The Influence of clay content, salinity, stress, and wettability on the dielectric properties of brine‐saturated rocks: 10 Hz to 10 MHz

Geophysics ◽  
1994 ◽  
Vol 59 (6) ◽  
pp. 909-917 ◽  
Author(s):  
Ali A. Garrouch ◽  
Mukul M. Sharma
Keyword(s):  
Dielectric Constant ◽  
Cation Exchange ◽  
Cation Exchange Capacity ◽  
Volume Fraction ◽  
Pore Space ◽  
Ambient Pressure ◽  
Complex Impedance ◽  
Clay Content ◽  
Exchange Capacity ◽  
Constant Frequency

Complex impedance measurements have been performed on 14 shaly sand samples, Berea sandstone, and Ottawa sand‐bentonite packs in a frequency range of 10 Hz to 10 MHz, using both the two‐ and four‐electrode techniques. Measurements have been conducted at an effective radial stress varying from ambient pressure to 4000 psi for brine‐saturated oil‐wet and water‐wet samples. The dielectric permittivity is found to correlate with the clay volume fraction, the cation exchange capacity, and electrochemical potential of the rock samples and to depend strongly on the salinity of the brine used. Stress and wettability are shown to have a small influence on the dielectric constant of fully brine‐saturated rocks. A lower critical frequency is found to characterize the geometry of the pore space. Empirical correlations between the dielectric constant, frequency, permeability, cation exchange capacity, and porosity are presented for the shaly sands used in this study. These correlations provide a means of estimating important petrophysical parameters such as the permeability and the clay content from a nondestructive complex impedance sweep of shaly sands fully saturated with brine.

Ratio of plant to soil concentrations of strontium-85 and its relation to properties of Greek soils

1991 ◽  
Vol 116 (2) ◽  
pp. 275-279 ◽  
Author(s):  
E. P. Papanicolaou ◽  
C. G. Apostolakis ◽  
V. Skarlou ◽  
C. Nobeli ◽  
P. Kritidis
Keyword(s):  
Cation Exchange ◽  
Cation Exchange Capacity ◽  
Plant Material ◽  
Clay Content ◽  
Exchange Capacity ◽  
Absolute Value ◽  
Plant Parts ◽  
Stems And Leaves ◽  
Lower Variability ◽  
Edible Parts

SUMMARYPlant:soil ratios (CRs) of 85Sr concentration were studied in wheat, lucerne, lettuce, radish, string bean (Phaseolus vulgaris), and cucumber grown in pots in eight Greek soil types in a glasshouse pot experiment in 1989.The CRs of the crops and of the plant parts studied differed according to soil type. They ranged from 0·034–1·39 for wheat grains to 7·6–36·5 for cucumber stems and leaves. The CRs of the edible parts were much lower than those of the other plant material.The correlation between CRs and clay content was negative and, in most cases, significant (P = 0·05–0·01) or highly significant (P < 0·01). The negative correlation improved (higher absolute value of r, lower variability) if clay plus silt content or cation exchange capacity was used instead of clay content.The correlation between CRs and soil properties was greatest for soil pH (r = –0·89) and decreased in the order: pH > total clay plus silt ≃ cation exchange capacity > total clay.

scholarly journals Influence of brick manufacturing on phosphorus and sulfur in different agro-ecological soils of Bangladesh

2017 ◽  
Vol 29 (2) ◽  
pp. 123-131
Author(s):  
Reshma Akter ◽  
Md Jamal Uddin ◽  
Md Faruque Hossain ◽  
Zakia Parveen
Keyword(s):  
Organic Matter ◽  
Cation Exchange ◽  
Soil Ph ◽  
Cation Exchange Capacity ◽  
Clay Content ◽  
Exchange Capacity ◽  
Soil Samples ◽  
Maximum Accumulation ◽  
Brick Kilns ◽  
Total P

