scholarly journals A rainfall simulation study of erosion of some calcareous soils

2013 ◽  
Vol 3 (3) ◽  
pp. 179-183 ◽  
Keyword(s):  
Calcium Carbonate ◽  
Cation Exchange Capacity ◽  
Soil Loss ◽  
Clay Fraction ◽  
Calcareous Soils ◽  
Exchange Capacity ◽  
Rainfall Simulation ◽  
Runoff And Soil Loss ◽  
Raindrop Impact ◽  
Rain Simulator

In order to study the erodibility characteristics of some calcareous soils from Central Greece, the instability of aggregates of 2.0-4.7 mm in water was studied. Soil loss experiments were also conducted in the laboratory using a rain simulator where soil loss was measured and the soils’ attitude was studied under the conditions of simulated rainfall. It was found that the instability of aggregates is negatively correlated with cation exchange capacity and the total specific surface of soils. Also the calcium carbonate content affects positively the aggregates instability. The process which seems to control dominantly the time that runoff occurs and the runoff and soil loss quantity, is the creation of surface seals with raindrop impact due to large calcium carbonate quantities that are met in the clay fraction.

Cation exchange capacity of loess and overlying soil in the non-carbonate loess sections, North-Western Croatia

2013 ◽  
Vol 5 (4) ◽  
Author(s):  
Nenad Tomašić ◽  
Štefica Kampić ◽  
Iva Cindrić ◽  
Kristina Pikelj ◽  
Mavro Lučić ◽  
...  
Keyword(s):  
Organic Matter ◽  
Cation Exchange ◽  
Transition Zone ◽  
Cation Exchange Capacity ◽  
Clay Fraction ◽  
Sample Pretreatment ◽  
Loess Soil ◽  
Exchange Capacity ◽  
Oxalate Extraction ◽  
North Western

AbstractThe adsorption properties in terms of cation exchange capacity and their relation to the soil and sediment constituents (clay minerals, Fe-, Mn-, and Al-oxyhydroxides, organic matter) were investigated in loess, soil-loess transition zone, and soil at four loess-soil sections in North-Western Croatia. Cation exchange capacity of the bulk samples, the samples after oxalate extraction of Fe, Mn and Al, and after removal of organic matter, as well as of the separated clay fraction, was determined using copper ethylenediamine. Cation exchange capacity (pH∼7) of the bulk samples ranges from 5 to 12 cmolc/kg in soil, from 7 to 15 cmolc/kg in the soil-loess transition zone, and from 12 to 20 cmolc/kg in loess. Generally, CEC values increase with depth. Oxalate extraction of Fe, Mn, and Al, and removal of organic matter cause a CEC decrease of 3–38% and 8–55%, respectively, proving a considerable influence of these constituents to the bulk CEC values. In the separated clay fraction (<2 μm) CEC values are up to several times higher relative to those in the bulk samples. The measured CEC values of the bulk samples generally correspond to the clay mineral content identified. Also, a slight increase in muscovite/illite content with depth and the vermiculite occurrence in the loess horizon are concomitant with the CEC increase in deeper horizons, irrespective of the sample pretreatment.

scholarly journals Mineralogical and physico-chemical characterizations of clay from Keur Saër (Senegal)

Clay Minerals ◽  
2012 ◽  
Vol 47 (4) ◽  
pp. 499-511 ◽  
Author(s):  
A. Mbaye ◽  
C. A. K. Diop ◽  
B. Rhouta ◽  
J. M. Brendle ◽  
F. Senocq ◽  
...  
Keyword(s):  
Cation Exchange ◽  
Cation Exchange Capacity ◽  
Clay Fraction ◽  
Exchange Capacity ◽  
Raw Material ◽  
Basic Knowledge ◽  
Mineral Mixture ◽  
Fine Clay ◽  
Main Component ◽  
Adsorption Desorption

