Research Article Physicochemical Properties and Surface...

Hindawi Publishing CorporationApplied and Environmental Soil ScienceVolume 2013 Article ID 252861 11 pageshttpdxdoiorg1011552013252861

Research ArticlePhysicochemical Properties and Surface Charge Characteristicsof Arid Soils in Southeastern Iran

A H Moghimi1 J Hamdan1 J Shamshuddin1 A W Samsuri1 and A Abtahi2

1 Department of Land Management Faculty of Agriculture Universiti Putra Malaysia 43400 Serdang Selangor Malaysia2 Department of Soil Science Faculty of Agriculture Shiraz University Shiraz 7915847669 Iran

Correspondence should be addressed to A H Moghimi moghimiabolhasangmailcom

Received 2 March 2013 Revised 15 May 2013 Accepted 20 May 2013

Academic Editor Davey Jones

Copyright copy 2013 A H Moghimi et alThis is an open access article distributed under the Creative Commons Attribution Licensewhich permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited

The majority of previous studies on surface charge characteristics were done on tropical and subtropical soils Information of suchstudies in the arid regions is limited A study was conducted to investigate the relation between soil chemical and mineralogicalproperties and surface charge characteristics of an arid region in Southeastern Iran Eight soil pedons representing the alluvialand the colluvial deposits were described and their mineralogical and physicochemical properties were examined The commonclay minerals in the studied area are smectite palygorskite kaolinite chlorite and illite The point of zero charge (pH

0) values

are low (285ndash335) in all soils mostly affected by organic carbon (OC) and free iron oxide (Fed) pH0 has a significant negativecorrelation with pH under field conditions (119903 = minus045lowast 119875 lt 005) The point of zero net charge (PZNC) levels for all the soils werelt2 due to the excess negative charge in these soils The estimated PZNC values were less than pH

0in all soils because of the high

permanent negative charge in these soils The permanent negative charge (120590119901) of the soils studied is high and it has a significant

positive correlation with pH CEC Na Mg SAR clay content palygorskite OC and Fed

1 Introduction

Soil surface charges affect the chemical properties of soil byvarying the quantity of electric and surface charge densitySurface charge properties have an important bearing on themigration of ions in soil the formation of organomineralcomplexes soil structure plant nutrition and the dispersionflocculation swelling and shrinkage of the soil fractions [1]Based on differences in the surface properties soils can beclassified into two basic categories permanent-charge soilsand variable-charge soils [2 3]

Point of zero charge (PZC) often denoted as pH0is one

of the most important parameters used to describe variable-charge surfaces [4] Uehara and Gillman [5] indicated thatpH0is the pH where the amounts of negative and positive

charge of variable charge components where these are equalThe pH

0value for the temperate region of Iran was reported

in the range of about 26 to 375 [6] Anda et al [7] reportedthat the pH

0of three Oxisols in Malaysia was about 39 to

57The previous studies showed that the pH0values decrease

with increasing organic matter content and increase with

increase in sesquioxides [6ndash8] Taubaso et al [9] reported thatthe pH

0values of Argentinean provinces soils were smaller

than the pH in water indicating that these soils had negativecharge under natural conditions

Gonzales-Batista et al [10] reported that for systems freeof permanent charge the point of zero net charge (PZNC)should coincide with pH

0 but for systems where permanent

and variable charges coexist PZNC may differ from pH0

Usually in the young soils (Entisols or Inceptisols) PZNCis lower than its pH

0and higher than pH

0if the soils are

highly weathered such as Oxisols [9] In addition the modelof Uehara and Gillman [11] and Yu [2] predicts that in soilshaving permanent negative charge the PZNC value is lowerthan the pH

0and vice versa

Most studies on soil surface charge properties wereconducted in tropical and subtropical regions where the soilsare poor and low in negative charge In Iran Sharami et al [6]conducted similar study for temperate soils of the Northernregion but no studywas done on arid regions of Southern Iranor elsewhere in the world The electrochemical properties ofsoils are useful fundamental knowledge in solving the fertility

2 Applied and Environmental Soil Science

problems of soils of the arid regions For example in thearid regions the NH

4

+ fixed by soil particles and leachedout as NO

3

minus form due to high permanent negative charge inthe surface of soil particles [12] in comparison with highlyweathered soils whereNO

3

minus leaching because of high positivecharge present in the soils [13] The objectives of this studywere to determine the physicochemical and mineralogicalproperties the pH

