scholarly journals Gamma-Ray Attenuation to Evaluate Soil Porosity: An Analysis of Methods

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Luiz F. Pires ◽  
André B. Pereira
Keyword(s):  
Gamma Ray ◽  
Particle Density ◽  
Pore Space ◽  
Physical Property ◽  
Soil Bulk Density ◽  
Soil Porosity ◽  
Porous System ◽  
Soil Pore Space ◽  
Gamma Ray Attenuation ◽  
Dry Soil

Soil porosity (ϕ) is of a great deal for environmental studies due to the fact that water infiltrates and suffers redistribution in the soil pore space. Many physical and biochemical processes related to environmental quality occur in the soil porous system. Representative determinations ofϕare necessary due to the importance of this physical property in several fields of natural sciences. In the current work, two methods to evaluateϕwere analyzed by means of gamma-ray attenuation technique. The first method uses the soil attenuation approach through dry soil and saturated samples, whereas the second one utilizes the same approach but taking into account dry soil samples to assess soil bulk density and soil particle density to determineϕ. The results obtained point out a good correlation between both methods. However, whenϕis obtained through soil water content at saturation and a 4 mm collimator is used to collimate the gamma-ray beam the first method also shows good correlations with the traditional one.

scholarly journals Representative Elementary Length to Measure Soil Mass Attenuation Coefficient

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
J. A. R. Borges ◽  
L. F. Pires ◽  
J. C. Costa
Keyword(s):  
Attenuation Coefficient ◽  
Gamma Ray ◽  
Clayey Soil ◽  
Physical Property ◽  
Soil Mass ◽  
Mass Attenuation Coefficient ◽  
Soil Bulk Density ◽  
Elementary Length ◽  
Increasing Demand ◽  
Mass Attenuation

With increasing demand for better yield in agricultural areas, soil physical property representative measurements are more and more essential. Nuclear techniques such as computerized tomography (CT) and gamma-ray attenuation (GAT) have been widely employed with this purpose. The soil mass attenuation coefficient (μs) is an important parameter for CT and GAT analysis. When experimentally determined (μes), the use of suitable sized samples enable to evaluate it precisely, as well as to reduce measurement time and costs. This study investigated the representative elementary length (REL) of sandy and clayey soils forμesmeasurements. Two radioactive sources were employed (241Am and137Cs), three collimators (2–4 mm diameters), and 14 thickness (x) samples (2–15 cm). Results indicated ideal thickness intervals of 12–15 and 2–4 cm for the sources137Cs and241Am, respectively. The application of such results in representative elementary area (REA) evaluations in clayey soil clods via CT indicated thatμesaverage values obtained forx > 4 cm and source241Am might induce to the use of samples which are not large enough for soil bulk density evaluations (ρs). As a consequence,ρsmight be under- or overestimated, generating inaccurate conclusions about the physical quality of the soil under study.

Gamma-ray attenuation method as an efficient tool to investigate soil bulk density spatial variability

2009 ◽  
Vol 36 (11-12) ◽  
pp. 1734-1739 ◽  
Author(s):  
L.F. Pires ◽  
J.A. Rosa ◽  
A.B. Pereira ◽  
R.C.J. Arthur ◽  
O.O.S. Bacchi
Keyword(s):  
Spatial Variability ◽  
Bulk Density ◽  
Gamma Ray ◽  
Soil Bulk Density ◽  
Efficient Tool ◽  
Gamma Ray Attenuation

scholarly journals Compost-Containing Substrates and Their Effect on Posttransplant Growth of Containerized Tree Seedlings

2006 ◽  
Vol 32 (6) ◽  
pp. 289-296
Author(s):  
Bruce Roberts
Keyword(s):  
Physical Properties ◽  
Sugar Maple ◽  
Particle Density ◽  
Pore Space ◽  
Soil Bulk Density ◽  
Tree Seedlings ◽  
Total Biomass ◽  
Green Ash ◽  
Red Maple ◽  
Biosolid Compost