AbstractThere is interest in exploiting and developing natural resources, particularly deposits of natural clays. Senegal has several clay mineral deposits for which chemical and mineralogical compositions have been little studied. Some of these natural materials are nowadays used in pottery and ceramics. To extend applications, a better basic knowledge is required and, for this objective, the raw clay and separated <2 μm clay fraction from Keur Saër (Senegal) were subjected to chemical and mineralogical studies. Several techniques including X-ray diffraction (XRD), thermal analysis (TG-DTA), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), N2 adsorption-desorption isotherms, cation exchange capacity (CEC) measurements and solid state nuclear magnetic resonance (NMR) have been used to characterize the material. It was found that the raw clay and the separated clay fraction consist of a mineral mixture in which kaolinite is the main component. 29Si and 27Al MAS-NMR spectra show the presence of silicon atoms linked to three other silicon atoms via an oxygen atom and six coordinated Al atoms. Significant increases in the specific surface area and cation exchange capacity were observed on purification, reaching a maximum of about 73.2 m2g–1 and 9.5 meq/100 g for the separated fine clay fraction while the values for the raw material were around 28.9 m2g–1 and 7.3 meq/100 g.

Chemical fertility of krasnozems - a review

Soil Research ◽  
1994 ◽  
Vol 32 (5) ◽  
pp. 1015
Author(s):  
PW Moody
Keyword(s):  
Organic Matter ◽  
Cation Exchange ◽  
Anion Exchange ◽  
Cation Exchange Capacity ◽  
Clay Fraction ◽  
Exchange Capacity ◽  
Published Data ◽  
Total N ◽  
Eastern Australia ◽  
Ph Buffer

Krasnozems (Ferrosols) characteristically have high contents of citrate-dithionite extractable Fe and moderate to high contents of clay throughout the profile. They typically have low cation exchange capacity (2-20 cmolc kg-1), high P sorbing ability, and a significant anion exchange capacity at depth. The chemistry of krasnozems is dominated by the variable charge characteristics of the organic matter and the oxy-hydroxides of Fe and Al which occur in the predominantly kaolinitic clay fraction. The effects of surface charge characteristics, organic matter, and extractable iron and aluminium on the cation and anion exchange capacities, P sorbing abilities and pH buffer capacities of Australian krasnozems are reviewed. A selection of reports of nutrient deficiencies and toxicities in these soils is presented and briefly discussed. Published data on the chemical composition of the soil solutions of krasnozems are reviewed. Data from a suite of paired (undeveloped and developed) krasnozem profiles from eastern Australia indicate that exchangeable Ca and Mg, effective cation exchange capacity (ECEC), pH buffer capacity (pHBC) and total N decrease significantly (P < 0.05) in the A horizon following development, while exchangeable K, ECEC and pHBC decrease (P < 0-05) in the B horizon. The decreases in the A horizon are shown to be a direct consequence of the decline in organic matter which occurs following development. Because of the crucial role that organic matter plays in the chemical fertility of krasnozems, they are less likely to maintain their fertility under exploitative conditions than other productive clay soils such as Vertosols. It is concluded that the sustainable use of krasnozems will depend on maintenance or enhancement of organic matter levels, maintenance of surface and subsoil pH by regular application of amendments, minimization of erosion, and replacement of nutrients removed in harvested products.

scholarly journals The effects of Rubus hyrcanus L. and Philonotis marchica (Hedw.) Brid. on soil loss prevention from cutslopes of a forest road

2012 ◽  
Vol 58 (No. 8) ◽  
pp. 337-344 ◽  
Author(s):  
A. Parsakhoo ◽  
M. Lotfalian ◽  
A. Kavian ◽  
S.A. Hosseini ◽  
M. Demir
Keyword(s):  
Soil Loss ◽  
Sediment Concentration ◽  
Rainfall Simulation ◽  
Runoff Generation ◽  
Forest Roads ◽  
Northern Forest ◽  
Forest Road ◽  
Runoff And Soil Loss ◽  
The City ◽  
Runoff And Sedimentation

