scholarly journals Determination of soil specific surface area by water vapor adsorption: I Drying of soil samples

1987 ◽  
Vol 59 (2) ◽  
pp. 63-65
Author(s):  
Raina Niskanen ◽  
Väinö Mäntylahti
Keyword(s):  
Organic Carbon ◽  
Carbon Content ◽  
Mineral Soil ◽  
Clay Content ◽  
Fine Sand ◽  
Water Vapor Adsorption ◽  
Soil Samples ◽  
Organic Carbon Content ◽  
Clay Sample

Drying of three mineral soil samples (clay content 4—58 %, organic carbon content 1—5 %) equilibrated at 75.5 % relative humidity was studied. The soils were dried in an oven at +50°C, +70°C and + 105°C for 4 and 8 hours and in a desiccator over pure concentrated H2SO4 and P2O5. Drying over desiccants for 8 hours removed less water than drying at + 50°C. Drying over desiccants for 3—7 days was as efficient as drying at +70°C, for 14—24 days as efficient as 4 hours of drying at + 105°C. Eight hours of drying at + 105°C seemed to be too drastic, because it caused a greater weight loss in the clay sample of 5 % organic carbon content than did prolonged desiccant-drying. Drying at + 70°Cremoved as much water from fine sand which contained 4 % clay as prolonged desiccant-drying.

scholarly journals Determination of soil specific surface area by water vapor adsorption: II Dependence of soil specific surface area on clay and organic carbon content

1987 ◽  
Vol 59 (2) ◽  
pp. 67-72
Author(s):  
Raina Niskanen ◽  
Väinö Mäntylahti
Keyword(s):  
Water Vapor ◽  
Organic Carbon ◽  
Specific Surface ◽  
Carbon Content ◽  
Surface Area ◽  
Specific Surface Area ◽  
Mineral Soil ◽  
Water Vapor Adsorption ◽  
Organic Carbon Content ◽  
Vapor Adsorption

The specific surface area of 60 mineral soil samples estimated by water vapor adsorption at 20 % relative humidity ranged from 12.1 ± 3.6 to 225.1 ±18.4 m2/g. Clay (range 1—72 %) and organic carbon content (0.7—14.6 %) together explained 84 % of the variation in the surface area. The regression equation predicting the specific surface area of soil was surface area (m2/g) =2.69+ 1.23clay-% +8.69org.C-%.

scholarly journals CHARACTERISTICS OF RICE SOILS FROM THE TIDAL FLAT AREAS OF MUSI BANYUASIN, SOUTH SUMATRA

2016 ◽  
Vol 2 (1) ◽  
pp. 10 ◽  
Author(s):  
B.H. Prasetyo ◽  
S. Suping ◽  
Subagyo H. ◽  
Mujiono Mujiono ◽  
H. Suhardjo
Keyword(s):  
Organic Carbon ◽  
Tidal Flat ◽  
Amorphous Materials ◽  
Mineral Soil ◽  
Soil Samples ◽  
Moisture Regime ◽  
Organic Carbon Content ◽  
Rice Soils ◽  
Specific Chemical ◽  
Very High

Tidal flats in the Musi Banyuasin region that cover more than 200,000 ha are the largest area for agricultural development in South Sumatra Province. Only about a half of this has been used for tidal swamp rice fields, therefore, the other half needs to be developed. To obtain a better understanding of their properties for appropriate soil management, soil characteristics of the area need to be studied. To characterize the soil, thirty-four soil samples from seven soil profiles were analyzed for their chemical and mineralogical composition at the laboratories of the Center for Soil and Agroclimate Research and Development. The results indicate that soils from the tidal flat areas have an aquic soil moisture regime, the upper parts of the soils are mostly ripe, and most of the pedons show the presence of sulfidic materials below 65 cm of the mineral soil surface. The soils are classified as Sulfic Endoaquept (P1, P2), Histic Sulfaquent (P3), Typic Sulfaquept (P4), Fluvaquentic Endoaquept (P5), and Sulfic Hydraquent (P6, P7). Mineral composition of the sand fraction is dominated by quartz, while the clay minerals consist of predominantly kaolinite, mixed with small amount of smectite, illite, quartz, and crystoballite. Organic carbon content is high to very high, potential phosphate content of most pedons ranges from very low to medium, while potential potassium content varies from very low to medium in the upper layers and medium to very high in the bottom layers. Phosphate retention of topsoil sample varies from 56 to 97%, and is positively correlated (r2 = 0.73) with aluminum from amorphous materials. Exchangeable cations are dominated by Mg cation, and in all pedons cation exchange capacity values are medium to very high, and seem to be influenced by organic carbon. Specific chemical properties, particularly soil pH and content of exchangeable aluminum exhibit a significant change about 1-2 months after soil samples were taken from the field. Theoretically, interaction between good water management and fertilizer application are among the choices of management to make these soils productive.

