X-ray diffraction measurement of the quartz content of clay and silt fractions in soils

Clay Minerals ◽  
1992 ◽  
Vol 27 (1) ◽  
pp. 47-55 ◽  
Author(s):  
M. Hardy
Keyword(s):  
Particle Size ◽  
Size Fraction ◽  
Internal Standard ◽  
Diffraction Measurement ◽  
Particle Sizes ◽  
Quartz Content ◽  
Size Fractions ◽  
Particle Size Fractions ◽  
Calibration Curves ◽  
Fine Quartz

AbstractAn XRD method for measurement of quartz content using ZnO as the internal standard was tested on different particle sizes between 0 and 20 µm. Calibration curves showed a good correlation coefficient for particle-size fractions up to 20 µm; the slope increased for the fractions from 0·7 to 5 µm and was relatively constant for coarser particle sizes. Fine quartz fractions were etched with hydrofluoric acid to remove the surface layer damaged during dry grinding. The use of such etched quartz increased the slopes of the calibration curves for small particle-size fractions and approximated the natural fine quartz fraction much better than the original dry-ground material. The mean of six measurements gave good accuracy provided that the slope of the calibration curve was adjusted for the particular particle-size fraction. This method was used on 0–2 µm, 0–0·2µm and 0·2–2 µm fractions of French silty soils and the results are in agreement with the data from chemical analysis and with the mineralogical interpretation.

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.

ÉTUDE COMPARATIVE DE L'AGRÉGATION ET DE LA MATIÈRE ORGANIQUE ASSOCIÉE AUX FRACTIONS GRANULOMÉTRIQUES DE SEPT SOLS SOUS CULTURE DE MAÏS OU EN PRAIRIE

1990 ◽  
Vol 70 (3) ◽  
pp. 395-402 ◽  
Author(s):  
J. ELUSTONDO ◽  
M. R. LAVERDIÈRE ◽  
D. A. ANGERS ◽  
A. N'DAYEGAMIYE
Keyword(s):  
Particle Size ◽  
Organic Matter ◽  
Size Fraction ◽  
Cropping System ◽  
Clay Content ◽  
Size Fractions ◽  
Particle Size Fractions ◽  
Carbon And Nitrogen ◽  
Water Stable Aggregates ◽  
Continuous Corn

Water-stable aggregation and organic matter associated with particle-size fractions were compared for seven pairs of soils that were either under meadow or continuous corn cropping for more than 5 yr. Soils that have remained under meadow contained 25 and 29% more carbon and nitrogen than those under continuous corn. Carbon contents of the sand- and silt-size fractions were also 61 and 15% higher, respectively, under meadow than under continuous corn. The cropping system had no significant effect on the carbon and nitrogen contents of the clay-size fractions. The amount of water-stable aggregates (> 1 mm) was on average 34% higher in soils under meadow than in soils under corn cropping. Significant correlations were found between water-stable aggregates and total C (r = 0.77) and C in sand-size fraction (r = 0.79). The results also indicate that the beneficial effect of meadow over continuous corn on soil aggregation increases as soil clay content increases. Key words: Aggregation, organic matter, particle-size fractions, corn, meadow

Potential for using soil particle-size data to infer geological parent material in the Sydney Region

Soil Research ◽  
2013 ◽  
Vol 51 (4) ◽  
pp. 301 ◽  
Author(s):  
Margaret R. Donald ◽  
Pamela A. Hazelton ◽  
AnneMarie Clements
Keyword(s):  
Particle Size ◽  
Soil Sample ◽  
Soil Texture ◽  
Compositional Data ◽  
Size Fraction ◽  
Parent Material ◽  
Ecological Communities ◽  
Size Fractions ◽  
Particle Size Fractions ◽  
Statistical Classifiers

Ecological communities are more than assemblages of species. In assessing the presence of many ecological communities, interpretation of soil properties and associated parent material has become a definitive component under environmental legislation worldwide, and particularly in Australia. The hypothesis tested here is that the geological parent material of a soil sample can be determined from particle size fraction data of the Marshall soil texture diagram. Supervised statistical classifiers were built from data for four particle-size fractions from four soil landscape publications. These methods were modified by taking into account possible autocorrelation between samples from the same site. The soil samples could not be classified with certainty as being derived from Wianamatta Group Shale or Hawkesbury Sandstone parent material. The classification of alluvial/fluvial-derived soils was no better than chance alone. A good classifier using four-fraction compositional data could not be built to determine geological parent material. Hence, the three size fractions of the Marshall soil texture diagram are insufficient to determine the geological parent material of a soil sample.

scholarly journals Effect of Mineralogy on the Beneficiation of REE from Heavy Mineral Sands: The Case of Nea Peramos, Kavala, Northern Greece