0 PZNC and permanent negative charge

(120590119901) and to determine the relation between pH

0and 120590

119901with

characteristics of arid soils in Southeastern Iran

2 Materials and Methods

21 Description of the Study Area The studied area is locatedin the province of Hormozgan Southeastern Iran betweenlatitude 28∘81015840 and 28∘151015840 North and longitudes 56∘51015840 and 56∘151015840 East (Figure 1) The climate is arid with an average annualprecipitation of about 162mm and evaporation of 4243mmBurdon [14] reported that the estimated potential evapotran-spiration could be in excess of 50 times the mean annual pre-cipitation The temperature regime is hyperthermic with anaridic and usticmoisture regimes [15]The sedimentary rocksaccompanyingmarine deposits of the Tertiary age formed thecatchment area which is predominantly composed of thickalluvial and colluvial materials occasionally deposited by theDehshaykh River for the past thousands of years The riveris dry most of the time except during heavy downfall Thecatchment is currently cultivated with wheat maize potatoand watermelon as important agricultural crops [16]

Eight pedons were selected among the dug profilesrepresenting alluvial fan and colluvial deposits along theslope area of the catchment by geopedology approach anddifferent soil horizons were sampled for laboratory analysisThe morphological properties of the soils were described inthe field [17] and were classified according to the USDA SoilTaxonomy [18]

22 Methods

221 Physical and Chemical Analyses Field study and sam-ples collectionwere carried out in the summer season of 2009(August to September) The soil samples were air-dried andsieved with a 2mm sieve and kept in plastic bags prior toanalysis

The particle size analysis was carried out by the pipettemethod [19] Organic matter content of the soil was deter-mined by the wet combustion procedure of Walkley andBlack [20] and Fe

2O3was estimated by the dithionite-citrate-

bicarbonate method [21] The pH was measured in thesupernatant suspension of 1 1 soil water suspension pH [17]1 25 liquid 001M CaCl

2solution (pHCaCl

2

) [22] and 1 25soil H

2O (pHH

2O) and 1 25 soil 1MKCl solution (pHKCl)

[23]Thebulk density (120588119887) was estimated by coremethod [24]

and the electrical conductivity (EC) analysis wasmeasured inthe saturated extract [25] The calcium carbonate equivalent(lime) was measured by acid neutralization [26] exchange-able cations content and the cation exchange capacity (CEC)of the soils were determined by the 1M ammonium acetate

40∘

35∘

30∘

25∘

45∘

50∘

55∘

60∘

65∘

N

Paki

stan

Afg

hani

stan

Turkmenistan

Study area

Bandarabbas

Caspian Sea

Tehran

Iran

Shiraz

Persian

Turk

ey

Iraq

Kuwait

Saudi ArabiaGulf

Figure 1 Location of the study area

(pH 7) method The exchangeable cations (Ca2+ and Mg2+)in the leachate were determined by atomic absorption spec-trophotometer (AAS Perkin-Elmer 047-1705) whereas K+andNa+ weremeasured by flame spectrophotometerThe soilsolution data (Na+ Ca2+ Mg2+ given in cmolckg

minus1) was usedto calculate the sodium adsorption ratio (SAR) where SAR =Na+[(Ca2+ + Mg2+)2]minus05

222 Determination of Point of Zero Charge Point of zerocharge (PZC) denoted as pH

0 is defined as the pH at which

the net charge on the variable charge components is zeroand was determined according to the method of Gillman andSumner [27] Six portions of 2 g of 2mm air-dried sampleswere weighed into 50mL plastic centrifuge tubes and shakenwith 20mL of 01M CaCl

2for 2 h to saturate the soil with

Ca The suspension was centrifuged (3000 rpm 10min) andthe supernatant was discarded The Ca saturated soil waswashed twice with 20mL of 0002MCaCl

2and after the

third addition of 20mL of 0002CaCl2 the pH was adjusted

to six values of 01MHCl in the range of 35 to 6mL bydropwise addition Equilibration of the pH took several daysWhen equilibrium occurred for 0002MCaCl

2 the pH was

recorded as pH0002

then 05mL of 2MCaCl2was added

to each sample and shaken for 3 h and pH was recordedthereafter and designated as pH

005 For each tube 120575pH was

calculated as (pH005minus pH0002

) The pH0was obtained from

the plot of 120575pH against pH0002

The pH0was identified as the

point where 120575pH was zero

223 Determination of Point of Zero Net Charge The pointof zero net charge (PZNC) the pH at which net surfacecharge of the whole system (taking into account both per-manent and variable charge colloids) is zero was obtainedby interpolation of the data from the measurement of chargevariation with pH Charge variation with pHwas determinedby the fingerprint method of Gillman and Sumner [27]Two-gram air-dried soil samples in 50mL preweighed plasticcentrifuge tubes were shaken with 20mL of 01MCaCl

