Distribution of organic 14C and 15N in particle-size fractions of soils incubated with 14C, 15N-labelled glucose/NH4, and legume and wheat straw residues

1996 ◽  
Vol 28 (7) ◽  
pp. 893-905 ◽  
Author(s):  
J.N. Ladd ◽  
M. Van Gestel ◽  
L. Jocteur Monrozier ◽  
M. Amato
Keyword(s):  
Particle Size ◽  
Wheat Straw ◽  
Size Fractions ◽  
Particle Size Fractions

Structural Characterization of Soil Organic Matter and Humic Acids in Particle-Size Fractions of an Agricultural Soil

2002 ◽  
Vol 66 (1) ◽  
pp. 129 ◽  
Author(s):  
Benny Chefetz ◽  
Jorge Tarchitzky ◽  
Ashish P. Deshmukh ◽  
Patrick G. Hatcher ◽  
Yona Chen
Keyword(s):  
Particle Size ◽  
Organic Matter ◽  
Soil Organic Matter ◽  
Humic Acids ◽  
Structural Characterization ◽  
Agricultural Soil ◽  
Size Fractions ◽  
Particle Size Fractions

Digital soil mapping of compositional particle-size fractions using proximal and remotely sensed ancillary data

Geophysics ◽  
2012 ◽  
Vol 77 (4) ◽  
pp. WB201-WB211 ◽  
Author(s):  
S. Buchanan ◽  
J. Triantafilis ◽  
I. O. A. Odeh ◽  
R. Subansinghe
Keyword(s):  
Particle Size ◽  
High Resolution ◽  
Soil Mapping ◽  
Additive Models ◽  
Digital Soil Mapping ◽  
Unbiased Estimation ◽  
Ancillary Data ◽  
Size Fractions ◽  
Particle Size Fractions ◽  
Log Ratio

The soil particle-size fractions (PSFs) are one of the most important attributes to influence soil physical (e.g., soil hydraulic properties) and chemical (e.g., cation exchange) processes. There is an increasing need, therefore, for high-resolution digital prediction of PSFs to improve our ability to manage agricultural land. Consequently, use of ancillary data to make cheaper high-resolution predictions of soil properties is becoming popular. This approach is known as “digital soil mapping.” However, most commonly employed techniques (e.g., multiple linear regression or MLR) do not consider the special requirements of a regionalized composition, namely PSF; (1) should be nonnegative (2) should sum to a constant at each location, and (3) estimation should be constrained to produce an unbiased estimation, to avoid false interpretation. Previous studies have shown that the use of the additive log-ratio transformation (ALR) is an appropriate technique to meet the requirements of a composition. In this study, we investigated the use of ancillary data (i.e., electromagnetic (EM), gamma-ray spectrometry, Landsat TM, and a digital elevation model to predict soil PSF using MLR and generalized additive models (GAM) in a standard form and with an ALR transformation applied to the optimal method (GAM-ALR). The results show that the use of ancillary data improved prediction precision by around 30% for clay, 30% for sand, and 7% for silt for all techniques (MLR, GAM, and GAM-ALR) when compared to ordinary kriging. However, the ALR technique had the advantage of adhering to the special requirements of a composition, with all predicted values nonnegative and PSFs summing to unity at each prediction point and giving more accurate textural prediction.

CHARACTERIZATION OF PARTICLE SIZE FRACTIONS OF PEAT. AN INTEGRATED BIOLOGICAL, CHEMICAL, AND SPECTROSCOPIC APPROACH

Soil Science ◽  
1992 ◽  
Vol 153 (5) ◽  
pp. 382-396 ◽  
Author(s):  
B O NORDEN ◽  
ELISABET BOHLIN ◽  
MATS NILSSON ◽  
ÅSA ALBANO ◽  
CHRISTINA RÖCKNER
Keyword(s):  
Particle Size ◽  
Size Fractions ◽  
Particle Size Fractions

ANALYSIS OF AIRBORNE PARTICULATE MATTER COLLECTED AFTER AN ERUPTION EPISODE OF THE POPOCATÉPETL VOLCANO

2003 ◽  
Vol 13 (03n04) ◽  
pp. 133-139 ◽  
Author(s):  
F. ALDAPE ◽  
J. FLORES M.
Keyword(s):  
Particle Size ◽  
Particulate Matter ◽  
Mexico City ◽  
Airborne Particulate Matter ◽  
Airborne Particulate ◽  
Size Fractions ◽  
Particle Size Fractions ◽  
Two Samples ◽  
Popocatépetl Volcano ◽  
Popocatepetl Volcano

Samples of airborne particulate matter were collected in four sites along an east-west line from the Popocatépetl volcano after the eruption episode of June 30, 1997. The Popocatépetl volcano, with variable activity since it was known, is currently under low but continuous activity prolonged for almost one decade, with occasional moderate eruption episodes producing mainly fumes, ashes and volcanic dusts. The main objective of this study is to determine whether or not some elements have increased their presence in the atmosphere as a result of the volcanic activity, and also if some others, not usually found in urban aerosols, have appeared because of the same reason. In addition, the information obtained will be a source of scientific data for health risk assessment of the population exposed to volcanic emanations. The sample collection was performed on alternate days from July 10 to August 13 1997 in Puebla and Atlixco in Puebla State. Tlalpan within Mexico City, and Salazar in the State of Mexico. Two samples a day were taken in two periods: 7-19 h and 19-7 h. The samplers separated particles into two particle size fractions. PM25 and PM15. Elemental concentrations were determined by PIXE and the results obtained showed increased concentrations of mainly Ti and Fe in all sampling sites, thus indicating a long range transportation of volcanic dusts in both particle size fractions. Concentrations of Ti were found clearly above the average values of urban areas such as Mexico City, and although this element can be considered of low toxicity, the biological, metabolic and toxic effects on human beings are still under investigation.

Characterization of olive mill wastes composts and their humic acids: stability assessment within different particle size fractions

2013 ◽  
Vol 34 (6) ◽  
pp. 787-797 ◽  
Author(s):  
Saoussan Masmoudi ◽  
Raja Jarboui ◽  
Hafedh El Feki ◽  
Teresa Gea ◽  
Khaled Medhioub ◽  
...  
Keyword(s):  
Particle Size ◽  
Humic Acids ◽  
Stability Assessment ◽  
Size Fractions ◽  
Particle Size Fractions ◽  
Olive Mill Wastes ◽  
Olive Mill
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