Minerals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 387 ◽  
Author(s):  
Christina Stouraiti ◽  
Vassiliki Angelatou ◽  
Sofia Petushok ◽  
Konstantinos Soukis ◽  
Demetrios Eliopoulos
Keyword(s):  
Particle Size ◽  
Magnetic Separation ◽  
Size Fraction ◽  
Heavy Mineral ◽  
Magnetic Fraction ◽  
High Concentration ◽  
Northern Greece ◽  
Size Fractions ◽  
Particle Size Fractions ◽  
Icp Ms

Beneficiation of a rare earth element (REE) ore from heavy mineral (HM) sands by particle size classification in conjunction with high-intensity magnetic separation (HIMS) was investigated. The HM sands of Nea Peramos, Kavala, Northern Greece, contain high concentrations of REE accommodated mainly in silicate minerals, such as allanite. However, the potential of the Northern Greek placer for REE exploitation has not been fully evaluated due to limited on-shore and off-shore exploration drilling data. Characterization of the magnetic separation fractions using XRD and bulk ICP-MS chemical analysis showed that the magnetic products at high intensities were strongly enriched in the light REE (LREE), relative to the non-magnetic fraction. Allanite and titanite are the major host mineral for REE in the magnetic products but mainly allanite controls the REE budget due its high concentration in LREE. SEM/EDS and ICP-MS analysis of the different particle size fractions showed LREE enrichment in the fractions −0.425 + 0.212 mm, and a maximum enrichment in the −0.425 + 0.300 mm. The maximum enrichment is achieved after magnetic separation of the particle size fractions. Mass balance calculations showed that the maximum REE recovery is achieved after magnetic separation of each particle size fraction separately, i.e., 92 wt.% La, 91 wt.% Ce, and 87 wt.% Nd. This new information can contribute to the optimization of beneficiation process to be applied for REE recovery from HM black sands.

Long-term fertilization effects on carbon and nitrogen in particle-size fractions of a Chinese Mollisol

2012 ◽  
Vol 92 (3) ◽  
pp. 509-519 ◽  
Author(s):  
Y. Yan ◽  
H. He ◽  
X. Zhang ◽  
Y. Chen ◽  
H. Xie ◽  
...  
Keyword(s):  
Particle Size ◽  
Size Fraction ◽  
Coarse Sand ◽  
Pig Manure ◽  
Size Fractions ◽  
Particle Size Fractions ◽  
Carbon And Nitrogen ◽  
Synthetic Fertilizers ◽  
Fertilization Effects

Yan, Y., He, H., Zhang, X., Chen, Y., Xie, H., Bai, Z., Zhu, P., Ren, J. and Wang, L. 2012. Long-term fertilization effects on carbon and nitrogen in particle-size fractions of a Chinese Mollisol. Can. J. Soil Sci. 92: 509–519. The response of soil organic matter (SOM) dynamics to long-term fertilization may be deduced from changes in the accumulation and distribution of different soil organic carbon (SOC) and nitrogen (N) pools. The SOC and N in particle-size fractions were therefore measured to assess the influences of pig manure and synthetic fertilizer application on the characteristics of these pools. A long-term fertilization experiment, established in 1979 in the Mollisol area (Gongzhuling, China) was used for this study. Composite soil samples (0–20cm) were collected in 2005 from 12 treatment plots that had received annual applications of pig manure, synthetic fertilizers or combinations of both. Soils were fractionated into fine clay (<0.2 µm), coarse clay (0.2–2 µm), silt (2–50 µm), fine sand (50–250 µm) and coarse sand (250–2000 µm) and then SOC and N contents in each particle-size fraction were measured. Although most of the SOC and N were associated with clay and silt fractions, the large proportion of silt in the soil mass played a key role in the retention of SOC and N. The application of pig manure alone increased accumulation of SOC and N in each particle-size fraction, but preferential enrichment was found in the coarse sand fraction. This indicates that pig manure is efficient in restoring SOM in the temperate Chinese Mollisol under a tilled maize (Zea mays L.) monocropping system and having a long frozen period in winter. The application of synthetic fertilizers had no clear effect on SOC and N accumulation or their distribution in particle-size fractions. However, the combined application of pig manure and synthetic fertilizers enhanced the accumulation of SOC and N in all particle-size fractions, and led to a shift of SOC and N from fine to coarse particles. We extended the hierarchy model for SOC protection to consider a shift in SOC accumulation from fine to coarse particles, depending on the initial SOC content of the specific soil. The findings reveal a clear positive interaction between pig manure and synthetic fertilizers that may improve the quantity of SOM in the temperate Chinese Mollisol.

