scholarly journals Extractable zinc in particle size fractions of soils from Western-Australia and Queensland

Soil Research ◽  
1990 ◽  
Vol 28 (3) ◽  
pp. 387 ◽  
Author(s):  
JD Armour ◽  
GSP Ritchie ◽  
AD Robson
Keyword(s):  
Particle Size ◽  
Organic Carbon ◽  
Western Australia ◽  
Ammonium Oxalate ◽  
Clay Fraction ◽  
Coarse Sand ◽  
Clay Soils ◽  
Size Fractions ◽  
Particle Size Fractions ◽  
Zn Content

The zinc (Zn) content of particle size fractions of 12 mainly Zn deficient soils was measured by extraction with three contrasting extractants. The soils, which ranged from sands to a black earth, were from Western Australia and Queensland and particle size fractions (clay, silt, fine sand, coarse sand) were obtained by sieving and sedimentation after ultrasonification of soil suspended in deionized water. The extractants were concentrated HNO3/H2SO4/HClO4 (acid extractable or AE-Zn), DTPA and 0.002 M CaCl2. For each extractant, Zn contents of the fractions and whole soils were correlated with organic carbon and ammonium oxalate extractable Fe and Al. The AE-Zn concentrations in whole soils were 0.6-132 mg kg-1 and high clay soils had higher concentrations (mean 54 mg kg-1) than low clay soils (mean 2 mg kg-1). After fractionation, lowest AE- and DTPA-Zn were found in coarse sand fractions and concentrations increased with decreasing particle size. Clay plus silt fractions contained 60-99% of the whole soil AE-Zn and 76-93% of the whole soil DTPA-Zn. The CaCl2-Zn concentrations were very low (<5.0 �g kg-1) for all soils. In whole soils, DTPA-Zn was only a small proportion, 3.2% and 1.8%, of the AE-Zn in the low clay and high clay soils, respectively. The CaCl2-Zn was generally less than 2% of the DTPA-Zn in whole soils. In whole soils, AE-Zn was correlated with oxalate extractable Fe and with oxalate A1 (r = 0.72 and 0.71, respectively; P <0.01), whereas DTPA-Zn was correlated with oxalate extractable Fe (r = 0.82; P < 0.01). The AE- and DTPA-Zn were correlated with organic carbon only in some fractions. The DTPA- and CaCl2-Zn were not correlated with AE-Zn content, nor was DPTA-Zn correlated with CaCl2-Zn in whole soils or fractions (P<0.05). Dispersion of the soils with ultrasonification in the absence of dispersing agents was not as effective as dispersion with conventional mechanical/chemical dispersion. The percentage of the soil recovered in the clay fraction after sonification was 23-78% of that recovered by the conventional method. Fine and coarse sand contents were similar for either method, indicating that incomplete dispersion of clay by ultrasonification resulted in higher silt contents.

scholarly journals PROBABILITY OF PARTICLE-SIZE FRACTIONS OCCURRENCE IN DIFFERENT LANDFORMS

2018 ◽  
Vol 26 (4) ◽  
pp. 352-359
Author(s):  
Julião Soares de Souza Lima ◽  
Samuel Assis Silva ◽  
Daniel Pena Pereira ◽  
Marcelo Soares Altoé
Keyword(s):  
Particle Size ◽  
Clay Fraction ◽  
Spherical Model ◽  
Fine Sand ◽  
Coarse Sand ◽  
Indicator Kriging ◽  
Size Fractions ◽  
Particle Size Fractions ◽  
Probability Of Occurrence ◽  
Present Pattern