Greenhouse studies were undertaken to determine the influence of composted media on the posttransplant growth of containerized red maple, sugar maple, and green ash seedlings. Before planting, the chemical and physical properties of each substrate were measured. For media containing composted biosolids, pH was significantly higher, whereas electrical conductivity, air-filled porosity, and total pore space were significantly lower than in a composted medium without biosolids. For composted substrates containing at least some soil, bulk density, particle density, and container capacity were all significantly greater than for composts without any soil. Growth of red maple was about the same in a noncomposted soilless medium (Metro-mix 360) as it was in substrates containing biosolid compost. Height growth, total biomass, and root biomass of green ash were all significantly greater for seedlings grown in Metro-mix 360 only, and the growth of sugar maple seedlings was about the same in Metro-mix 360 or in a composted substrate without biosolids (Metro-mix 560). The results of this study suggest no particular short-term growth advantage of using composted media as backfill amendments when transplanting; however, the addition of composts could be beneficial in improving the chemical and physical properties of native soils, particularly urban soils containing very low levels of organic matter.

Computation of hydraulic conductivity of porous materials using computer-assisted tomography

Soil Research ◽  
1996 ◽  
Vol 34 (5) ◽  
pp. 671 ◽  
Author(s):  
VK Phogat ◽  
LAG Aylmore
Keyword(s):  
Spatial Distribution ◽  
Hydraulic Conductivity ◽  
Glass Bead ◽  
Gamma Ray ◽  
Pore Space ◽  
Empirical Relationship ◽  
Soil Aggregate ◽  
Computer Assisted ◽  
Computer Assisted Tomography ◽  
Gamma Ray Attenuation

The spatial distribution of porosity and continuity of pore space in glass bead and soil aggregate systems has been characterised by application of computer-assisted tomography to gamma-ray attenuation measurements. It has been demonstrated that a useful empirical relationship between hydraulic conductivity and pore size and continuity for the glass bead system as measured by CAT scanning can be derived.

scholarly journals Perbaikan Sifat Fisik Tanah Inceptisol dan Pertumbuhan Tanaman Jagung (Zea mays L.) akibat Pemberian Kompos Granul Ela Sagu dan Pupuk Fosfat

2021 ◽  
Vol 2 (1) ◽  
pp. 236-252
Author(s):  
Maimuna La Habi ◽  
Aminudin Umasangaji
Keyword(s):  
Zea Mays ◽  
Bulk Density ◽  
Zea Mays L ◽  
Particle Density ◽  
Soil Bulk Density ◽  
Soil Porosity ◽  
Soil P ◽  
Available Water ◽  
Total Soil

Percobaan pot di rumah kaca dirancang untuk mengetahui pengaruh kompos granular limbah empulur sagu dan pupuk fosfat terhadap peningkatan karakteristik fisik Inceptisols dan pertumbuhan jagung. Percobaan menggunakan Rancangan Acak Lengkap faktorial 3 x 3 dengan 3 ulangan. Faktor pertama adalah KGES 0 (tanpa kompos granul ampas sagu), KGES 1 (100 g.pot-1), dan KGES 2 (200 g.pot-1) berupa kompos granul limbah empulur sagu; faktor kedua adalah pupuk P0 (tanpa fosfat), P1 (0,326 g.pot-1) dan P2 (0,652 g.pot-1). Hasil percobaan menunjukkan bahwa pemberian kompos granular limbah empulur sagu dan pupuk fosfor berpengaruh nyata terhadap soil bulk density, particle density, soil porosity, fast drainage pores, slow drainage pores, available water pores, unavailable water pores, total soil-P, dan tinggi tanaman. Sedangkan pupuk fosfor tidak berpengaruh nyata terhadap soil bulk density, porosity, slow drainage pores, unavailable water pores, dan tinggi tanaman.

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