scholarly journals Boron Characterization, Distribution in Particle-Size Fractions, and Its Adsorption-Desorption Process in a Semiarid Tunisian Soil

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Ahlem Tlili ◽  
Imene Dridi ◽  
Rafla Attaya ◽  
Moncef Gueddari
Keyword(s):  
Particle Size ◽  
Soil Properties ◽  
Soil Profile ◽  
Boron Deficiency ◽  
Crop Species ◽  
Desorption Process ◽  
Size Fractions ◽  
Particle Size Fractions ◽  
Boron Distribution ◽  
Adsorption Desorption

Boron is essential for crop growth but needed in very small amounts. The range between boron deficiency and toxicity for plants is quite narrow. These stress conditions gravely reduce yield and quality of many crop species. Therefore, understanding the factors and the reactions affecting boron availability in soil is necessary. Against this framework, our research aims to determine the available boron status in a semiarid soil of Dour Ismail irrigated perimeter (North Tunisia). The objectives are also to investigate boron distribution in different particle-size fractions throughout the soil profile and to understand boron adsorption-desorption mechanisms according to some soil properties. For this purpose, one soil profile was dug in the field plot that had not received any previous boron fertilization. Soil samples were gathered from the different horizons of the profile and analyzed for the main physicochemical properties. Our results showed that the studied soil is Stagnic Fluvisol (clayic). The highest boron amounts were recorded in deep horizons and were greatly affected by soil salinity, organic matter, and clay contents. However, the increase in the pH level and the high percentage of total lime significantly diminished the available boron amounts in surface layers. The investigation of depth boron distribution in the different particle-size fractions indicated a considerable contribution of the silt (2–50 µm) fraction (52% of the soil total available boron), while the coarse (>50 µm) and clay (<2 µm) fractions seem to play a less important role. The adsorption data were fitted to Freundlich adsorption isotherm. It revealed that adsorption of boron increased with the increase of boron concentrations in soil solution. Desorption isotherm denotes that the accumulated boron in soil was not easily released. Adsorption and desorption of boron in soil were greatly affected by soil properties, such as pH, salinity, sand content, clay content, total organic carbon, total nitrogen, and cation exchange capacity.

scholarly journals Impact of Texture on Sesquioxide Distribution in Southeastern Nigerian Soils

2019 ◽  
Vol 8 (1) ◽  
pp. 43-58
Author(s):  
Bethel Uzoho ◽  
Nnaemeka Okoli ◽  
Ugochi Ekwugha
Keyword(s):  
Particle Size ◽  
Soil Properties ◽  
Flat Surface ◽  
Soil Particle ◽  
Bulk Soil ◽  
Size Fractions ◽  
Particle Size Fractions ◽  
Soil Particle Size ◽  
Soil Particle Size Fractions ◽  
The Impact

Sesquioxides which play significant roles in soil classification and dominant soil properties vary in soils with particle size fractions. Using randomized complete block design, this study was conducted in the month of June 2018 to evaluate the impact of texture on sesquioxide distribution in humid rainforest soils of Southeastern Nigeria.  Four mini-pedons were dug at four landscape positions (upslope, midslope, downslope and flat surface) and triplicate soil samples taken from 0-20, 20-40 and 40-60 cm depths, summing to total of 36 samples. Crystalline and amorphous Al, Fe, Mn and Si oxides were then determined at a depth of 0-20 cm using Dithionate Citrate Bicarbonate (DCB) and ammonium oxalate reagents. Dithionate and oxalate fractions in bulk soil ranged between 9300-11,400 (Fed), 390-1580 (Feox), 4600-6700 (Ald), 660-890 (Alox), 3300-5600 (Mnd), 350-580 (Mnox) and 9600-13,500 (Sid) and 1690-1790 mg kg-1 (Siox), with dithionate superior indicating high crystallinity and low mobility of the sesquioxides. Ratios of bulk soil oxalate/dithionate fractions were low and ranged between 0.04-0.17 (Feox/Fed), 0.11-0.15 (Alox/Ald), 0.10-0.16(Mnox/Mnd) and 0.13-0.18 (Siox/Sid) and confirming their crystallinity. Low Feox/Fed ratios signified that soils were well drained (< 0.35), old (< 0.65) and highly weathered (< 0.50) with the order being a decreasing sequence of upslope > flat surface > down slope > midslope. Sesquioxide contents and reactivity in soil particle size fractions (sand, silt and clay) varied with landscapes. Regression models indicated that particle size fractions accounted for 50% of 2/3rd of the bulk soil sesquioxide concentrations and that averaged over landscapes, sand fraction was more enriched with various sesquioxides than the other soil particle size fractions. Correlations between most bulk soil sesquioxide fractions and sesquioxide fractions with selected soil properties (sand, silt, clay, moisture content, total porosity, organic matter, pH, Ca and ECEC) were significant (P < 0.05). 