Changes in dispersible clay content, organic carbon content, and electrolyte composition following incubation of sodic soil

Soil Research ◽  
1998 ◽  
Vol 36 (6) ◽  
pp. 883 ◽  
Author(s):  
P. N. Nelson ◽  
J. A. Baldock ◽  
J. M. Oades
Keyword(s):  
Organic Carbon ◽  
Carbon Content ◽  
Water Content ◽  
Clay Content ◽  
Electrolyte Composition ◽  
Organic Carbon Content ◽  
Sodic Soils ◽  
Sodic Soil ◽  
Clay Dispersion ◽  
Dispersible Clay

Measurement of dispersible clay is important for the diagnosis of structural stability problems in soil. However, clay dispersibility is known to change with water content and time. The purpose of the present study was to determine how incubation of sodic soil under different water content regimes influences clay dispersibility. Two topsoils (depth 0-0·1 m), one sodic [exchangeable sodium percentage (ESP) 9 · 7] and the other non-sodic (ESP 3·8), were collected from an experimental pasture at Kyabram, Victoria, and 2 soils, a sodic topsoil (depth 0-0·1 m, ESP 6·9) and the corresponding subsoil (depth 0·2-0 m, ESP 25·7), were collected from a cropped field at Two Wells, South Australia. The soils were incubated for 264 days in a split-plot design. The main treatments were soil type and incubation water content: continuously air-dry, continuously wet (-50 kPa), or with wet/dry cycles. The subtreatment was water content at analysis: air dry or wet (-50 kPa). Clay dispersion was greater when measured on wet soils than dry soils, irrespective of water contents during the prior incubation. Electrical conductivity increased, and sodium adsorption ratio (SAR), pH, and organic carbon content decreased as a function of the time for which the soils were wet. In the Kyabram soils that were wet when analysed, easily dispersible clay content increased with SAR. Decreases in moderately dispersible clay under the wetting/drying regime were not related to electrolyte composition, and were attributed to particle rearrangement and cementation. The decreases in clay dispersibility with time occurred despite net losses of carbohydrate and aliphatic materials. An implication of the work is that the decomposition of soil organic matter, even in the absence of fresh additions, may reduce clay dispersion in sodic soils by altering electrolyte concentration and composition.

scholarly journals Can mud (silt and clay) concentration be used to predict soil organic carbon content within seagrass ecosystems?

2016 ◽  
Author(s):  
O. Serrano ◽  
P. S. Lavery ◽  
C. M. Duarte ◽  
G. A. Kendrick ◽  
A. Calafat ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Carbon Content ◽  
Clay Content ◽  
Cost Effective ◽  
Blue Carbon ◽  
Organic Carbon Content ◽  
Terrestrial Organic Matter ◽  
Seagrass Meadows ◽  
Clay Concentration ◽  
Seagrass Ecosystems

Abstract. The emerging field of blue carbon science is seeking cost-effective ways to estimate the organic carbon content of soils that are bound by coastal vegetated ecosystems. Organic carbon (Corg) content in terrestrial soils and marine sediments has been correlated with mud content (i.e. silt and clay), however, empirical tests of this theory are lacking for coastal vegetated ecosystems. Here, we compiled data (n = 1345) on the relationship between Corg and mud (i.e. silt and clay, particle sizes <63 μm) contents in seagrass ecosystems (79 cores) and adjacent bare sediments (21 cores) to address whether mud can be used to predict soil Corg content. We also combined these data with the δ13C signatures of the soil Corg to understand the sources of Corg stores. The results showed that mud is positively correlated with soil Corg content only when the contribution of seagrass-derived Corg to the sedimentary Corg pool is relatively low, such as in small and fast growing meadows of the genera Zostera, Halodule and Halophila, and in bare sediments adjacent to seagrass ecosystems. In large and long-living seagrass meadows of the genera Posidonia and Amphibolis there was a lack of, or poor relationship between mud and soil Corg content, related to a higher contribution of seagrass-derived Corg to the sedimentary Corg pool in these meadows. The relative high soil Corg contents with relatively low mud contents (i.e. mud-Corg saturation) together with significant allochthonous inputs of terrestrial organic matter could overall disrupt the correlation expected between soil Corg and mud contents. This study shows that mud (i.e. silt and clay content) is not a universal proxy for blue carbon content in seagrass ecosystems, and therefore should not be applied generally across all seagrass habitats. Mud content can only be used as a proxy to estimate soil Corg content for scaling up purposes when opportunistic and/or low biomass seagrass species (i.e. Zostera, Halodule and Halophila) are present (explaining 34 to 91% of variability), and in bare sediments (explaining 78% of the variability).

STUDIES WITH WASTE SULPHITE LIQUOR: II. WASTE SULPHITE LIQUOR AS A SOIL AGGREGATING AGENT

1959 ◽  
Vol 39 (2) ◽  
pp. 92-97 ◽  
Author(s):  
J. J. Doyle ◽  
A. A. MacLean
Keyword(s):  
Biological Activity ◽  
Organic Carbon ◽  
Carbon Content ◽  
Clay Content ◽  
Organic Carbon Content ◽  
Early Stages

Ammonium-base waste sulphite liquor (solids) (W.S.L.S.) was added to three soils and incubated for 7 weeks. Weekly measurements of organic carbon content and aggregation showed an increase in aggregation to a maximum at 3 weeks, followed by a decline and then by a second increase at 6 weeks. This increase and decline in aggregation paralleled very closely the corresponding biological activity as indicated by loss of organic carbon. Results suggest that decomposition of sugars is responsible for the⁁ development of aggregation in the early stages of incubation and that the ligninsulphonates may have an effect after further incubation.The aggregating effect of W.S.L.S. was compared with that of two synthetic conditioners HPAN and VAMA. The effect of all materials varied considerably with the clay content of the soil. Results indicate that W.S.L.S. is about 1/16 as effective as HPAN and about 1/36 as effective as VAMA.

Determination of Formation Organic Carbon Content Using a New Neutron-Induced Gamma Ray Spectroscopy Service that Directly Measures Carbon

2013 ◽  
Author(s):  
Jorge Gonzalez ◽  
Richard Lewis ◽  
James Hemingway ◽  
Jim Grau ◽  
Erik Rylander ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Carbon Content ◽  
Gamma Ray ◽  
Organic Carbon Content ◽  
Gamma Ray Spectroscopy
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