THE CONTROLLING FACTORS OF SILICON SOLUBILITY IN SOIL SOLUTION

Silica is a beneficial element for rice plants which can protect from blast disease, increase stem strength, and alleviate abiotic stress. Silicon in soil solution is affected by several factors such as pH, temperature, organic matter, and redox potential (Eh). This study aims to investigate the controlling factor of Si solubility in soil solution. In the present study, Japanese silica gel (JSG) and Ultisols were collected from Japan. In laboratory experiment, the effects of Ca (calcium), Mg (magnesium) and others on solubility of Si (silica) were investigated. Under submerged condition, ten gram of soil with silica gel, Ca and Mg in plastic tube were incubated at 300C for 29 days. Calcium and Mg were applied into soil, at the concentration of 5, 10, 15 mg Ca L-1(T2, T3, T4 respectively) and 5, 10, 15 mg Mg L-1(T5, T6, T7 respectively). There was two controls as a follow T0 (soil) and T1 (soil + silica gel). During incubation, Si, Ca, Mg, Fe, and Mn concentrations in surface water were measured using ICP spectroscopy at day 8, 15, and 29. The results show the soil before treatment was slightly acidic (pH 5.7) and extractable Si concentration was 267.1 mg SiO2 kg-1. It was classified to be below critical level of available Si for rice (300 mg SiO2 kg-1). Total concentration of Ca and Mg in soil solution were highest for treatment T4 and T7, respectively compared with other treatments. On the first 8 days of incubation, Si released into soil solution was higher in T1 and T2 compared to other treatments. The solubility of Si was significantly positive correlated with Mn, Eh, and negatively correlated with pH, that indicated these were the controlling factors of the Si release in soil solution. There was no correlation between Si and Ca or Mg concentration in soil solution.

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Controlling factors in electron and energy transfer reactions on silica gel surfaces

Photochemical & Photobiological Sciences ◽

10.1039/b207835j ◽

2002 ◽

Vol 1 (11) ◽

pp. 896-901 ◽

Cited By ~ 8

Author(s):

David R. Worrall ◽

Iain Kirkpatrick ◽

Sian L. Williams

Keyword(s):

Energy Transfer ◽

Silica Gel ◽

Controlling Factors ◽

Transfer Reactions

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How Salinity Damages Citrus: Osmotic Effects and Specific Ion Toxicities

HortTechnology ◽

10.21273/horttech.15.1.0095 ◽

2005 ◽

Vol 15 (1) ◽

pp. 95-99 ◽

Cited By ~ 34

Author(s):

Louise Ferguson ◽

Steven R. Grattan

Keyword(s):

Soil Solution ◽

Woody Plants ◽

Total Concentration ◽

Citrus Fruit ◽

Nutrient Status ◽

Threshold Concentration ◽

Ion Toxicity ◽

Direct Injury ◽

Specific Ion Effect ◽

Osmotic Effects

There are two ways salinity can damage citrus: direct injury due to specific ions, and osmotic effects. Specific ion toxicities are due to accumulation of sodium, chloride, and/or boron in the tissue to damaging levels. The damage is visible as foliar chlorosis and necrosis and, if severe enough, will affect orchard productivity. These ion accumulations occur in two ways. The first, more controllable and less frequent method, is direct foliar uptake. Avoiding irrigation methods that wet the foliage can easily eliminate this form of specific ion damage. The second way specific ion toxicity can occur is via root uptake. Certain varieties or rootstocks are better able to exclude the uptake and translocation of these potentially damaging ions to the shoot and are more tolerant of salinity. The effect of specific ions, singly and in combination, on plant nutrient status can also be considered a specific ion effect. The second way salinity damages citrus is osmotic effects. Osmotic effects are caused not by specific ions but by the total concentration of salt in the soil solution produced by the combination of soil salinity, irrigation water quality, and fertilization. Most plants have a threshold concentration value above which yields decline. The arid climates that produce high quality fresh citrus fruit are also the climates that exacerbate the salt concentration in soil solution that produces the osmotic effects. Osmotic effects can be slow, subtle, and often indistinguishable from water stress. With the exception of periodic leaching, it is difficult to control osmotic effects and the cumulative effects on woody plants are not easily mitigated. This review summarizes recent research for both forms of salinity damage: specific ion toxicity and osmotic effects.

