Effect of collimator size and absorber thickness on soil bulk density evaluation by gamma-ray attenuation

2014 ◽  
Vol 95 ◽  
pp. 333-335 ◽  
Author(s):  
J.C. Costa ◽  
J.A.R. Borges ◽  
L.F. Pires
Keyword(s):  
Bulk Density ◽  
Gamma Ray ◽  
Soil Bulk Density ◽  
Absorber Thickness ◽  
Density Evaluation ◽  
Gamma Ray Attenuation

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

Soil bulk density evaluation by conventional and nuclear methods

Soil Research ◽  
2005 ◽  
Vol 43 (1) ◽  
pp. 97 ◽  
Author(s):  
L. C. Timm ◽  
L. F. Pires ◽  
K. Reichardt ◽  
R. Roveratti ◽  
J. C. M. Oliveira ◽  
...  
Keyword(s):  
Bulk Density ◽  
Gamma Ray ◽  
Soil Bulk Density ◽  
Soil Samples ◽  
Soil Science ◽  
Tukey Test ◽  
Nuclear Methods ◽  
Density Values ◽  
Density Evaluation ◽  
Gamma Ray Computed Tomography

Among the methods used to measure soil bulk density, the following have been prominent: paraffin sealed clod (PS), volumetric ring (VR), and the modern methods like gamma ray computed tomography (GCT) and the neutron/gamma surface gauge (SG). The objective of this work was to compare soil bulk density values obtained through these methods, with the aim of assisting researchers on the choice of the more appropriate method. For this, a 200-m spatial transect was chosen in an experimental area cultivated with coffee, belonging to ESALQ/USP, Piracicaba, SP, Brazil. The SG readings were first taken in the field and thereafter soil samples were collected at 8 different points, spaced at 25 m, for the other methods. The lowest values of soil bulk density were obtained for the SG method (average 1.468 g/cm3) and the highest for the PS (average 1.685 g/cm3), which was similar to the GCT method (average 1.684 g/cm3). The average soil bulk density for the VR method, which has been used in soil science as a standard method, was 1.544 g/cm3. The Tukey test indicates that the PS and GCT methods do not differ significantly (P > 0.05). They do differ in comparison with VR and SG, which also do not differ among themselves.

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.

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