2

for 2 h to saturate the soil with Ca The suspension was

Applied and Environmental Soil Science 3

Table 1 General information on the studied pedons

Pedon Soil classification Relief Physiography Land use Parent material Drainage

1Fine loamy mixed(calcareous) hyperthermicCalcic Haplosalids

Flat Piedmont alluvialplain Saline pasture Calcareous alluvium Imperfectly drained

2Coarse loamy mixed(calcareous) hyperthermicAridic Ustorthents

Almost flat River alluvial plain Bare Calcareous alluvium Well drained

3Fine loamy mixed(calcareous) hyperthermicAridic Ustifluvents

Almost flat Piedmont alluvialplain Plowed Calcareous alluvium Moderately well

drained

4Loamy skeletal mixed(calcareous) hyperthermicAridic Ustifluvents

Almost flat Piedmont alluvialplain Harvested wheat Calcareous alluvium Well drained

5Sandy skeletal mixed(calcareous) hyperthermicAridic Ustifluvents

Almost steep Alluvial-colluvialfan pasture Calcareous alluvium Well drained


Flat River alluvial plain Plowed Calcareous alluvium Moderately welldrained


Almost flat Piedmont alluvialplain Plowed Calcareous alluvium Well drained

8Sandy skeletal mixed(calcareous) hyperthermicAridic Ustorthents

Almost steep Alluvial-colluvialfan Pasture Calcareous alluvium Well drained

centrifuged (3000 rpm 10min) and the supernatant wasdiscardedTheCa saturated soil waswashed twicewith 20mLof 0002MCaCl

2and after the third addition of 20mL of

0002MCaCl2soil suspension was recorded and thereafter

the pH was adjusted to different values by dropwise additionof 01MHCl or saturated Ca(OH)

2 The equilibration of the

pH took several days After the pH was stable the suspen-sion was centrifuged and the supernatant was collected todetermine Ca Al and Cl in the entrained solution Thetubes were then weighed to estimate the volume of entrained0002MCaCl

2

The soil was then extracted with 20mL of 1m NH4NO3

and Ca Al and Cl were determined in the extract Allowingfor entrained Ca Al and Cl the amounts of cation (Ca2+ +Al3+) and anion (Clminus) adsorbed were calculated and equatedwith total negative (CECT) and positive (AEC) chargerespectively The amount of Ca adsorbed was equated withbasic cation exchange capacity (CECB) Aluminum and Cawere determined by AAS and Cl measured by silver nitratetitration method [28] The PZNC was identified as the pHvalue where total negative and positive charges are equalThepermanent charge was estimated as the difference betweenAEC and CECT values at pH

0[29]

224 Mineralogical Analyses Removal of chemical cement-ing agents and separation of the different size fractions ofsoils were carried out according to Mehra and Jackson [21]Kittrick and Hope [30] and Jackson [31] Organic matterand carbonate were removed with 30 H

2O2and 1NHCl

respectively X-ray diffraction (XRD) studies were carriedout on both fine and coarse clay fractions while equalconcentrations of clay suspensions were used for all samplesin order to allow for a more reliable comparison betweenrelative peak intensities for different samples Two drops ofthe prepared suspension were used on each glass slide Theclay samples were finally examined by XRD analysis usinga Philips diffractometer with Co K120572 radiation in order toallow for a more reliable comparison between the relativeheights of peaks in the XRD data The K-saturated sampleswere studied both after drying and heating at 500∘C for4 h to identify kaolinite in the presence of trioctahedralchlorite and samples were also treated with 1NHCl at 80∘Covernight Semiquantitative estimation of clay minerals wasmade by directly converting the diffraction peak areas usingthe method of Karanthanasis and Hajek [32] Selected driedclay particles of the soils were studied under a transmissionelectron microscope (TEM LEO 912 AB) The samplesdispersed in 100 alcohol and 100 120583L of the suspension wasdropped on formvar-coated Cu grids

The soil chemical and mineralogical properties and theirrelationship with the surface charge characteristics wereanalyzed by multiple and simple linear regression using SASand Excel softwares

3 Results and Discussion

31 Field Observation and Soil Classification The soil chem-ical data are shown in Table 1 Pedons 1 3 7 and 4 are soilsdeveloped on the piedmont alluvial plains while pedon 2


Table 2 Some physical properties of the representative profiles

Soil number Depth (cm) Clay Silt Sand Texture+ Structurelowast 120588119887(g cmminus3) Gravel ()