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Speciation of Cu and Zn in soil solution in a long-term fertilization experiment

Soil Science Annual ◽

10.2478/ssa-2014-0004 ◽

2014 ◽

Vol 65 (1) ◽

pp. 25-28

Author(s):

Beata Rutkowska ◽

Wiesław Szulc

Keyword(s):

Soil Solution ◽

Total Concentration ◽

Speciation Analysis ◽

Mineral Fertilization ◽

Fertilization Experiment ◽

Limited Mobility ◽

Main Form ◽

Zn Concentration ◽

Cu And Zn

Abstract The changes of the concentration of Cu and Zn in the soil solution and the percentage of particular forms of these elements in the soil solution were investigated in the long-term fertilization experiment. The soil solution was obtained following the vacuum displacement method. Speciation of copper and zinc ions was determined with MINTEQA2 for Windows software. The results of the investigation indicated that exclusive mineral fertilization (NPK) caused an increase of Cu and Zn concentration in the soil solution. Organic fertilization (FYM) resulted in a decrease of Cu and an increase of Zn concentration in the soil solution. Liming limited mobility of both analysed elements. The results of speciation analysis showed that regardless of the fertilization mode, the organo-mineral complexes are the main form of Cu occurring in soil solution. The percentage of Cu-DOC complexes ranges from 76.5 to 85.2% of the total concentration of Cu in the soil solution. The particular forms of copper can be sorted depending on the percentage in the soil solution as follows: Cu-DOC>Cu2+>Cu-CO3. The main form of Zn in the soil solution are active Zn2+ ions. The share of Zn2+ in total zinc concentration in the soil solution ranged from 76.9% to 86.4%. Forms of zinc in the soil solution can be arranged with regard to their percentage as follows: Zn2+>Zn-DOC>ZnCl+>ZnHCO3+.

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Concentrations of rare earth elements in some Australian soils

Soil Research ◽

10.1071/sr9960735 ◽

1996 ◽

Vol 34 (5) ◽

pp. 735 ◽

Cited By ~ 38

Author(s):

E Diatloff ◽

CJ Asher ◽

FW Smith

Keyword(s):

Rare Earth ◽

Rare Earth Elements ◽

Soil Solution ◽

New South ◽

Total Concentration ◽

Acid Soils ◽

Solution Ph ◽

South Wales ◽

Low Concentrations ◽

Soil Solutions

Total, exchangeable, and soil solution concentrations were measured for 15 rare earth elements (REEs) in 9 soils from Queensland and New South Wales. In a further 10 acid soils, effects of amendment with CaCO3 or CaSO4 . 2H2O were measured on the concentrations of REEs in soil solution. The total concentration of the REEs in soil solutions from unamended soils ranged from below the detection limit (0.007 µM) to 0.64 µM. Lanthanum (La) and cerium (Ce) were the REEs present in the greatest concentrations, the highest concentrations measured in the diverse suite of soils being 0.13 µM La and 0.51 µM Ce. Rare earth elements with higher atomic numbers were present in very low concentrations. Exchangeable REEs accounted for 0.07 to 12.6% of the total REEs measured in the soils. Addition of CaCO3 increased soil solution pH and decreased REE concentrations in soil solution, whilst CaSO4 . 2H2O decreased soil solution pH and increased the concentrations of REEs in soil solution. Solubility calculations suggest that CePO4 may be the phase controlling the concentration of Ce in soil solution.

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Effect of the Long-Term Application of Sewage Sludge to A Calcareous Soil on Its Total and Bioavailable Content in Trace Elements, and Their Transfer to the Crop

Minerals ◽

10.3390/min11040356 ◽

2021 ◽

Vol 11 (4) ◽

pp. 356

Author(s):

Armelle Zaragüeta ◽

Alberto Enrique ◽

Iñigo Virto ◽

Rodrigo Antón ◽

Henar Urmeneta ◽

...