A study was carried out to evaluate the effects of brick manufacturing on phosphorus (P) and sulfur (S) concentrations in soil and plant collected from different distances of brick kilns in four AEZs of Bangladesh. Forty eight composite soil samples (0 - 15 cm depth) were collected from 48 points in 12 different sites at 0 m, 300 m, 800 m and 1500 m from brick kilns, where most (site 2, site 3, site 5, site 6, site 7, site 9 and site 10) of the brick kilns used coal for brick burning purposes. Plant samples (rice straw and different vegetables) were also collected from the respective fields except 0 m distances. Significantly (p ? 0.05) lower organic matter, cation exchange capacity, clay content and soil pH were found at 0 m distances compared to other distances. Highest concentration of total P in soil were recorded at 0 m distances and these concentrations decreased with increasing distances from the brick kilns in most of the sites; whereas available P is significantly lower at 0 m distances than that of other distances. Total and available concentration of S in soil followed the trend 0 m>300 m>800 m>1500 m. Maximum accumulation of P (69.15 mg kg-1) and S (0.14%) in plant was found at 800 m away from the brick kiln.Bangladesh J. Sci. Res. 29(2): 123-131, December-2016

scholarly journals Development of a composite soil degradation assessment index for cocoa agroecosystems in southwestern Nigeria

Solid Earth ◽  
2017 ◽  
Vol 8 (4) ◽  
pp. 827-843 ◽  
Author(s):  
Sunday Adenrele Adeniyi ◽  
Willem Petrus de Clercq ◽  
Adriaan van Niekerk
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Soil Properties ◽  
Cation Exchange ◽  
Cation Exchange Capacity ◽  
Soil Degradation ◽  
Clay Content ◽  
Exchange Capacity ◽  
Southwestern Nigeria ◽  
Assessment Index

Abstract. Cocoa agroecosystems are a major land-use type in the tropical rainforest belt of West Africa, reportedly associated with several ecological changes, including soil degradation. This study aims to develop a composite soil degradation assessment index (CSDI) for determining the degradation level of cocoa soils under smallholder agroecosystems of southwestern Nigeria. Plots where natural forests have been converted to cocoa agroecosystems of ages 1–10, 11–40, and 41–80 years, respectively representing young cocoa plantations (YCPs), mature cocoa plantations (MCPs), and senescent cocoa plantations (SCPs), were identified to represent the biological cycle of the cocoa tree. Soil samples were collected at a depth of 0 to 20 cm in each plot and analysed in terms of their physical, chemical, and biological properties. Factor analysis of soil data revealed four major interacting soil degradation processes: decline in soil nutrients, loss of soil organic matter, increase in soil acidity, and the breakdown of soil textural characteristics over time. These processes were represented by eight soil properties (extractable zinc, silt, soil organic matter (SOM), cation exchange capacity (CEC), available phosphorus, total porosity, pH, and clay content). These soil properties were subjected to forward stepwise discriminant analysis (STEPDA), and the result showed that four soil properties (extractable zinc, cation exchange capacity, SOM, and clay content) are the most useful in separating the studied soils into YCP, MCP, and SCP. In this way, we have sufficiently eliminated redundancy in the final selection of soil degradation indicators. Based on these four soil parameters, a CSDI was developed and used to classify selected cocoa soils into three different classes of degradation. The results revealed that 65 % of the selected cocoa farms are moderately degraded, while 18 % have a high degradation status. The numerical value of the CSDI as an objective index of soil degradation under cocoa agroecosystems was statistically validated. The results of this study reveal that soil management should promote activities that help to increase organic matter and reduce Zn deficiency over the cocoa growth cycle. Finally, the newly developed CSDI can provide an early warning of soil degradation processes and help farmers and extension officers to implement rehabilitation practices on degraded cocoa soils.

scholarly journals Characteristics of Soils Developing from Gabbro, Phyllite and Chert Parent Rock in Karangsambung District

2019 ◽  
Vol 4 (3) ◽  
pp. 131
Author(s):  
Ratna Taher ◽  
Makruf Nurudin ◽  
Eko Hanudin
Keyword(s):  
Cation Exchange ◽  
Cation Exchange Capacity ◽  
Particle Density ◽  
Chemical Properties ◽  
Clay Content ◽  
Exchange Capacity ◽  
Parent Rock ◽  
Soil Morphology ◽  
Total N ◽  
Organic C

