Mineral sources of potassium to plants for seven soils from south-western Australia

Soil Research ◽  
2002 ◽  
Vol 40 (8) ◽  
pp. 1357 ◽  
Author(s):  
Y. Pal ◽  
R. J. Gilkes ◽  
M. T. F. Wong

This investigation was conducted with surface horizon samples from 7 south-western Australian soils and their 3 size fractions (sand, silt, and clay). The K release of these materials was measured for several extractants; the highest amounts of K were released from the clay (<2 μm) fraction. The presence of sand-size feldspars and incomplete removal of attached organic matter resulted in sand releasing significant amounts of K. The proportions of total K released in boiling 1 m HNO3 by the sand, silt, and clay fractions ranged from 0.4 to 3.4%, 2.6 to 36.3%, and 11.2 to 51.4%, respectively, and from 2.0% to 22.9% for the whole soils. Cumulative K uptake by 6 harvests of ryegrass over 260 days ranged from 0.26 to 1.23 cmol/kg soil.The clay fraction released higher proportions of total K to acid compared with the sand and silt size fractions because of the high specific surface area of the clay and because it contained proportionately higher amounts of illite, which releases K by both ion exchange and dissolution, whereas K release from feldspars requires congruent dissolution of the silicate structure. The differences in contents of StepK (relatively available fraction of the non-exchangeable K) and CRK (constant rate K) for 1 m HNO3 dissolution of these soils and size fractions reflect differences in mineralogical composition between the soils and size fractions. The low contents of StepK for the sand fraction indicated that K was strongly retained by feldspars. The soils with high CRK values had significant amounts of illite in the clay fraction. Values of CRK were positively related to cumulative K uptake and cumulative dry matter yield of ryegrass.

Soil Research ◽  
2001 ◽  
Vol 39 (4) ◽  
pp. 813 ◽  
Author(s):  
Y. Pal ◽  
R. J. Gilkes ◽  
M. T. F. Wong

Seven surface horizon soils and their sand, silt, and clay fractions were characterised for mineralogy, and K release by extracting samples with 1 mM CaCl 2 solution daily for 10 days. The low silt content is characteristic of many Western Australian soils, which may provide a partial explanation of the paucity of available K in soils that contain little silt-size primary minerals. The sand and silt fractions were dominated by quartz and contained significant amounts of K-feldspars. The clay fraction was dominated by kaolinite, and some samples contained illite/mica, inhibited vermiculite, and gibbsite. On a per unit weight basis the clay-fraction released the largest amount of K followed in sequence by the silt and sand. The contribution of size fractions to total K release by the soil ranged from 50 to 87%, 2 to 7%, and 10 to 44% for the clay, silt, and sand, respectively. Linear plots of K release versus time 1/2 for the soils, and the sand and silt fractions, indicated that a parabolic diffusion equation adequately describes the K release process. For some clay samples this diffusion controlled kinetic is not strictly obeyed during the initial period of K desorption due to rapid exchange of adsorbed K at sites on external surfaces. The Elovich equation plots show a discontinuity in slope and support the hypothesis of the multireactive nature of K exchange sites for these soils. The parabolic diffusion rate constant closely predicted K supply to plants as it has a close positive relationship (r = 0.99) with total K uptake by ryegrass for 260 days of growth.


1984 ◽  
Vol 64 (1) ◽  
pp. 99-106 ◽  
Author(s):  
T. AL-KANANI ◽  
A. F. MacKENZIE ◽  
G. J. ROSS

The K release characteristics of surface samples from five Quebec soils were investigated. Each soil was fractionated by size into six separates. Each separate was extracted with 1 M ammonium acetate (NH4OAc), with 1 M nitric acid (HNO3) and with sodium tetraphenylboron (NaTPB) and the K extracted was determined. The clay separates contained most of the HNO3 and NaTPB-extractable K. The average amounts of K removed by 1 M HNO3 and NaTPB from the clay was up to 16 times more than that released from silt or sand fractions. The strong relationship between extractable K and clay content was probably due to the similarity in mineralogical composition and degree of weathering of these soils. Clay-sized chlorite and vermiculite were destroyed by the HNO3 extraction but not by the NaTPB extraction. Crop response to K fertilizer was generally reduced as clay content and extractable K increased. Key words: Extractable K, NaTPB-K, HNO3-K