Keyword(s):

Sewage Sludge ◽

Organic Amendment ◽

Agricultural Soils ◽

Total Concentration ◽

Organic Fertilizer ◽

Barley Straw ◽

Soil Protection ◽

Diethylene Triamine Pentaacetic Acid ◽

Mn Concentrations

Sewage sludge (SS) can be used as an organic amendment in agricultural soils, provided they comply with the relevant legislation. This use can incorporate traces of metals into the soil, which can cause environmental or human health problems. In the study period between 1992 and 2018 (26 years), it was observed that the use of SS as an organic fertilizer significantly increased the total concentration of Zn, Cu, Cr, Ni and Hg of this study between 55.6% (Hg) and 7.0% (Ni). The concentration of Zn, Cu, Pb, Ni and Cd extracted with DTPA, also increased between 122.2% (Zn) and 11.3% (Cd). In contrast, the Mn concentrations extracted with Diethylene Triamine Pentaacetic Acid (DTPA)were 6.5% higher in the treatments without SS. These changes in the soil had an impact on the crop, which showed a significant increase in the concentration of Zn, Cu and Cr in the grain, between 15.0% (Cr) and 4.4% (Cu), and a decrease in the concentration of Mn, Cr and Ni in the barley straw when SS was added to the soil between 32.2% (Mn) and 29.6% (Ni). However, the limits established by current legislation on soil protection and food were not exceeded. This limited transfer to the crop, is likely due to the high content of carbonates and organic matter in the soil, which limit the bioavailability of most of the trace metals (TM) in the soil. As a conclusion, we observe that the use of SS as an organic amendment increased the concentration of some TM in the soil, in its bioavailable forms, and in the crop.

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Effect of depth and lime or phosphorus-fertilizer applications on the soil solution chemistry of some New Zealand pastoral soils

Soil Research ◽

10.1071/sr9950461 ◽

1995 ◽

Vol 33 (3) ◽

pp. 461 ◽

Cited By ~ 14

Author(s):

DM Wheeler ◽

DC Edmeades

Keyword(s):

Soil Solution ◽

Soil Ph ◽

Maximum Yield ◽

Solution Chemistry ◽

Phosphorus Fertilizer ◽

Solution Ph ◽

Soil Solutions ◽

P Fertilizer ◽

P Rate ◽

Mn Concentrations

Thirteen trails were sampled to investigate the effects of depth, or the surface application of lime and phosphorus (P) fertilizer, on solution composition. Soil solutions were extracted by centrifuge from field moist soils within 24 h of sampling. Solution Ca, Mg, Na and K, Al, Mn and Fe concentrations generally decreased and Al, Mn and Fe concentrations generally increased with depth; although exceptions occurred. The largest decrease occurred in the first 25-50 mm of soil. Higher solution Al concentrations occurred in a band at a depth of between 50 and 100 mm in some soils. Lime generally increased solution pH and solution Ca, Mg and HCO3 concentrations, and reduced solution Al, Fe and Mn concentrations in the topsoils. In one soil (Matapiro silt loam) 2 years after lime was applied, lime increased solution pH down to a depth of 100 mm, Ca and HCO3 down to 75 mm and Mg down to 50 mm. Lime also decreased solution Al and Mn down to 75 mm and Fe down to 50 mm. In one series of trials, lime increased solution Ca concentrations at a depth of 50-100 mm 4 years after application in six out of the eight sites. In the same trial series, the application of P fertilizer increased solution P concentrations at 0-50 mm from a mean of 5 �M in the no-added P plots up to a mean of 56 �M at the highest P rate. The highest solution P concentration recorded was 194 �M. The increase in solution P concentrations for a given application of fertilizer P varied from 0.05 to 1.03 �M P per kg P ha-1 applied. Maximum pasture yield and 90% maximum yield occurred when solution P concentrations were about 28 and 14 �M respectively. Solution P concentrations determined from P adsorption isotherms were not a good indicator of solution P concentrations measured in soil. Solution pH was higher than soil pH (1:2.5 soil:water ratio, 2 h equilibration) with a solution pH of 6.0 corresponding to a soil pH in water of about 5.2.