Distribution of Organic Matter in the Particle Size Fractions of Lateritic Soil (Plinthosol)

2012 ◽  
Vol 63 (4) ◽  
pp. 9-15 ◽  
Author(s):  
Zygmunt Brogowski ◽  
Wojciech Kwasowski
Keyword(s):  
Particle Size ◽  
Organic Matter ◽  
Organic Compounds ◽  
Soil Profile ◽  
Clay Fraction ◽  
Basaltic Rock ◽  
Lateritic Soil ◽  
Size Fractions ◽  
Particle Size Fractions ◽  
Opposite Trend

Abstract The distribution of organic matter in the genetic horizons of lateritic soil within a 100-cm profile to the basaltic parent rock is almost except for horizon Ap. Assuming that the sum of organic matter in 100 cm of the soil profile is 100%, 25.7% of these compounds occur in horizon Ap, whereas in the remaining horizons this value varies within 18-19.2%. In all size fractions, except the clay fraction in diameter of <0.002 mm, the content of organic matter decreases to a certain depth, and increases again in the deepest horizon located directly on the solid basaltic rock. The clay fraction displays an opposite trend; the content of organic matter in them increases with depth. In the horizon at the depth of 60-80 cm, the clay fraction <0.002 mm accumulates half of the total sum of organic compounds of all the remaining fractions. Such distribution of organic matter in soil and among its particle size probably results from the character of the basaltic weathered debris, as well as climate and vegetation covering the studied area.

scholarly journals Mapping soil carbon, particle-size fractions, and water retention in tropical dry forest in Brazil

2016 ◽  
Vol 51 (9) ◽  
pp. 1371-1385 ◽  
Author(s):  
Gustavo Mattos Vasques ◽  
Maurício Rizzato Coelho ◽  
Ricardo Oliveira Dart ◽  
Ronaldo Pereira Oliveira ◽  
Wenceslau Geraldes Teixeira
Keyword(s):  
Particle Size ◽  
Soil Properties ◽  
Ordinary Kriging ◽  
Water Retention ◽  
Tropical Dry Forest ◽  
Forest Area ◽  
Dry Forest ◽  
Organic Carbon Content ◽  
Size Fractions ◽  
Particle Size Fractions

Abstract The objective of this work was to compare ordinary kriging with regression kriging to map soil properties at different depths in a tropical dry forest area in Brazil. The 11 soil properties evaluated were: organic carbon content and stock; bulk density; clay, sand, and silt contents; cation exchange capacity; pH; water retention at field capacity and at permanent wilting point; and available water. Samples were taken from 327 sites at 0.0-0.10, 0.10-0.20, and 0.20-0.40-m depths, in a tropical dry forest area of 102 km2. Stepwise linear regression models for particle-size fractions and water retention properties had the best fit. Relief and parent material covariates were selected in 31 of the 33 models (11 properties at three depths) and vegetation covariates in 29 models. Based on external validation, ordinary kriging obtained higher accuracy for 21 out of 33 property x depth combinations, indicating that the inclusion of a linear trend model before kriging does not necessarily improve predictions. Therefore, for similar studies, the geostatistical methods employed should be compared on a case-by-case basis.

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
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