Author(s):  
Igor Papish ◽  
Oleksii Telehuz

The article presents data on gross chemical and mineralogical composition of clay faction found in typical chernozems occurred within the Podillia Upland. Geographical regularities of formation as regards clayey profile of Chernozems pertaining to the same genetic series are revealed. The relationship between conditions and Chernozem development stage, character of vertical differentiation of basic mineral phases of clayey plasma and its chemical and mineralogical composition are shown. Izoclayey profile of hydromicas is the consequence of their relative accumulation as a result eluviation of colloid-dispersible mica-smectite minerals. The character of clay profile observed in Chernozems is determined by the correlation of intensity of carbonates leaching, lessivage and soils argillisation. Typical Podolian Chernozems are characterised with the like weathering crust of silicate type. The modern Chernozem clayey profile originated mainly during a wetter stage of soil formation. In the ploughable layer a high content of clastic minerals (quartz, potassium feldspar, sodium plagioclase) is observed. Random mixed and stratified mica-smectite minerals with a high content (>50 %) of smectite packets (33–63 %), hydromica (33–52 %), and kaolinite plus chlorite (4–15 %) are present in the profile. The mineralogical composition of soils clay fraction indicates obvious signs of smectite eluviation and relative illite accumulation. Clayey profile of the Bug upstream plateau located within the Podillia Upland is atypical for Chernozems found in the eastern forest-steppe and steppe areas. The distribution character of layered silicates, especially smectite, is even more contrastive. Clayey plasma redistributes differentially through leaching and lessivage processes. Accumulative type of sludge deposits formed in Chernozems of the Dniester plateau located within the Podillia Upland, even profile distribution of basic oxides and molar ratios of SiO2 : Al2O3 and SiO2 : Fe2O3 against the background of decreased downward smectite content indicate weakened eluviation of fine-grained clays towards the Dniester. The prevalence of smectite over hydromicas within the entire profile indicates argillisation of Chernozems. Key words: Chernozem, chemical-mineralogical composition, clayey minerals, hydromica, smectite, kaolinite, leaching, lessivage, argillisation.


2014 ◽  
Vol 31 (2) ◽  
pp. 133-141 ◽  
Author(s):  
Fabian Welc ◽  
Radosław Mieszkowski ◽  
Sebastian Kowalczyk ◽  
Jerzy Trzciński

Abstract This paper presents the preliminary results of ground penetrating radar sounding applied at the desert archaeological site in Saqqara (Egypt). The survey was carried out in 2012 within a project realized by Institute of Archaeology, Cardinal Stefan Wyszyński University in Warsaw and the Faculty of Geology, University of Warsaw. One of the key aims of the research was testing the application of ground penetrating radar to non-invasive surveys of desert archaeological sites. Radargrams obtained for area of so called the Dry Moat channel surrounding the Step Pyramid complex have shown the geological structure of its filling. It comprises among others debris-sand conglomerate of diluval origin characterized by a significant content of the clay fraction and clay minerals. Such lithological content strongly attenuate the propagation of EM waves, restricting the depth range of the GPR survey. The conducted geophysical prospection west to the Step Pyramid in Saqqara has confirmed the high applicability of the GPR method in non-invasive studies of vast architectural structures, such as the monumental ditch surrounding the Step Pyramid known as the Dry Moat. It should summarised that high horizontal resolution obtained during GPR survey is a result of local geological structure of the searched area, i.e. strong lithological contrast of the sediments filling the Dry Moat, which, depending on their mineralogical composition


Clay Minerals ◽  
1979 ◽  
Vol 14 (3) ◽  
pp. 229-240 ◽  
Author(s):  
Elen Roaldset

AbstractThe distribution of rare earth elements (REE) in two different sediments, a marine clay and a till, was found to be dependent both on grain size and mineralogical composition. In the marine clay the REE content was highest in the coarsest fraction; in the till REE were markedly enriched in the finest fraction. Detrital and authigenic origins for different size fractions have been attributed on the basis of REE contents.