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Soil Humus

The Chemistry of Soils ◽

10.1093/oso/9780190630881.003.0007 ◽

2016 ◽

Author(s):

Garrison Sposito

Keyword(s):

Acetic Acid ◽

Organic Acids ◽

Soil Solution ◽

Root Exudates ◽

Total Concentration ◽

Mineral Weathering ◽

Plant Roots ◽

Soil Microbiome ◽

Soil Humus ◽

Ethanoic Acid

Biomoleculesare compounds synthesized to sustain the life cycles of organisms. In soil humus, they are usually products of litter degradation, root excretion, and microbial metabolism, ranging in molecular structure from simple organic acids to complex biopolymers. Organic acids are among the best-characterized biomolecules. Table 3.1 lists five aliphatic (meaning the C atoms are arranged in open-chain structures) organic acids associated commonly with the soil microbiome. These acids contain the unit R—COOH, where COOH is the carboxyl groupand R represents either H or an organic moiety. The carboxyl group can lose its proton easily within the normal range of soil pH (see the third column of Table 3.1) and so is an example of a Brønsted acid. The released proton, in turn, can attack soil minerals to induce their decomposition (see Eq. 1.2), whereas the carboxylate anion (COO-) can form soluble complexes with metal cations, such as Al3+, that are released by mineral weathering [for example, in Eq. 1.7, rewrite oxalate, C2O42-, as (COO-) 2]. The total concentration of organic acids in the soil solution ranges up to 5 mM. These acids tend to have very short lifetimes because of biocycling, but they abide as a component of soil humus, especially its water-soluble fraction, because they are produced continually by microorganisms and plant roots. Formic acid (methanoic acid), the first entry in Table 3.1, is a monocarboxylic acid produced by bacteria and found in the root exudates of maize. Acetic acid (ethanoic acid) also is produced microbially—especially under anaerobic conditions—and is found in root exudates of grasses and herbs. Formic and acetic acid concentrations in the soil solution range from 2 to 5 mM. Oxalic acid (ethanedioic acid), which is ubiquitous in soils, and tartaric acid (D- 2,3-dihydroxybutanedioic acid) are dicarboxylic acids produced by fungi and excreted by plant roots; their soil solution concentrations range from 0.05 to 1 mM. The tricarboxylic citric acid (2-hydroxypropane- 1,2,3-tricarboxylic acid) is also produced by fungi and excreted by plant roots. Its soil solution concentration is less than 0.05 mM.

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Effect of sodicity and zinc on soil solution chemistry of manganese under submerged conditions

The Journal of Agricultural Science ◽

10.1017/s0021859600082800 ◽

1988 ◽

Vol 111 (1) ◽

pp. 51-55 ◽

Cited By ~ 2

Author(s):

U. S. Sadana ◽

P. N. Takkar

Keyword(s):

Soil Solution ◽

Sandy Loam ◽

Significant Negative Correlation ◽

Solution Chemistry ◽

Soil Solution Chemistry ◽

Solution Ph ◽

Sodic Soils ◽

Mn Concentration ◽

Submerged Conditions ◽

Mn Concentrations

SummaryIn a greenhouse experiment, the effect of soil sodicity (exchangeable Na percentage 3, 10, 20, 40 and 60) and Zn (0 and 10 mg Zn/kg soil) on soil solution chemistry of Mn was investigated under submerged conditions. Calculated amounts of NaHCO3 were added to Typic Ustifluvent sandy loam soil to obtain required sodicity levels. The soil solutions collected under the atmosphere of N2 gas by gravity were analysed for pH, pE, EC and Mn. Soil submergence decreased pH and pE, and increased Mn concentrations in all the treatments. Maximum Mn concentration was obtained at 14-day submergence. Increasing sodicity levels increased soil solution pH and decreased Mn concentrations. A significant negative correlation (r = -0·74**) was observed between soil solution Mn and pH. Despite large variations in pH, pE, ionic strength and Mn concentration in soil solution, the values of expressions: pH+½log Mn2+ + ½log Pco2 and pMn+2pOH were fairly constant and close to the theoretical values of 4·4 and 17·2 respectively, indicating that the MnCO3-Mn2+ system regulated the solubility of Mn2+ in the sodic soils. Addition of ZnSO4 did not have appreciable effects on the soil solution pH, Mn and solid phases of Mn.

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