Mineralization of active soil organic carbon in particle size fractions of a Brookston clay soil under no-tillage and mouldboard plough tillage

2010 ◽  
Vol 90 (4) ◽  
pp. 551-557 ◽  
Author(s):  
Z.D. Zhang ◽  
X.M. Yang ◽  
C.F. Drury ◽  
W.D. Reynolds ◽  
L.P. Zhao
Keyword(s):  
Particle Size ◽  
Clay Soil ◽  
Size Fraction ◽  
Mineralization Rate ◽  
Size Fractions ◽  
Particle Size Fractions ◽  
No Till ◽  
Mouldboard Plough ◽  
Soc Mineralization

Soil organic matter is a heterogeneous mixture of organic substances with different compositions and stabilities. To enhance soil organic carbon (SOC) sequestration, it is helpful to understand the distribution of SOC among the soil particle size fractions, the stabilities of the SOC within each fraction, and the influence of management practices, such as tillage, on SOC mineralization. Hence, the objectives of this study were to determine the distribution and mineralization rate of active SOC in the sand (53-2000 µm), silt (2-53 µm) and clay (<2 µm) size fractions of a Brookston clay soil under a corn-soybean rotation and three tillage scenarios. The tillages included long-term (24 yr) mouldboard plough (MP83), long-term (24 yr) no-till (NT83) and short-term (10 yr) no-till (NT97). Bulk soil from the top 10 cm was dispersed into sand, silt and clay size fractions by applying ultrasound energy (750 J mL-1) to a 1:4 soil:water suspension. The sand, silt and clay fractions of the three tillages were aerobically incubated at 20°C and 30% moisture (wt/wt), and the CO2-C emissions were measured over 103 d. The SOC contents followed the order clay > silt > sand for all three tillages. On a whole-soil basis and averaged over the tillage treatments, 55.8% of the SOC was in the clay size fraction, 37.2% was in the silt fraction and 7.0% was in the sand fraction. Carbon mineralization rate in the incubated samples decreased over time, and was related to both particle size fraction and tillage practice. There was very good agreement between a first-order decay model (Ct= C1 + C0 (1-e-kt)) and measured SOC mineralization rates for all size fractions and tillages. The C mineralization data indicated that: (1) the SOC in the clay and sand fractions was more decomposable than the SOC in the silt fraction; and (2) the SOC associated with the clay and silt fractions was more readily decomposable under no-till than under mouldboard plough.

scholarly journals Phosphorus and carbon in soil particle size fractions – A global synthesis

2018 ◽  
Author(s):  
Marie Spohn
Keyword(s):  
Particle Size ◽  
Organic Phosphorus ◽  
Meta Analysis ◽  
Size Fraction ◽  
Mean Annual Temperature ◽  
Strongly Correlated ◽  
Inorganic P ◽  
Size Fractions ◽  
Particle Size Fractions ◽  
Soil Particle Size Fractions

Abstract. Despite the importance of phosphorus (P) as a macronutrient, the factors controlling storage of organic phosphorus (OP) in soils are not yet well understood. The objective of this meta-analysis was therefore to investigate the distribution of OP, organic carbon (OC), and inorganic P (IP) in particle size fractions depending on climate, latitude and land use, based on data from published studies. The clay size fraction contained on average 8.8 times more OP than the sand size fraction and 3.9 and 3.2 times more IP and OC, respectively. The OP concentrations of the silt size and clay size fractions were both most strongly correlated with mean annual temperature (MAT) (R2 = 0.30 and 0.31, respectively, p 

scholarly journals Container Substrate-pH Response to Differing Limestone Type and Particle Size

HortScience ◽  
2007 ◽  
Vol 42 (5) ◽  
pp. 1268-1273 ◽  
Author(s):  
Jinsheng Huang ◽  
Paul R. Fisher ◽  
William R. Argo
Keyword(s):  
Particle Size ◽  
Size Fraction ◽  
Close Correlation ◽  
Hydrated Lime ◽  
Size Fractions ◽  
Particle Size Fractions ◽  
Ph Response ◽  
Reactivity Indices ◽  
Lime Particle ◽  
Substrate Ph