()

1

0ndash25 34 56 10 SiCL WP 154 mdash25ndash78 14 36 50 L Ma 150 mdash78ndash110 32 48 20 CL WG 153 mdash100ndash150 12 22 66 SL Ma 151 mdash

2

0ndash20 10 40 50 L WP 152 mdash20ndash50 10 8 82 LS Sg 153 mdash50ndash100 12 16 72 SL Sg nd 35100ndash150 8 2 90 S Sg 136 mdash

30ndash30 18 38 44 L WG 144 mdash30ndash80 16 37 47 L WG 140 mdash80ndash150 16 12 72 SL Sg 149 mdash

4

0ndash20 10 16 74 SL Sg nd 3020ndash70 8 16 76 SL Sg nd 5070ndash95 14 12 74 SL Sg nd 1095ndash150 12 4 84 LS Sg nd 50

5 0ndash45 18 20 62 SL Sg nd 8545ndash150 24 20 56 SiL Sg nd 65

60ndash42 16 34 50 L WG 141 mdash42ndash88 10 12 78 SL Ma 137 mdash88ndash150 12 26 62 SL Ma 141 mdash

70ndash36 24 42 34 L WG 135 mdash36ndash86 30 50 20 CL WG 139 mdash86ndash150 26 38 36 L WG 141 mdash

80ndash30 12 14 74 SL Sg nd 7030ndash70 10 8 82 LS Sg nd 7570ndash150 14 14 72 SL Sg nd 80

Texture+ SL sandy loam LS loamy sand L loam S sand SiL silty loam SiCL silty clay loam Structurelowast Ma massive Sg single grain WP weak platy WGweak granular nd no determine

and 6 are formed on river alluvial plains Pedons 5 and 8are formed on alluvial colluvial fans and sited on a higherslope area All pedons were dug with a maximum depth of150 cm and obvious textural changes throughout the profilewere observed Since the plain is part of an alluvial andcolluvial fan the deposition of materials from the alluvialand colluvial wash varies from time to time creating differenttextural layers This was observed in all the soils studiedwhere the soils textural changes were extreme particularlyfor the silt and sand content There were also variations intheir structures which is also associated with the amountof sand and silt in the soils The soils tend to be massivewhen the silt content is high otherwise the structures wouldbe single grain when the sand content is high The roundednature of these gravels suggests that they were washed anddeposited along part of the plain All soils were weaklydeveloped and evidenced by weak horizon formation in theprofiles Under the arid environment with annual precipita-tion value of less than 200mm and evaporation of more than4000mm one would surely expect to see slow rate of soilpedological development because of very low rate of PET0[33]

The eight representative profiles were classified usingthe USDA Soil Taxonomy [18] All soils are young anddifferentiated by their moisture regime They were identifiedas Calcic Haplosalids Aridic Ustorthents and Aridic Ustiflu-vents (Table 1)

32 Physical Properties The soil physical data are presentedin Table 2 None of the soil physical characteristics showany clear trend with depth In pedon 1 the clay contentdistribution was irregular In pedons 4 5 7 and 8 clayincreases with depths while in pedon 2 it increased onlyuntil the top 100 cm In contrast to the above observationspedon 6 exhibits a remarkable decrease in clay content withsoil depth In pedons 3 and 4 the silt content decreases withdepth The sand size particles are dominant in all pedonsexcept for pedons 1 and 7 but their distribution throughoutthe profile was very irregular The results are consistent withthe nature of alluvial and colluvial deposition that variesfrom time to time Khresat and Qudah [34] also observeda similar deposition trend on studying the Azraq Basin inNortheastern Jordan which is also formed from alluvial andcolluvial deposition


33 Chemical Properties The soil chemical data of the repre-sentative profiles are presented in Table 3 The soils are alka-line and calcareous in nature containing 1983 to 6145CaCO

3throughout the profiles All soils have pH values

above 70 showing that they are alkalineThe average electricalconductivity values exhibited some variations among the soilsstudied placing these soils from slightly saline to saline levelIn pedons 2 4 5 and 8 the soils were noted to be nonsalinewith EC values ranging from 04 to 264 dSmminus1 while soils inpedons 3 6 and 7 were slightly saline with EC values rangingfrom 21 to 7 dSmminus1 Pedon 1 soil was observed to be salinewith EC values ranging from 1811 to 305 dSmminus1 The Nacontent showed slight variability among the soils studied Inpedons 2 5 and 8 the amount of Na was between 04 and68 cmolckg

minus1 as compared to pedons 1 3 4 6 and 7 whichNa ranges between 184 in 20 cmolckg

minus1 The soils howeverare nonsodic with SAR values ranging from 03 to 77 Thecation exchange capacity ranges from 17 to 414 cmolckg

minus1In pedons 1 3 6 and 7 the CEC was between 195 and411 cmolckg

minus1 as compared to pedons 2 4 5 and 8 withvalues of 117 to 215 The organic carbon content was low inall soils which is common for soils of these regions where thevegetation is scarce