Understanding the nature of the soil is very important to know the potential and the proper management of the soil. This study aimed to determine the differences in morphological, physical, and chemical properties of the soils developing from gabbro, phylitte and chert parent materials. The soil profile was made to represent each parent rock of gabbro, phyllite and chert located on the upper and middle slopes with pine-dominated vegetation and mixed gardens. Observation in the field is a professional description to observe soil morphology. Soil samples were taken at each horizon to analyze soil physical properties (bulk density, particle density, and texture), soil chemical properties (pH, exchanged cations, cation exchange capacity, available P, organic C, and total N). Texture analysis results showed that clay content of the soil developing from parent rock of Gabro 1 is the highest, followed by the soil clay content from  Chert 1, Phyllite 1, Chert 2, Phyllite 2, and Gabbro 2, respectively. The order of soil acidity level (pH) is Gabbro 2 > Gabbro 1> Chert 1 ~ Chert 2 > Phyllite 1 ~ Phyllite 2. Meanwhile, the order of the cation exchange capacity is Gabbro 1> Gabbro 2> Phyllite 1> Chert 1> Phyllite 2> Chert 2, and the order of the base saturation is Chert 2> Gabbro 2> Chert 1> Phyllite 2 > Phyllite1> Gabbro 1.

scholarly journals Evaluation of the lime requirement of tropical soils in terms of other soil characteristics

1969 ◽  
Vol 36 (2) ◽  
pp. 155-160
Author(s):  
M. A. Lugo López ◽  
F. Abruña ◽  
J. Roldán
Keyword(s):  
Cation Exchange ◽  
Clay Mineral ◽  
Cation Exchange Capacity ◽  
Ph Value ◽  
Organic Matter Content ◽  
Clay Content ◽  
Tropical Soils ◽  
Exchange Capacity ◽  
Matter Content ◽  
Significant Regression

The quantity of limestone required to bring the pH of various acid Puerto Rican soils to 6.5 was investigated and found to vary from several hundred to several thousands pounds per acre. To investigate the relation of clay-mineral type, clay content, cation-exchange capacity, organic-matter content, and pH to lime requirement, these properties were determined for several soils. A highly significant regression of lime requirement on pH was obtained which can be expressed by the equation: Y = 18.39 — 3.196 X, where Y is the lime requirement and X is the pH value. Multiple regressions including other factors did not significantly increase the variability which could be explained on terms of the first regression. Further analysis were made by arranging the data according to the predominant clay mineral. For kaolinitic soils highly significant correlations were obtained between lime requirement and either pH or cation exchange capacity. The regressions were: (a) Y = 15.26 — 2.632 pH, and (b) Y = 3.048 + 0.5774 (cation-exchange capacity), where Y is the lime requirement. A regression of lime requirement on both factors did not significantly increase the variability explained by the second equation. No significant regressions were obtained for beidellitic soils.

scholarly journals Color parameters applied to pedotransfer functions in the estimation of soil attributes

2018 ◽  
Vol 39 (4) ◽  
pp. 1479
Author(s):  
Nara Núbia de Lima Cruz ◽  
Ronny Sobreira Barbosa ◽  
Marcio Cleto Soares de Moura ◽  
Daniel De Bortoli Teixeira ◽  
José Marques Júnior ◽  
...  
Keyword(s):  
Cation Exchange ◽  
Cation Exchange Capacity ◽  
Diffuse Reflectance ◽  
Diffuse Reflectance Spectroscopy ◽  
Clay Content ◽  
Exchange Capacity ◽  
Pedotransfer Functions ◽  
Soil Attributes ◽  
Color System ◽  
Potential Acidity

Global demands for an increased food production have prompted scientists to create technological innovations in various segments of the agricultural and environmental sectors. The use of diffuse reflectance spectroscopy in soil color determination to estimate its attributes is an example of these advances. Thus, the aim of this research was to identify the potential of the three parameters of the Munsell color system (Hue, Value, and Chroma) in estimating different chemical and particle size attributes by pedotransfer functions in a Typic Hapludox in the Cerrado of Piauí State, Brazil. This soil showed a yellowish color due to the goethite and low contents of bases and organic carbon. Among the calibrated pedotransfer functions, we observed that phosphorus, aluminum, hydrogen, potential acidity, potential cation exchange capacity, and base saturation could be estimated by Hue, while clay content by Value, and Chroma used to estimate hydrogen, potential acidity, and cation exchange capacity. We conclude that the parameter color could be used to estimate soil attributes.

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