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.

Damage to soil physical properties caused by soil sampler devices as assessed by gamma ray computed tomography

Soil Research ◽  
2004 ◽  
Vol 42 (7) ◽  
pp. 857 ◽  
Author(s):  
Luiz F. Pires ◽  
Osny O. S. Bacchi ◽  
Klaus Reichardt
Keyword(s):  
Computed Tomography ◽  
Physical Properties ◽  
Bulk Density ◽  
Soil Sample ◽  
First Generation ◽  
Gamma Ray ◽  
Soil Bulk Density ◽  
241Am Source ◽  
Sampling Procedures ◽  
Gamma Ray Computed Tomography

Soil sample physical properties can be greatly affected during soil sampling procedures. Improper procedures can impose modifications on soil sample structure and consequently lead to wrong measurements of soil properties. The objective of this work was to evaluate the damage caused by soil samplers to soil structure through the analysis of computed tomography (CT) images. A first generation tomograph was used, having a 241Am source and a 7.62 × 7.62 cm NaI(Tl) scintillation crystal detector coupled to a photomultiplier tube. Results confirm the effect of soil sampler devices on the structure of soil samples, and that the compaction caused during sampling causes significant alterations to soil bulk density. Through the use of CT it was possible to determine the level of compaction and to make a detailed analysis of the soil bulk density distribution within the soil sample.

scholarly journals Machine-Learning Classification of Soil Bulk Density in Salt Marsh Environments

Sensors ◽  
2021 ◽  
Vol 21 (13) ◽  
pp. 4408
Author(s):  
Iman Salehi Hikouei ◽  
S. Sonny Kim ◽  
Deepak R. Mishra
Keyword(s):  
Machine Learning ◽  
Remote Sensing ◽  
Salt Marsh ◽  
Bulk Density ◽  
Remote Sensing Data ◽  
Soil Bulk Density ◽  
Soil Samples ◽  
Marsh Soil ◽  
Landsat 7 ◽  
Salt Marsh Soil

Remotely sensed data from both in situ and satellite platforms in visible, near-infrared, and shortwave infrared (VNIR–SWIR, 400–2500 nm) regions have been widely used to characterize and model soil properties in a direct, cost-effective, and rapid manner at different scales. In this study, we assess the performance of machine-learning algorithms including random forest (RF), extreme gradient boosting machines (XGBoost), and support vector machines (SVM) to model salt marsh soil bulk density using multispectral remote-sensing data from the Landsat-7 Enhanced Thematic Mapper Plus (ETM+) platform. To our knowledge, use of remote-sensing data for estimating salt marsh soil bulk density at the vegetation rooting zone has not been investigated before. Our study reveals that blue (band 1; 450–520 nm) and NIR (band 4; 770–900 nm) bands of Landsat-7 ETM+ ranked as the most important spectral features for bulk density prediction by XGBoost and RF, respectively. According to XGBoost, band 1 and band 4 had relative importance of around 41% and 39%, respectively. We tested two soil bulk density classes in order to differentiate salt marshes in terms of their capability to support vegetation that grows in either low (0.032 to 0.752 g/cm3) or high (0.752 g/cm3 to 1.893 g/cm3) bulk density areas. XGBoost produced a higher classification accuracy (88%) compared to RF (87%) and SVM (86%), although discrepancies in accuracy between these models were small (<2%). XGBoost correctly classified 178 out of 186 soil samples labeled as low bulk density and 37 out of 62 soil samples labeled as high bulk density. We conclude that remote-sensing-based machine-learning models can be a valuable tool for ecologists and engineers to map the soil bulk density in wetlands to select suitable sites for effective restoration and successful re-establishment practices.

Forest Soil Compaction: Effect of Multiple Passes and Loadings on Wheel Track Surface Soil Bulk Density

1988 ◽  
Vol 5 (2) ◽  
pp. 120-123 ◽  
Author(s):  
Stephen G. Shetron ◽  
John A. Sturos ◽  
Eunice Padley ◽  
Carl Trettin
Keyword(s):  
Bulk Density ◽  
Soil Compaction ◽  
Surface Soil ◽  
Soil Bulk Density ◽  
Northern Red Oak ◽  
Wheel Drive ◽  
Density Values ◽  
Track Surface ◽  
Four Wheel Drive ◽  
Wheel Track

Abstract The change in wheel track surface soil bulk densities was determined after a mechanized thinning in a northern red oak stand. Mean bulk density values of the 0 to 5 cm surface of the wheel tracks immediately after felling, bunching, and skidding were: 0.80 g/cc on the high use areas; 0.77 g/cc on the low use areas; and 0.42 g/cc in the undisturbed areas. No significant differences in surface soil bulk densities were found between several loading treatments using a four-wheel drive articulated forwarder. The data indicate that initial passes of the equipment produce most of the disturbance. No significant recovery in wheel track soil bulk densities occurred during the year following harvest regardless of treatment. North. J. Appl. For. 5:120-123, June 1988.

DEVELOPMENT OF COMPACTION PATTERNS DUE TO MACHINERY OPERATION IN AN ORCHARD SOIL

1976 ◽  
Vol 56 (3) ◽  
pp. 505-509 ◽  
Author(s):  
G. S. V. RAGHAVAN ◽  
E. MCKYES ◽  
M. CHASSÉ ◽  
F. MÉRINEAU
Keyword(s):  
Bulk Density ◽  
Gamma Ray ◽  
Soil Bulk Density ◽  
Soil Conditions ◽  
Soil Density ◽  
Compaction Test ◽  
Orchard Soil ◽  
Ray Density

A series of tests was performed in a field, freshly prepared and ready for the planting of new trees, to study the pattern of soil density changes under different loads, soil conditions, tire sizes and numbers of passes using a gamma-ray density meter. The change in soil bulk density varied from 0.08 g/cc to 0.48 g/cc for increasing numbers of traverses of tractor and sprayer. The soil bulk density achieved after 15 passes with a tractor and sprayer approximated both the maximum bulk density obtained with a standard Proctor compaction test and the maximum bulk density that has been observed in adjacent orchards that are 30–40 yr old.

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