The variability of the soil chemical properties againreflects the alluvial and colluvial nature of soil deposition andtheir rocks origin According to Navai [35] the predominantrocks surrounding the study area are limestone dolomite(Jahrom Formation) limestone marl (Aghajari Formation)limestone green marl (Mishan Formation) salt domes (Hor-moze Formation) and conglomerate (Bakhtiari Formation)The weathered rock materials from these formations werewashed to the catchment areas and these contributed to thevariability in the soil physicochemical properties

34 Clay Mineralogy The clay minerals of the examinedsoils are presented in Table 4 Based on 119889-spacing theminerals identified through XRD diffractograms are as fol-lows smectite (1402ndash15 318ndash320 A) palygorskite (104ndash106 634ndash64 323 and 425ndash447 A) chlorite (701ndash711353 A) illite (997ndash1009 498ndash502 A) kaolinite (72ndash73228 A) and sepiolite (1210ndash1211) The presence of smectitewas proven by Mg-saturated clay samples solvated by ethy-lene glycole which expanded due to treatment with Mg-saturated

The common minerals in all samples of the studied areaare smectite palygorskite illite chlorite and kaolinite Kaoli-nite is found in all soils with the exception of pedon 8 Sepi-olite exists in pedons 3 4 6 and 7 The dominance of theseminerals in the arid regions agrees with the results obtainedby Owliaie et al [36] and Emadi et al [37] Palygorskiteand sepiolite are fibrous clays and are considered to be ofauthigenic origin inherited from weathered parent materialsof the surrounding hills and plateaus [33] The presence ofkaolinite inmost soils is probably due to inheritance from theweathering of coarse and fine materials transported from thesurrounding upland zones Itmay also suggest the occurrenceof palygorskite and sepiolite kaolinization that apparentlymay be due to the effect of organic matter decomposition and

fibrous clay destabilization caused by Mg uptake by plants[38]

35 Soil Electrochemical Properties

351 Point of Zero Charge Characteristics The pH0values

varied from 28 in subsurface horizon of pedon 2 to 335 inthe topsoil horizon of pedon 1 (Table 4) and were positivelycorrelated with the Fed content (119903 = 087

lowastlowast 119875 lt 001) whichwas far more than its correlation with the OC percentage (119903 =minus083

lowastlowast 119875 lt 001) The pH0also has a negative significant

correlation with pHH2O (119903 = minus045lowast 119875 lt 005) Hence the

Fed content had more effect on pH0values compared with

theOC content in the soils studiedThe respective pH0values

of organic matter and sesquioxides have been reported todecrease and increase respectively [8 39]

Li and Xu [40] reported that the layer silicate clays (2 1clays) decreased the pH

0values while the 1 1 clay minerals

as kaolinite increased the pH0 Besides Uehara and Gillman

[5] reported that the oxides of Fe andAl have high pH0values

(pH 7ndash9) while silica (SiO2) and organicmatter have low pH

0

values Therefore the low levels of pH0in the present study

were probably related to layer silicate clays (2 1 clays) andhigh pH in all the pedons

The values of 120575pH (pH0minus pHCaCl

2

) indicate the evolutionof positive and negative charges on the variable chargecomponents [11] The greatest values of 120575pH (pH

0minus pHCaCl

2

)were related to subsurface horizon of profile 2 (minus510 units)which agreed with its strongly negative net charge in the fieldconditions (Table 4) The mineralogical data also confirmedthe occurrence of significant amounts of layer silicate min-erals (smectitic type) in this profile (Table 4) Generally thevariations of 120575pH (pH

0minuspHCaCl

2

) for all the studied horizonsshowed a rather high level (between minus425 and minus510 units)(Table 4) which was in accordance with their CEC levels(Table 3) However because of a large quantity of layer silicateminerals (2 1 clays) and a scarcity of 1 1 clays and Fed thisrising trend from surface to subsurface horizons was not sonoticeable

352 Point of Zero Net Charge (PZNC) For all the studiedsoils the PZNC levels were lt2 which was probably due tothe excess negative charge in these soils Gonzales-Batista etal [10] reported that for systems free of permanent chargePZNC should coincide with pH

