids yield, probably because of optimal organic residues returned to the soil by the corn crops. The FYM application generally improved soil chemical and biological properties. For a sustainable soil productivity, long-term SLU application should then be avoided in rotation in which small amounts of plant residues are returned, especially on soils with low organic matter contents. Key words: Organic matter, microbial activity, nitrogen mineralization potential, CEC, solid cattle manure, pig slurry

scholarly journals Properties of Humic Acids in Meadow Soils Irrigated with the Slope-and-Flooding System

Agronomy ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 2553
Author(s):  
Magdalena Banach-Szott ◽  
Andrzej Dziamski ◽  
Maciej Markiewicz
Keyword(s):  
Organic Matter ◽  
Carbon Sequestration ◽  
Soil Organic Matter ◽  
Organic Carbon ◽  
Humic Acids ◽  
Infrared Spectra ◽  
Soil Protection ◽  
Mean Values ◽  
Irrigation Ditch ◽  
The Mean

The still-advancing soil degradation and the related losses of soil organic carbon stocks due to the limited inflow of organic residues in agro-ecosystems encourage more and more soil protection. Establishing meadow ecosystems is one of the key methods of agricultural land use preventing losses of organic carbon in soils. Based on the research on the properties of humic acids, it is possible to determine the advancement of the processes of transformation and decomposition of soil organic matter. The obtained results may allow for the development of a soil protection strategy and more effective sequestration of organic carbon. Therefore, the aim of the research was to determine the properties of humic acids defining the quality of organic matter of meadow soils irrigated for 150 years with the slope-and-flooding system. The research was performed based on the soils (Albic Brunic Arenosol) sampled from Europe’s unique complex of permanent irrigated grasslands (the same irrigation management for 150 years), applying the slope-and-flooding system: the Czerskie Meadows. The soil samples were assayed for the content of total organic carbon (TOC) and the particle size distribution. HAs were extracted with the Schnitzer method and analysed for the elemental composition, spectrometric parameters in the UV-VIS (ultraviolet-visible) range, hydrophilic and hydrophobic properties and the infrared spectra. The research results showed that the HAs properties depend on the depth and the distance from the irrigation ditch. The HAs of soils sampled from the depth of 0–10 cm were identified with a lower “degree of maturity” as compared with the HAs of soils sampled from the depth of 20–30 cm, reflected by the values of atomic ratios (H/C, O/C, O/H), absorbance coefficients, and the FT-IR (Fourier transform infrared) spectra. The mean values of the H/C ratio in the HAs molecules of soils sampled from the depth of 20–30 cm were lower by 8.2% than those from the depth of 0–10 cm. The mean values of the absorbance coefficient A4/6 in the HAs molecules of soils sampled from the depth of 20–30 cm were lower by 9.6% than in the HAs molecules of soils sampled from the depth of 0–10 cm. The HAs molecules of the soils sampled 25 m from the irrigation ditch were identified with a higher degree of humification, as compared with the HAs of the soils sampled 5 m from the irrigation ditch. The results identified that humic acids produced in the many-year irrigated sandy soils were identified with a high degree of humification, which proves the relative stability of the soil’s organic matter. It confirms the importance of meadow soils for the carbon sequestration process. It should also be emphasized that the research area is interesting, although hardly described in terms of organic matter properties. Further and more detailed applicable research is planned, e.g., monitoring of total organic carbon content and comparing the properties of irrigated and non-irrigated meadow soils. Continuity of research is necessary to assess the direction of the soil organic matter transformation in such a unique ecosystem. The obtained results may allow for the development of, inter alia, models of agricultural practices that increase carbon sequestration in soils. In the long term, this will allow for greater environmental benefits and, thus, also increased financial benefits.

THE PEDOGENETIC ORIGIN AND CHARACTERISTICS OF ORGANIC MATTER OF SOLOD SOILS

1979 ◽  
Vol 59 (4) ◽  
pp. 357-362 ◽  
Author(s):  
D. W. ANDERSON ◽  
E. DE JONG ◽  
D. S. McDONALD
Keyword(s):  
Organic Matter ◽  
Humic Acid ◽  
Organic Carbon ◽  
Spectral Properties ◽  
High Sodium ◽  
Standard Soil ◽  
Humic Materials ◽  
High Level ◽  
Humus Fractionation

The pedogenetic origin of dark subsurface horizons of a Dark Brown Solod and Solod-like soil from the prairie region of Saskatchewan was studied. The soils had thick, strongly acidic A horizons, dark-colored B horizons and saline C horizons. Standard soil analyses, humus fractionation and measurement of the plant opal phytolith content of the 20–50 μm fraction were done. The dark B horizons contained 1.5 to 2.0 times more organic carbon than the adjacent horizons. The phytolith content decreased regularly with depth, indicating that the dark horizons were not buried surfaces. Consistent with generally accepted theories, they appeared to have formed by the translocation of humic materials in a high sodium environment. The illuvial humus of the B horizon was predominantly humic acid with a high level of aromaticity. Leachates of sodium-saturated A horizon soil contained organic matter with a ratio of humic:fulvic acids and spectral properties similar to the organic matter of the illuvial B horizons.