The effects of Rubus hyrcanus L. and Philonotis marchica (Hedw.) Bridon on runoff generation and soil loss from cutslopes of forest roads were investigated. The study was conducted at the northern forest of Iran, about 30 km south of the city of Sari. Runoff and sedimentation after each rainfall simulation and chemical and physical soil properties were measured in 14 plots with an area of 0.48 m<sup>2</sup>. The obtained results indicate that the vegetation dominated by Philonotis marchica exhibited the higher runoff coefficient and soil loss, with averages of 27.25% and 92.40&nbsp;g&middot;m<sup>&ndash;2</sup>&middot;h<sup>&ndash;1</sup>(gram per square meter per hour), respectively, in comparison to Rubus hyrcanus. For Philonotis marchica (Hedw.) Brid. the sediment concentration increased quickly at the beginning of rainfall simulations and after 10&ndash;12 min there was a fast decrease in sediment concentration. The peak of sediment concentration was for the Rubus hyrcanus L. in the 13<sup>th</sup>&ndash;15<sup>th</sup> min In conclusion, Rubus hyrcanus L. prevented or decreased the risk of runoff and soil loss from cutslopes of forest roads in our study area. &nbsp;

Comparative Study of Organoclays with Ionic Surfactant

2014 ◽  
Vol 798-799 ◽  
pp. 9-14 ◽  
Author(s):  
B.M.A. de Brito ◽  
Juliana Melo Cartaxo ◽  
Julliana Marques Rocha Costa ◽  
Heber Carlos Ferreira ◽  
Gelmires Araújo Neves
Keyword(s):  
Comparative Study ◽  
Organic Compounds ◽  
Cation Exchange Capacity ◽  
Clay Fraction ◽  
Exchange Capacity ◽  
Ionic Surfactants ◽  
Ionic Surfactant ◽  
Organophilic Clays ◽  
Swelling Capacity ◽  
High Cation Exchange Capacity

The clays of the smectite group, mainly montmorillonite, are widely used in the production of organoclays due to the small dimensions of the crystals, high cation exchange capacity (CEC), and swelling capacity in water, which lead to a rapid and efficient intercalation of organic compounds used in the synthesis. In this context, this research was intended to make a comparative study of clays organofilized with ionic surfactants through their respective CEC. We selected four samples of bentonites, namely Chocolate (Boa Vista, PB), Brasgel (industrial), Dark Bentonite (Pedra Lavrada, PB) and M400 Bentonite (industrial). The natural samples were characterized through XRD, EDX, TA and GA, and the organofilized ones through XRD. The characterization tests showed that the samples are composed of clay minerals of the smectite group, the CEC values ​​were insignificant changes when comparing the values ​​of natural and activated clays with sodium carbonate. And the levels indicated by the CEC for the ionic surfactant Praepagem HY proved insufficient to transform the organophilic clays, as the nominees for the ionic surfactant Praepagem WB led to adequate results regarding the incorporation of the surfactant in the clay fraction of the studied samples.

scholarly journals A Comparison of Methods for the Determination of Cation Exchange Capacity of Soils/Porównanie Metod Oznaczania Pojemności Wymiany Kationów I Sumy Kationów Wymiennych W Glebach

2014 ◽  
Vol 21 (3) ◽  
pp. 487-498 ◽  
Author(s):  
Dawid Jaremko ◽  
Dorota Kalembasa
Keyword(s):  
Organic Matter ◽  
Cation Exchange ◽  
Cation Exchange Capacity ◽  
Sodium Acetate ◽  
Calcareous Soils ◽  
Acid Soils ◽  
Barium Chloride ◽  
Exchange Capacity ◽  
Organic Carbon Content

Abstract The object of this study was to compare the results obtained with four methods of determination of cation exchange capacity (CEC) and sum of exchangeable cations (Ca, Mg, K) in soils. One of these methods is Kappen’s method and the others methods are based on different extracting reagents: sodium acetate (pH = 8.2), barium chloride and hexaamminecobalt(III) chloride. Values measured with barium ions and hexaamminecobalt(III) ions as index cations are very comparable and these two methods can be considered as equivalent. Kappen’s method gives overestimated results, especially for acid soils reach in organic matter and very calcareous soils. Sodium acetate, buffering the pH of the extracting solution, causes increase of numbers of negatively charged sites and particularly those bonded to organic matter and for this reason values obtained with this method are overestimated. Nevertheless, it is possible to correct this error for a given soil sample by regression equation considering pH of soil, clay and organic carbon content.

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