0 but for systems where

permanent and variable charges coexist PZNC may differfrom pH

0 Usually in the young soils (Entisols or Inceptisols)

PZNC is lower than its pH0and higher than pH

0if the soils

are highly weathered such as Oxisols [41] In addition themodel of Uehara and Gillman [11] and Yu [2] predict thatin soils having constant negative charge the PZNC value islower than pH

0and vice versa None of the charge variation

curves of the samples indicated the PZNC in pH betweenranges of 26 and 6 which was due to the excessive amountof negative charge compared with the positive charge inthese ranges of pH Besides the amount of estimated ZPNCin all the samples was lower than the pH

0 confirming the

presence of the permanent negative charge in these soils


Table3Ch

emicalprop

ertie

softhe

representativ

eprofiles

Soilnu

mber

Depth

(cm)

pHCa

Cl2

pHH2O

pHKC

lΔpH

(KClminusH

2O)

OC

SAR

CCE

EC dSmminus1

CEC

K+Na+

Mg2

+Ca2

+

Fed(

)(125)

cmol

ckgminus

1

1

0ndash25

765

779

760

minus019

034

742137

2985

414

067

2085

65

016

25ndash78

760

776

755

minus021

020

702498

275

263

022

1445

35

015

78ndash110

755

768

750

minus018

023

66

1983

325

334

036

1672

43

014

100ndash

150

770

787

762

minus025

012

772370

1811

313

017

154

52

33

015

2

0ndash20

785

797

780

minus017

018

36

2704

096

215

023

68

48

25

009

20ndash50

790

803

786

minus017

014

37

2755

040

182

022

57

46

22

010

50ndash100

780

795

773

minus022

013

182832

120

154

020

34

43

24

009

100ndash

150

790

794

774

minus020

016

07

2446

093

117

017

1417

23

010

30ndash

3077

579

077

0minus020

037

35

515

428

233

040

7767

28

011

30ndash80

779

793

774

minus019

020

46

5716

700

347

025

121

1032

013

80ndash150

783

797

778

minus021

017

45

5897

548

295

022

108

837

009

4

0ndash20

785

794

780

minus014

033

24

2884

264

176

051

52

47

53

010

20ndash70

793

802

792

minus010

035

30

2885

145

161

018

52

1346

012

70ndash9

578

079

277

5minus017

030

102729

103

144

018

184

1548

011

95ndash150

794

801

790

minus011

043

162798

121

117

015

26

08

43

015

50ndash

4577

578

8772

minus016

035

155820

154

151

021

28

06

65

012

45ndash150

790

804

785

minus019

038

03

5645

037

132

020

04

05

64

013

60ndash

4277

879

771

minus019

029

39

2824

516

275

039

9766

65

009

42ndash88

790

808

786

minus022

033

26

2353

210

195

017

57

48

50

011

88ndash150

789

806

787

minus019

016

48

2536

492

258

023

108

58

45

012

70ndash

3676

878

175

7minus024

037

29

6145

455

243

022

69

51

67

010

36ndash86

780

795

772

minus023

039

21

6041

525

267

024

54

61

64

009

86ndash150

784

798

780

minus018

029

29

6067

496

258

026

7589

45

010

80ndash

3078

079

1776

minus015

024

22

3112

057

168

036

426

43

009

30ndash70

785

789

783

minus006

025

21

3190

080

184

024

38

22

48

006

70ndash150

781

785

778

minus007

026

33

285

066

175

018

627

43

007

OC

organicc

arbo

nSA

Rsodium

adsorptio

nratio

CEC

cationexchange

capacityFe ddith

ionitecitrateb

icarbo

nateC

CEcalcium

carbon

atee

quivalentEC

electric

alcond

uctiv

ity


Table4Re

lativea

bund

ance

ofcla

ymineralandsomee

lectrochem

icalcharacteris

ticso

fthe

soils

studied

Soilnu

mber

Depth

(cm)

Chl

Sme

Pal

IllKa

oSep

Ill-Sme

pH0120575pH

(KClminusH

2O)120575pH

(pH0minusCaC

l 2)120590119901(cmol

ckgminus

1 )120590max(cmol

ckgminus

1 )

