Carbonate and organic carbon content in the recent sediments of Elefsis bay as indicators for the paleoenviromental evolution of the system.

During the Holocene period Elefsis bay acted as a semi-enclosed system obstructing water circulation. In some areas, sampling has revealed the problems of anoxia that prevails in the bay, which has been worse during the summer months. Analyses undertaken in a core from the bay of Elefsis showed notable changes in carbonate and organic material, which prove the paleo-environmental evolution of the bay. Such changes of carbonate are due to the different deposition of calcium carbonate from biogenic source (probably and from inorganic source). The variation of organic carbon is still a factor of limited water circulation in the bay.

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Physical and chemical protection of soil organic carbon in three agricultural soils with different contents of calcium carbonate

Soil Research ◽

10.1071/sr99102 ◽

2000 ◽

Vol 38 (5) ◽

pp. 1005 ◽

Cited By ~ 96

Author(s):

A. Clough ◽

J. O. Skjemstad

Keyword(s):

Organic Carbon ◽

Carbon Content ◽

Organic Material ◽

Agricultural Soils ◽

Calcareous Soils ◽

High Energy ◽

Organic Carbon Content ◽

Photo Oxidation ◽

Active Organic Carbon ◽

Physical And Chemical

The amount of organic carbon physically protected by entrapment within aggregates and through polyvalent cation–organic matter bridging was determined on non-calcareous and calcareous soils. The composition of organic carbon in whole soils and <53 m soil fractions was determined by 13C NMR analysis. High energy photo-oxidation was carried out on <53 m fractions and results from the NMR spectra showed 17–40% of organic carbon was in a condensed aromatic form, most likely charcoal (char). The concept that organic material remaining after photo-oxidation may be physically protected within aggregates was investigated by treating soils with a mild acid prior to photo-oxidation. More organic material was protected in the calcareous than the non-calcareous soils, regardless of whether the calcium occurred naturally or was an amendment. Acid treatment indicated that the presence of exchangeable calcium reduced losses of organic material upon photo-oxidation by about 7% due to calcium bridging. These results have implications for N fertiliser recommendations based upon organic carbon content. Firstly, calcium does not impact upon degradability of organic material to an extent likely to affect N fertiliser recommendations. Secondly, standard assessment techniques overestimate active organic carbon content in soils with high char content.

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Dynamics of selected chemical and microbiological properties changes in soils after application of ultra-fine powdered calcium carbonate – incubation studies

10.5194/egusphere-egu2020-7128 ◽

2020 ◽

Author(s):

Karolina Woźnica ◽

Michał Gąsiorek ◽

Justyna Sokołowska ◽

Agnieszka Józefowska ◽

Tomasz Zaleski

Keyword(s):