2019 ◽  
Vol 110 ◽  
pp. 01055
Author(s):  
Liliya Kazanskaya ◽  
Nicolay Privalov ◽  
Svetlana Privalova

Nowadays, it is acknowledged that the use of mineral additives based on ground slag is one of ways of resource saving and improvement of technical properties of cement composites. Mineral additives with fineness similar to the Portland cement fineness are often used to replace part of Portland cement. Two kinds of ultra-fine ground granulated blast furnace slag that differ in composition and fineness were studied in the paper. Water-reduction due to effect of super plasticizer in slag-Portland cement compositions with amount of slag up to 70% was studied. The results of reduction of binder quantity per 1 kg of chemical admixture due to significant water-reduction are obtained and analysed. Correlations depending on kind, amount and fineness of slags, as well as depending on mineralogical composition of Portland cement were stated. The ultra-fine mineral additives based on ground slag with high specific surface area can be used for significant reduction of compositional binder.


Revista CERES ◽  
2012 ◽  
Vol 59 (6) ◽  
pp. 867-872 ◽  
Author(s):  
Julião Soares de Souza Lima ◽  
Rone Batista de Oliveira ◽  
Samuel de Assis Silva

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.


Soil Research ◽  
1993 ◽  
Vol 31 (1) ◽  
pp. 51 ◽  
Author(s):  
DC Golden ◽  
JB Dixon ◽  
Y Kanehiro

The mineralogical composition of the surface soil horizon (0-15 cm) of Wahiawa soil (Tropeptic Eutrustox) was investigated by X-ray diffraction (XRD), high gradient magnetic separation (HGMS), transmission electron microscopy (TEM), and infrared methods. The concentration of lithiophorite decreased with particle size and none was present in the clay fraction as indicated by XRD. Lithiophorite was further concentrated from the crushed sand-sized fraction by HGMS. Hexagonal, electron-dense, often twinned lithiophorite particles were identified by electron diffraction. Differential infrared (DIR) spectra obtained by dissolving Mn oxides in acidified hydroxylamine hydrochloride (HAHC) indicated lithiophorite as the HAHC-soluble Mn-phase. Lithiophorite compositiion, as revealed by chemical analysis of the HAHC extracts, consisted of appreciable amounts of Mn, Al, Zn, Co and Mg, and less than stoichiometric amounts of Li. Sodium hydroxide treatment apparently altered the lithiophorite, as revealed by the DIR spectrum of the hydroxylamine-soluble fraction of the NaOH-treated sample compared with the untreated sample. The high crystallinity of the lithiophorite was suggested by its resistance to chemical dissolution and narrow X-ray diffraction lines. No evidence for the presence of todorokite or birnessite was found, contrary to earlier reports. Examination of sand-sized nodules by scanning electron microscopy indicated large (2-5 �m) platy lithiophorite crystals at the surface of these nodules. Electron microprobe analysis of these platy particles indicated iron enrichment near the surface. The freshly fractured nodule surface revealed numerous unaltered platy crystals of lithiophorite filling the veins of the nodule.


1990 ◽  
Vol 258 (1) ◽  
pp. G45-G51
Author(s):  
L. Sestoft ◽  
M. Folke

The effects of low flow and reestablished normal flow on K+ balance and carboxylic acid balance was studied in perfused liver of 48-h starved rats at perfusate pH 7.4 and 6.8. The rate of net K+ release induced by ouabain was 1.8 mumol.min-1.g-1 at pH 7.4 and 1.4 mumol.min-1.g-1 at pH 6.8. Lowering of flow to 30% normal was accompanied by a transient, diphasic loss of K+ (max 0.15 mumol.min-1.g-1). Reestablished normal flow was immediately accompanied by a monophasic K+ uptake (max 0.35 mumol.min-1.g-1). These changes in potassium balance were independent of perfusate pH. Reduction of flow caused an almost immediate depolarization of 4 mV followed by a steady tendency to repolarization. Reestablished normal flow induced a transient hyperpolarization. Production of carboxylic acids during the low flow period did not correlate with the diphasic time course of K+ loss, and carboxylic acid uptake after reestablishment of flow did not correlate with the transient uptake of K+. The data show that the initial phase of K+ loss during low flow is due to inhibition of the Na(+)-K(+)-pump; the second phase may be reasonably explained by increased K+ permeability concomitant to cellular volume regulation.


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