scholarly journals Haplic chernozems humus condition of Western Bug and Styr terraced landscapes

2016 ◽  
pp. 296-308
Author(s):  
Pavlo Papish ◽  
Halyna Ivanyuk ◽  
Ihor Papish
Keyword(s):  
Organic Matter ◽  
Clay Minerals ◽  
Optical Density ◽  
Humic Acids ◽  
Fulvic Acids ◽  
Soil Thickness ◽  
Humus Profile ◽  
Haplic Chernozems ◽  
High Degree ◽  
Very High

Volyn Upland Haplic Chernozems are distributed mainly on the terrace landscapes of the Western Bug and the Styr and their tributaries (Chornohuzka, Luha, Lypa). Most of these soils are old ploughlands that have experienced various types of degradation. Haplic Chernozems are low-humus soils and they have low storages of humus substance in the 20 cm arable layer and middle storages of humus in 100 cm soil thickness. There is correlation of C humic acids to C fulvic acids within 1.2–3.3 in the humus profile. Among the various fractions of humic substances the 2nd fraction associated to Calcium dominates. A content of “free” humic acids (1rst fraction) is very low and the amount of humin is low. The optical density of humic acids ( 0,001% НА Е1 cm, 465 nm ) are high and very high. The organic matter of Volyn Upland Haplic Chernozems has some regional peculiarities. First, it caused by topographical conditions of its formation and evolution in the Holocene. Chernozems of the 1st terrace of the River Western Bug are extremely deep. They have progressive-accumulative type of humus distribution in profile, humate type of humus in upper 100 cm layer, a very high degree of organic matter humification and the same content of humic fraction associated to Calcium and lowmiddle content of 3rd fraction associated to clay minerals. The molecules of humic acids in the humus horizon of Chernozems of the 1rst terrace are better structured that indicates the older age of humus in these soils. Chernozems of the 2nd terrace above the floodplain of the River Styr are middle-deep soils. They are characterised by the regressive-accumulative type of humus distribution in profile, humate-fulvate type of humus and very high degree of organic matter humification only in 25–50 cm layer. The content of fractions associated to Calcium and clay minerals is predominantly high. Key words: Haplic Chernozems, humus, humic acids, fulvic acids, optical density, humus condition.

Capillary electrophoresis characterisation of humic acids: application to diverse forest soil samples

2011 ◽  
Vol 8 (6) ◽  
pp. 589 ◽  
Author(s):  
Michael Tatzber ◽  
Franz Mutsch ◽  
Axel Mentler ◽  
Ernst Leitgeb ◽  
Michael Englisch ◽  
...  
Keyword(s):  
Organic Matter ◽  
Capillary Electrophoresis ◽  
Soil Organic Matter ◽  
Organic Carbon ◽  
Humic Acids ◽  
Soil Characteristics ◽  
Soil Samples ◽  
The Other ◽  
Total Carbon ◽  
Soil Layers

Environmental contextAnalysis of soil organic matter is important for understanding turnover and stabilisation processes of organic carbon in soils. Capillary electrophoresis is used here to investigate humic acids from soils of diverse forest sites, and show that the patterns of signals are indicative of soil characteristics. The method provides useful information of soil types and complements the existing set of methods for humic acid characterisation. AbstractAnalyses of humic substances provide very useful information about turnover characteristics and stabilisation processes of soil organic matter in environmental soil samples. The present study investigates 113 samples of forest soils from three different layers (undecomposed litter (L), if present, mixed samples of F (intermediate decomposed) and H (highly decomposed) organic matter (FH) and upper mineral soil layers (Ah horizon) from 0 to 5 cm) by extracting humic acids (HAs) and recording electropherograms. Five signals of these electropherograms were evaluated and correlated with basic parameters from soil (organic carbon, Corg, and total nitrogen, Nt, and extraction yields of HAs) and HAs (total carbon, Ct, and Nt), and with signals from photometry, mid-infrared and fluorescence spectroscopy. The developed method was able to separate HAs from different soil layers by calculating a discriminant function based on the five evaluated electrophoretic signals. The dataset of this work opened the opportunity to correlate the observed electrophoretic signals with the other determined soil parameters and spectroscopic signals. This can be seen as a very important step in the direction to assignments of the obtained electrophoretic signals. Soil characteristics were reflected quite well by this method and, combined with the other approaches, it is suitable for applications in further studies.