The objective of this study was to develop reactivity indices to describe the pH response for liming materials incorporated into container substrates. Three reactivity indices [particle size efficiency (PSE), fineness factor (FF), and effective calcium carbonate equivalence (ECC)] were developed based on lime particle size distribution and lime neutralizing value (NV) in CaCO3 equivalent. Six lime particle size fractions (2000 to 850, 850 to 250, 250 to 150, 150 to 75, 75 to 45, and <45 μm) separated from each of three calcitic limes and seven dolomitic limes were used to calibrate PSE, and were based on the increase in substrate pH (ΔpH) incited by the particle size fraction relative to reagent grade CaCO3 when mixed in a sphagnum peat substrate at 5 g CaCO3 equivalents per liter of peat. PSE for calcitic carbonate limes at day 7 (short-term pH response) were 0.13, 0.40, 0.78, 0.97, 1.00, and 1.00 for 2000 to 850, 850 to 250, 250 to 150, 150 to 75, 75 to 45, and <45 μm particle fractions, respectively. Other PSE values were described for dolomitic carbonate limestones and for long-term pH response, and PSE was modeled with a function over time. FF was calculated for a liming material by summing the percentages by weight in each of the six size fractions multiplied by the appropriate PSE. ECC rating of a limestone was the product of its NV and FF. ECC multiplied by the applied lime incorporation rate could be used to predict substrate-pH response. Estimated PSE values were validated in two experiments that compared expected and observed substrate pH using 29 unscreened carbonate and hydrated lime sources blended with peat. Validation trials resulted in a close correlation and no bias between expected and observed pH values. Revised PSE values are useful to evaluate the reactivity of different limestone sources for container substrates given the fine particle size, short crop duration, and pH sensitivity of many container-grown crops.

The reaction rate and residual value of particle size fractions of limestone in southern New South Wales

2020 ◽  
Vol 71 (4) ◽  
pp. 368 ◽  
Author(s):  
M. K. Conyers ◽  
B. J. Scott ◽  
M. G. Whitten
Keyword(s):  
Particle Size ◽  
Grain Yield ◽  
Soil Ph ◽  
Soil Acidity ◽  
Size Fraction ◽  
Residual Value ◽  
Efficient Technology ◽  
Size Fractions ◽  
Particle Size Fractions ◽  
Growing Seasons

Grain yield is frequently constrained by soil acidity in southern Australia yet limestone crushing plants are few and distant, making the use of limestone costly. The efficient technology of agricultural liming is therefore critical to the continuation of the practice following its adoption during the 1980s. We hypothesise that finer particles are the most effective materials for ameliorating soil acidity even over the longer term, when the residual value of coarser particles might be expected to be greater. Finer particle sizes of limestone, particularly &lt;0.075 mm, initially gave the largest increases in soil pH per tonne of limestone applied. Despite the rapid and large increase in soil pH with finer particles, there was no less residual value in surface soil pH after 7 years or in grain yield in the 7th and 8th growing seasons compared with coarser particles. Most particle size fractions of limestone converged to a similar soil pHca at 0–10 cm depth after about 6 years but the coarsest particle size fraction (2–5 mm) lagged the other five. Finer particles also resulted in better movement of alkali and Ca into the subsurface soil layers below the depth of incorporation (0–10 cm). The measurement of unreacted limestone in the soil showed that the dissolution of limestone took up to 3 years (1807 mm of rainfall) for the 2.5 t/ha rate and up to 6 years (3592 mm) for the 5 t/ha rate. The rapid increase in soil pH in Year 1, the slow ongoing reaction of limestone over 3–6 years as measured by unreacted limestone, the slow but measurable improvement in subsurface acidity, and the sustained residual value to grain yield over in excess of eight seasons, indicate that the use of finer liming materials should remain a viable practice for growers.

scholarly journals   Sulfur fractions in particle-size separates as influenced by long-term application of mineral and organic fertilizers

2012 ◽  
Vol 58 (No. 5) ◽  
pp. 242-248 ◽  
Author(s):  
H.W. Scherer ◽  
G. Welp ◽  
S. Förster
Keyword(s):  
Particle Size ◽  
Farmyard Manure ◽  
Size Fraction ◽  
Water Soluble ◽  
Organic Fertilizers ◽  
Particle Size Fraction ◽  
Size Fractions ◽  
Organic S ◽  
Particle Size Fractions

A field experiment established in 1962 was chosen to investigate the effect of long-term application of farmyard manure (FYM), compost (COM) and sewage sludge (SS), respectively, in two increments as compared to mineral fertilizer on inorganic and organic S fractions in particle-size separates (&lt; 0.002 mm, 0.002&ndash;0.02 mm, 0.02&ndash;2 mm). Independent of the particle-size the application of the high amounts of COM and SS resulted in the highest total S contents. It is evident that the particle-size fractions &lt; 0.002 mm contained the majority of total soil sulfur (S). The content of plant available S (water-soluble and adsorbed SO<sub>4</sub><sup>2&ndash;</sup>) decreased with increasing particle-size, while the influence of the kind and amount of organic fertilizers was negligible. As compared to C-bonded S sulfate esters were the dominant organic S fraction in size separates. The content of both organic S fractions was highest in the particle-size fraction &lt; 0.002 mm and lowest in the particle-size fraction 0.02&ndash;2 mm. The influence of the application of organic fertilizers was less pronounced. Only high application rates of COM and SS, respectively, resulted in the highest contents of both organic S fractions in the particle-size fractions 0.002&ndash;0.02 mm and 0.02&ndash;2 mm. &nbsp; &nbsp;

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