Knowing the variation of particle-size fractions, considering the relief forms, contributes for understanding the variation of other soil attributes. This work aimed to study the spatial distribution of the probability of particle-size fractions occurrence (clay, silt, very fine sand, fine sand, coarse sand, and total sand) in a clayey Oxisol with predominance of concave and convex curvatures. A sampling grid with 94 sampling points in 33x33m spacing at a depth of 0–0.20 m was built using a GPS. The spatial analysis was performed through indicator kriging. The spherical model was fit for all soil fractions, with ranges varying from 130 m to 280 m. In the region of convex curvature, the clay fraction presented the highest probability of occurrence (0.75 to 1.00), whereas in the concave region the coarse sand and total sand fractions presented the highest probability of occurrence. The very fine sand fraction and the silt did not present pattern of distribution in relation to the dominant curvatures of the relief.

scholarly journals Long term trends in fertility of soils under continuous cultivation and cereal cropping in southern Queensland. III. Distribution and kinetics of soil organic carbon in particle size fractions

Soil Research ◽  
1986 ◽  
Vol 24 (2) ◽  
pp. 293 ◽  
Author(s):  
RC Dalal ◽  
RJ Mayer
Keyword(s):  
Particle Size ◽  
Organic Matter ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Size Fraction ◽  
Organic C ◽  
Size Fractions ◽  
Particle Size Fractions ◽  
Clay Size Fraction ◽  
Sand Size

Distribution of soil organic carbon in sand-, silt- and clay-size fractions during cultivation for periods ranging from 20 to 70 years was studied in six major soils used for cereal cropping in southern Queensland. Particle-size fractions were obtained by dispersion in water using cation exchange resin, sieving and sedimentation. In the soils' virgin state no single particle-size fraction was found to be consistently enriched as compared to the whole soil in organic C in all six soils, although the largest proportion (48%) of organic C was in the clay-size fraction; silt and sand-size fractions contained remaining organic C in equal amounts. Upon cultivation, the amounts of organic C declined from all particle-size fractions in most soils, although the loss rates differed considerably among different fractions and from the whole soil. The proportion of the sand-size fraction declined rapidly (from 26% to 12% overall), whereas that of the clay-size fraction increased from 48% to 61% overall. The proportion of silt-size organic C was least affected by cultivation in most soils. It was inferred, therefore, that the sand-size organic matter is rapidly lost from soil, through mineralization as well as disintegration into silt-size and clay-size fractions, and that the clay fraction provides protection for the soil organic matter against microbial and enzymic degradation.

scholarly journals Spatial variability of particle size fractions of an Oxisol cultivated with conilon coffee

Revista CERES ◽  
2012 ◽  
Vol 59 (6) ◽  
pp. 867-872 ◽  
Author(s):  
Julião Soares de Souza Lima ◽  
Rone Batista de Oliveira ◽  
Samuel de Assis Silva
Keyword(s):  
Particle Size ◽  
Spatial Variability ◽  
Clay Fraction ◽  
Soil Samples ◽  
Landscape Configuration ◽  
Sand Fraction ◽  
Size Fractions ◽  
Particle Size Fractions ◽  
Average Value ◽  
Significant Difference

Information on the spatial distribution of particle size fractions is essential for use planning and management of soils. The aim of this work to was to study the spatial variability of particle size fractions of a Typic Hapludox cultivated with conilon coffee. The soil samples were collected at depths of 0-0.20 and 0.20-0.40 m in the coffee canopy projection, totaling 109 georeferentiated points. At the depth of 0.2-0.4 m the clay fraction showed average value significantly higher, while the sand fraction showed was higher in the depth of 0-0.20 m. The silt showed no significant difference between the two depths. The particle size fractions showed medium and high spatial variability. The levels of total sand and clay have positive and negative correlation, respectively, with the altitude of the sampling points, indicating the influence of landscape configuration.