Calcium Carbonate ◽

Organic Carbon ◽

Dissolved Organic Carbon ◽

Soil Properties ◽

Carbon Content ◽

Buffer Capacity ◽

Microbial Biomass Carbon ◽

Soil Samples ◽

Organic Carbon Content ◽

Biomass Carbon

Soil acidification is a serious problem on a global scale, about 30% of land surface is occupied by acidic soils (pH&#8804; 5.5). Recent research indicates, that more than 50% of arable soils in Poland have too low pH. Acid soils are characterised the ability to mobilize toxic metals and increased plant uptake as well as decreased microbial activity in the soil. Progressive acidification leads to degradation of soils and caused that they are marginal for agricultural production. Soil acidification is a naturally occurring process, but only when natural factors are supported by intensive human activity, especially by nitrogen fertilisers application, intensive degradation is observed. Traditionally method to increase soil pH is the application of lime materials e.g. calcite, burnt lime or dolomite. The liming efficiency depends on lime material type (primarily chemical form of calcium compounds), the neutralising value, lime application method, soil properties and the particle size distribution of lime. The aim of this research was to determine the rate of action and influence of ultra-fine powdered calcium carbonate on selected chemical and microbiological soil properties.The incubation studies were conducted on the three soils (G1, G2 &#8211; silt loam and G3 &#8211; sandy loam). Soil samples were taken from the 0-20 cm layer. Soil properties were measured after 7, 14, 30, 60 and 120 days of incubation. The liming factor was ultra-fine powdered calcium carbonate with particle size distribution < 0.08 mm. The application dose was calculated for 0.5 soil hydrolytic acidity. In the soil samples pHKCl, buffer capacity, microbial biomass carbon and dissolved organic carbon content were measured.Application of lime caused an increase of pH value in all studied soils. The highest increase of the pHKCl was noted between 0 to 7th day of incubation. Afterward, the pHKCl decreased slowly for the soil G1 and G2. However, in the soil G3 significantly decreased just after 7th to 14th day, and afterward, the pHKCl decreased slowly to the end of the incubation period. As a result of liming long-term changes in soil buffer capacity were not noted. The studied soils were characterised by the higher buffer capacity in alkaline than in acidic range. The microbial biomass carbon content was varied during the incubation in all studied soils. The dissolved organic carbon content increased during the incubation, starting from the 7th to the 120th day of incubation for G2 and G3 soils and from 14th to last day of incubation for G1 soil. Application of lime caused an increase of the dissolved organic carbon content in all studied soils. These studies show that application of ultra-fine powdered calcium carbonate is an effective and fast way to improve soil properties.

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Investigation of Organic Matter Content of Hungarian Oil Shale and Its Influence on Sorption of 2,4-Dichlorophenol

Periodica Polytechnica Chemical Engineering ◽

10.3311/ppch.15002 ◽

2019 ◽

Vol 64 (2) ◽

pp. 230-237

Author(s):

Renata Rauch ◽

Rita Foldenyi

Keyword(s):

Organic Matter ◽

Organic Carbon ◽

Total Organic Carbon ◽

Carbon Content ◽

Organic Material ◽

Oil Shale ◽

Total Organic Carbon Content ◽

Aliphatic Chain ◽

Organic Carbon Content

It is not only Total Organic Carbon content (TOC) but also the type of Organic Matter (OM) that the sorption of organic pollutants by soils or other natural absorbents is correlated with. Therefore, the characterization of organic components in the adsorbents is very important to elucidate sorption mechanisms.Oil shale samples were collected in Pula, Hungary. The TOC content of the investigated samples was approximately 6.8-40.1 m/m %. The characterization of the organic matter in samples was carried out by using Scanning Electron Microscopy (SEM), elemental analysis, thermal analysis, and GC-MS technics. The results predominantly indicated the presence of a low degree of the branching of aliphatic chain components in the samples. The Humic Substances (HS) content of the samples was only 1-6 m/m %, which could be determined after the treatment of oil shale with hydrogen peroxide.The influence of the amount and type of organic material in oil shale samples was studied on the adsorption of 2,4-dichlorophenol (2,4-DCP) as a model contaminant. For this aim a series of batch equilibration experiments was carried out. The results show that the total organic carbon content of samples is a strong indicator of 2,4-DCP adsorption, while the HS content is an important feature controlling sorption capacity. The study suggests that the special organic matter (kerogen) content of the oil shale plays a major role in its high adsorption capacity and in the nonlinearity of the isotherms. The HS covering the surface could decrease the sorption capacities despite the fact that though the amount of this organic material is quite low.

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Palaeoproductivity in the Ross Sea, Antarctica, during the last 15 kyr BP and its link with ice-core temperature proxies

Annals of Glaciology ◽

10.3189/172756404781814582 ◽

2004 ◽

Vol 39 ◽

pp. 445-451 ◽

Cited By ~ 6

Author(s):

Cristinamaria Salvi ◽

Gianguido Salvi ◽

Barbara Stenni ◽

Antonio Brambati

Keyword(s):

Organic Carbon ◽

Carbon Content ◽

Ross Sea ◽

Ice Core ◽

Sediment Cores ◽

Organic Carbon Content ◽

Last Deglaciation ◽

The Holocene ◽

The Last Deglaciation ◽

The Antarctic

AbstractA detailed study of organic carbon content obtained from two sediment cores collected in the Joides basin, western Ross Sea, Antarctica, was carried out. The variations observed during the last deglaciation and the Holocene were compared to the high-resolution climatic records (EPICA DC and Taylor Dome) preserved in the ice. The importance of the carbon content as a proxy for palaeoclimatic and palaeoenvironmental changes was investigated. A dramatic decrease in the Ross Sea palaeoproductivity was observed during the Antarctic Cold Reversal (12.5–14 kyr BP). Another decrease in total organic carbon in the second half of the Holocene (after 5–6 kyr BP) confirms the climate worsening observed in previous studies.