1

0ndash25

178

3816

13mdash

lt8

335

minus019

minus465

minus38

minus48

25ndash78

1513

3711

24mdash

mdash320

minus021

minus440

minus273

minus35

78ndash110

2218

357

18mdash

mdash330

minus018

minus425

minus357

minus43

100ndash

150

2022

315

22mdash

mdash320

minus025

minus450

minus292

minus389

2

0ndash20

1616

2518

25mdash

mdash31

5minus017

minus470

minus212

minus295

20ndash50

3722

2412

5mdash

mdash290

minus017

minus500

minus191

minus27

50ndash100

3125

188

8mdash

lt10

300

minus022

minus480

minus143

minus22

100ndash

150

3029

177

9mdash

lt8

280

minus020

minus510

minus154

minus227

30ndash

3010

1533

266

mdashlt10

300

minus020

minus475

minus221

minus32

30ndash80

2121

3020

8mdash

mdash315

minus019

minus469

minus297

minus41

80ndash150

1126

2915

7mdash

lt12

310

minus021

minus446

minus318

minus42

4

0ndash20

238

1635

85

lt5

295

minus014

minus490

minus181

minus34

20ndash70

2014

1424

1810

mdash287

minus010

minus506

minus112

minus255

70ndash9

536

1610

209

9mdash

320

minus017

minus460

minus132

minus22

95ndash150

2720

915

98

lt12

314

minus011

minus480

minus172

minus209

50ndash

4518

1514

337

mdashlt13

311

minus016

minus464

minus159

minus241

45ndash150

2524

2130

mdashmdash

mdash325

minus019

minus465

minus142

minus224

60ndash

4220

1523

307

5mdash

301

minus019

minus477

minus245

minus32

42ndash88

1921

1524

88

lt5

287

minus022

minus503

minus201

minus289

88ndash150

2525

1220

99

mdash290

minus019

minus499

minus243

minus325

70ndash

3628

1432

26mdash

mdashTr

315

minus024

minus438

minus253

minus35

36ndash86

2420

3020

6mdash

mdash310

minus023

minus470

minus234

minus32

86ndash150

1926

1817

911

Tr315

minus018

minus454

minus243

minus34

80ndash

3030

1827

25mdash

mdashmdash

317

minus015

minus463

minus173

minus24

30ndash70

3326

2318

mdashmdash

mdash310

minus006

minus475

minus192

minus255

70ndash150

3430

2016

mdashmdash

mdash298

minus007

minus483

minus184

minus238

ChlchloriteSm

esm

ectitePalpalygorskiteIllilliteK

aokaolin

iteSepsepioliteIll-Smeillite-smectite


These data also agree with their mineralogical information(Table 4)

353 Permanent Negative Charge (120590119901) The 120590

119901has a positive

significant correlation with Fed (119903 = 063lowastlowast 119875 lt 001)Earlier the effects of Fed on the surface charge propertieswere discussed Hamdan et al [42] showed that chargecharacteristics were significantly correlated with soil organicmatter free iron oxides and clay content Sesquioxides haveamphoteric properties that is their surface charge can beareither positive charge in an acid condition or negative chargein an alkaline condition [43]

The 120590119901has a positive significant correlation with clay

content (119903 = 054lowastlowast 119875 lt 001) The results agree well withthose of Sharami et al [6] At high pH OHminus ions interactwith the edge of the clay particles making them neutral ornegatively charged [44]

Themineralogical compositions in these soils weremixedand each clay mineral plays an important role in the totalpermanent charge Although all soils are a mixture of per-manent and variable-charge components whether one or theother dominants depends largely on its mineralogy [45] Forinstance palygorskite has a positive significant correlationwith 120590

119901(119903 = 060lowastlowast 119875 lt 001) Structurally palygorskite

includes alternation of blocks and tunnels that grow alongthe length of the fiber Each structural block is composed oftwo discontinuous tetrahedral sheets of silica that a centraloctahedral sheet sandwiched between them Because of thediscontinuity of the silica sheets silanol groups (Si-OH) arepresent on the surface of the fiber

The 120590119901has a positive significant correlation with OC (119903 =

060lowastlowast 119875 lt 001) Organic matter also acts as an important

source of surface negative charge Oades et al [46] reportedseveral relationships between surface charge characteristicsand organic matter in an Oxisol under rainforest vegetationin Australia Hydroxyl groups of organic matter can alsocontribute to negative charge [2] Shamshuddin and Anda[47] showed that organic carbon in soils is responsible forlowering the pH