scholarly journals Combined organic amendment effects on eggplant yield, soil fertility characteristics and humic acid quality

1969 ◽  
Vol 100 (2) ◽  
pp. 101-122
Author(s):  
Ian C. Pagán-Roig ◽  
Joaquín A. Chong ◽  
José A. Dumas ◽  
Consuelo Estévez de Jensen
Keyword(s):  
Organic Matter ◽  
Humic Acid ◽  
Soil Fertility ◽  
Humic Acids ◽  
Organic Amendments ◽  
Chemical Properties ◽  
Soil Chemical Properties ◽  
Agricultural System ◽  
Vegetable Production ◽  
Amended Soils

Soil fertility and organic matter have been hindered due to unsustainable agricultural practices. There is a need to develop and better understand the effect of combined organic amendments that have the potential to increase soil fertility and agricultural system sustainability. Compost incorporations, the use of coordinated fallows and other biological amendments are alternatives to better the soil and increase crop yield. Information is scarce about the effect of combined organic amendments over soil chemical properties and their impact on vegetable production. The objective of the present study was to assess the effect of a combination of organic amendments we termed soil treatment management cycles (STMC) on soil chemical properties and eggplant yield in a San Antón soil. The STMC amendments consisted of incorporating organic matter from coffee pulp compost, planting and incorporation of a mixture of four green manure species, adding a mycorrhizae culture to the soil as well as compost tea. The different STMC were: control, no STMC (CL0); one STMC (CL1); two consecutive STMC (CL2); and three consecutive STMC (CL3). Results showed that CL1 was enough to significantly increase organic matter, P, K and S content in the soil compared with the non-amended soil. The concentration of Ca was significantly increased by three (CL3), and that of Mg by three (CL3) and two (CL2) STMC, compared to the other treatments. All treatments significantly changed soil pH, buffering it toward neutrality with increasing cycles when compared with pH 7.9 of no STMC control soils. Treatments CL1, CL2 and CL3 increased humic acid content 2.8, 3.8 and 5.9 times, respectively, when compared with CL0. Humic acids, extracted from unamended soils exhibited more condensation and more aromaticity when compared with those of amended soils. Nevertheless, the humic acids of amended soils showed high levels of polymerization. The enhancement in soil properties promoted by STMC resulted in an increase in eggplant fruit yield and biomass production.

scholarly journals Assessments of Organic Carbon Stabilization Using the Spectroscopic Characteristics of Humic Acids Separated from Soils of the Lena River Delta

Separations ◽  
2021 ◽  
Vol 8 (6) ◽  
pp. 87
Author(s):  
Vyacheslav Polyakov ◽  
Evgeny Abakumov
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Organic Carbon ◽  
Humic Acids ◽  
Terrestrial Ecosystems ◽  
River Delta ◽  
The Arctic ◽  
Lena River ◽  
Organic Matter Stabilization ◽  
Lena River Delta

In the Arctic zone, where up to 1024 × 1013 kg of organic matter is stored in permafrost-affected soils, soil organic matter consists of about 50% humic substances. Based on the analysis of the molecular composition of humic acids, we assessed the processes of accumulation of the key structural fragments, their transformations and the stabilization rates of carbon pools in soils in general. The landscape of the Lena River delta is the largest storage of stabilized organic matter in the Arctic. There is active accumulation and deposition of a significant amount of soil organic carbon from terrestrial ecosystems in a permafrost state. Under ongoing climate change, carbon emission fluxes into the atmosphere are estimated to be higher than the sequestration and storing of carbon compounds. Thus, investigation of soil organic matter stabilization mechanisms and rates is quite an urgent topic regarding polar soils. For study of molecular elemental composition, humic acids were separated from the soils of the Lena River delta. Key structural fragments of humic matter were identified and quantified by CP/MAS 13C NMR spectroscopy: carboxyl (–COOR); carbonyl (–C=O); CH3–; CH2–; CH-aliphatic; –C-OR alcohols, esters and carbohydrates; and the phenolic (Ar-OH), quinone (Ar = O) and aromatic (Ar–) groups as benchmark Cryosols of the Lena delta river terrestrial ecosystem. Under the conditions of thermodynamic evolutionary selection, during the change between the dry and wet seasons, up to 41% of aromatic and carboxyl fragments accumulated in humic acids. Data obtained showed that three main groups of carbon played the most important role in soil organic matter stabilization, namely C, H-alkyls ((CH2)n/CH/C and CH3), aromatic compounds (C-C/C-H, C-O) and an OCH group (OCH/OCq). The variations of these carbon species’ content in separated humics, with special reference to soil–permafrost organic profiles’ recalcitrance in the current environment, is discussed.

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