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Characterization and Classification of Soils of Bharuch Taluka in Bharuch District of Gujarat

Agropedology ◽

10.47114/j.agroped.2018.dec2 ◽

2019 ◽

Vol 28 (2) ◽

Author(s):

Abhishek Jangir ◽

◽

R. P. Sharma ◽

G. Tiwari ◽

B. Dash ◽

...

Keyword(s):

Calcium Carbonate ◽

Organic Carbon ◽

Carbon Content ◽

Soil Survey ◽

Base Saturation ◽

Organic Carbon Content ◽

Alkaline Ph ◽

Soil Series ◽

High Base

A detailed soil survey was undertaken at 1:10000 scale to describe, characterize, classify and evaluate the soils of Bharuch taluka, Bharuch district, Gujarat. Old and recent basaltic alluvial plains are the major landforms of the area. A total of 74 pedons, representing old (41 pedons) and recent (33 pedons) alluvial plains were studied. The soils were correlated and three soil series viz. Umraj, Derol and Singdot were identified. The Umraj belong to a very fine, smectitic Typic Haplusterts covers 30,839 ha (48.5 %) area, whereas Derol and Singdot a fine, smectitic Vertic Haplustepts and fine, mixed, Typic Haplustepts covers 20,604 ha (32.5 %) and 4,164 ha (6.6 %) area, respectively. The sand, silt and clay in the soils varied from 8 to 31, 24 to 49 and 23 to 67 per cent, respectively. The soils were very deep, neutral to slightly alkaline (pH 7.3 to 8.4) with low to medium in organic carbon content (0.14 to 0.58 %), low to high in calcium carbonate (1.9 to 16.5 %) with medium to high CEC [39.4 to 62.0 cmol (p+) kg-1] and high base saturation (67.4 to 92.0 %). Soils were assessed as highly to moderately suitable for major crops (cotton, pigeonpea, maize, sugarcane, wheat and chickpea).

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Chemical properties of salt-affected soils in north Kent and their relationship to soil instability

The Journal of Agricultural Science ◽

10.1017/s0021859600080904 ◽

1987 ◽

Vol 109 (1) ◽

pp. 1-6 ◽

Cited By ~ 4

Author(s):

P. J. Loveland ◽

J. Hazelden ◽

R. G. Sturdy

Keyword(s):

Electrical Conductivity ◽

Calcium Carbonate ◽

Organic Carbon ◽

Carbon Content ◽

Carbonate Content ◽

Organic Carbon Content ◽

Exchangeable Sodium ◽

Calcium Carbonate Content ◽

Soil Instability ◽

Dispersion Ratio

SummarySoil instability, as measured by the dispersion ratios of the reclaimed salt-marsh soils of ca. 70 km2 of north Kent, was assessed on samples taken from 0–15, 35–50 and 70–85 cm depths from sites at the intersects of a 250 m square grid or along transects. The dispersion ratios were related to other soil properties including exchangeable sodium, potassium and magnesium percentages, organic carbon content, calcium carbonate content and electrical conductivity. The dispersion ratio correlates most closely with exchangeable sodium percentage and organic carbon content; weaker correlations exist with exchangeable potassium and calcium carbonate contents. Dispersion ratios rise sharply, i.e. reflect a marked increase in soil instability, when organic carbon content is less than 2·5% and calcium carbonate content is less than 2%. Magnesium has little effect on the dispersion ratio. The soil solution salt concentration (as expressed by electrical conductivity) is too low over much of the area to promote flocculation, and hence stability, of the soil clays.

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