STUDIES ON THE DYNAMICS OF "RECENTLY" CLAY-FIXED NH4+ USING 15N

1980 ◽  
Vol 60 (1) ◽  
pp. 61-70 ◽  
Author(s):  
C. G. KOWALENKO ◽  
G. J. ROSS
Keyword(s):  
Particle Size ◽  
Clay Fraction ◽  
Extraction Methods ◽  
Size Fractions ◽  
Particle Size Fractions ◽  
Fine Clay ◽  
Tracer Methods ◽  
Field And Laboratory Conditions ◽  
The Relationship ◽  
Fast Release

The dynamics of fixation and release of NH4+ in soils were studied using tracer N under field and laboratory conditions. Field data showed that release of fixed NH4+ was relatively slow after an initial moderately fast release. Forty months of field weathering of Bainsville soil left 3.48 kg 15N/ha in the 75-cm profile of the 13.5 kg 15N/ha applied and most (76%) of this recovered 15N was fixed NH4+–N. The relative quantitative importance of recently fixed NH4+ in the various particle size fractions was not in the same order as the native fixed NH4+. The fine silt fraction (2–5 μm) fixed a larger amount (whole soil basis) than the fine clay fraction (< 0.2 μm). The coarse clay fraction (0.2–2 μm) fixed the most NH4+ added as well as being the fraction containing the most native fixed NH4+. Sand size fractions were shown to contain native fixed NH4+ and were capable of fixing a small amount of added NH4+. Measurements of recently fixed NH4+–N in various particle sizes covering four time intervals (up to 40 mo) of field weathering under fallow showed that the 0.2 to 2-μm fraction was quantitatively most important, the < 0.2-μm fraction most readily released recently fixed NH4+ and the 2 to 5-μm fraction was the most stable with respect to recently fixed NH4+. Plant growth affected the relative stability of the recently fixed NH4+ in the various particle size fractions. Laboratory studies of three Brookston soil samples revealed higher estimates of fixation of NH4+ by direct tracer methods than by indirect extraction methods. This discrepancy was assumed to have been caused by some exchange of added NH4+ with native fixed NH4+ and by some NH4+ being fixed on other sites. The relationship between mineralogical and related analyses to fixation of NH4+ was discussed.

scholarly journals Modeling of Permanent Wilting from Particle Size Fractions of Coastal Plain Sands Soils in Southeastern Nigeria

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Chinedu Innocent Obi ◽  
Jude C. Obi ◽  
Emmanuel U. Onweremadu
Keyword(s):  
Particle Size ◽  
Coastal Plain ◽  
Particle Size Analysis ◽  
Coarse Sand ◽  
Size Analysis ◽  
Southeastern Nigeria ◽  
Size Fractions ◽  
Particle Size Fractions ◽  
Permanent Wilting Point ◽  
Wilting Point

Permanent wilting points in soils have been found to correlate significantly with particle size fractions. This study was conducted to establish functional relationship between soil particle size fractions and permanent wilting point of soils of coastal plain sands in southeastern Nigeria. A total of 102 surface samples were collected from three different dominantly Ultisols toposequences (i.e., 34 samples from each). Permanent wilting point experiment was carried out in pots with the 102 samples in the greenhouse while the particle size analysis was carried out in the laboratory. There was significant correlation among the textural separates, permanent wilting point correlated significantly with clay (, ). The general linear model showed significant differences between permanent wilting point of soils found in the upper and lower slope positions. Regression equation established that 54% of the total variation in permanent wilting point could be accounted for by the clay and coarse sand content of the soils. Prediction of permanent wilting point of Ultisols formed on coastal plain sands soils of humid tropical southeastern Nigeria will effectively depend on reliability of determination of clay and coarse sand contents of the soils.

scholarly journals Potassium status in different particle size fractions of some Finnish soils

1967 ◽  
Vol 39 (2) ◽  
pp. 45-56
Author(s):  
Armi Kaila
Keyword(s):  
Particle Size ◽  
Organic Matter ◽  
Fine Sand ◽  
Clay Soils ◽  
Size Fractions ◽  
Particle Size Fractions

Samples of fine sand, silt and clay soils from the surface and the deeper layers were separated without destruction of organic matter into the following fractions: clay

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.

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