0because of the creation of negative surface

charge andor masking of positive surface chargeThe SAR exchangeable Na and exchangeable Mg also

have a positive significant correlation with 120590119901with 119903-values

of 084lowastlowast 092lowastlowast and 082lowastlowast respectivelyThrough alterationof the crystal lattice structure of soil colloids permanentcharge develops when ions of lower valence substitute forions of higher valence [48] The mechanisms of the effectof electrolyte on surface charge of soils are rather complexAccording to the theory of diffuse double layer two mech-anisms may exist The surface of variable charge minerals isone kind of reversible constant potential surface The chargedensity 120575 on this type of surface is proportional to the squareroot of ion concentration 119862 of the solution that is 120575 =119870(119862)12 where 119870 is a constant [28]

The valence ionic radius and thickness of hydrated layerof cations and anions of various electrolytes are differentMorais et al [49] showed that the nature and valence ofthe counterions also influenced the magnitude of the electriccharges on the soil particles For example the quantities of

negative surface charge and net surface charge in MgCl2

MgSO4 and K

2SO4solutions are lower than those in KCl

solutionFurthermore the 120590

119901has a positive significant correlation

with CEC (119903 = 096lowastlowast 119875 lt 001) This demonstrates that theCEC has the highest effect on the 120590

119901 Since organic matter is

low in the soils the CEC is affected by the expandingminerals(eg smectite) [50] and basic exchangeable cations (eg Na)Sollins et al [45] reported that most of the permanent chargein the soils is on the surfaces of layer-silicate clays whichcompose most of the surface area of p-c soils These claysinclude the 2 1 layer-silicates (illite vermiculite and smec-tite) and the 2 2 clays (chlorite)The 1 1 group of kaolin clayshas a small amount of permanent charge on their surface

The pHH2O has a positive significant correlation with the

permanent negative charge (120590119901) (119903 = 072lowastlowast 119875 lt 001)

The pHKCl also has a positive significant correlation with thepermanent negative charge (120590

119901) (119903 = 055lowastlowast 119875 lt 001)

Rashad and Dultz [51] indicated that at low pH the surfacecharge of both clay soil samples (original clay and the organicmatter removed clay soil) had low negative values whichis due to the protonation of variable charge with increasingpH where deprotonation of functional groups occurs thesurface charge becomes more negative Shamshuddin et al[52] reported that the negative charges on the soil surfacewere found to increase significantly with an increase in pHThus when the pH is raised more OHminus are adsorbed ontothe surface or H+ are released into the solution causing anincrease in negative charges

354 Charge Variation with pH Charge (negative andpositive) variations with pH (0002MCaCl

2) for different

horizons of the soils are presented in Figure 2 The inverserelations between both negative and positive charge variationcurves both in surface and between subsurface horizons(having small levels of variable charge components) werenoticeable The results showed that all of the samples showedlarge negative charge over the range of applied pH Thehighest level of negative charge was evident in profile 1 whichwas probably due to high levels of clay content in its surfaceand subsurface horizons and the relation to 2 1 claymineralsThe charge properties did not show any clear trend withdepth Since the plain is part of an alluvial and colluvial fanthe deposition of materials from the alluvial and colluvialwash varies from time to time creating different texturallayers For instance the level of negative charge in horizonCz1 (minus273 cmolckg

minus1) of profile 1 (Calcic Haplosalids) waslower than that of horizon Cyz2 (357 cmolckg

minus1) Hence thesoil electrochemical properties in profile 1 were different fromthe other studied pedons

Profile 4 (horizon C1) has the lowest negative charge (112

cmolckgminus1) which is probably due to low levels of clay content

and the relatively low smectite in this layer Profile 4 alsoshows the lowest levels of negative charge in both surface andsubsurface horizons compared with the other profiles due toits lower CEC clay content and smectite

The negative charge of the soils in the present study isinfluenced by the 2 1 clay minerals where they are prevalent


AEC (adsorbed Cl)CEC (adsorbed Ca)


0

10

61453746538231245

Profile 2 (horizon A)

minus10

minus20

minus30

minus40

Surfa

ce ch

arge

(cm

olck

gminus1)

Profile 4 (horizon Ap)

05

623532423345289212

Surfa

ce ch

arge

(cm

olck

gminus1)

minus10

minus5

minus20

minus15

minus25

minus30

minus35

63657249413425


0

10

minus10

minus20

minus30

minus40

Surfa

ce ch

arge

(cm

olck

gminus1)

Profile 1 (horizon Az)

6154433732270

10

minus10

minus20

minus30

minus40

minus50

minus60

Surfa

ce ch

arge

(cm

olck

gminus1)


6534541362605

minus10

minus5

minus20

minus15

minus25

minus30

Surfa

ce ch

arge

(cm

olck

gminus1)


5654633226723205

minus10

minus5

minus20

minus15

minus25

minus30

Surfa

ce ch

arge

(cm

olck

gminus1)


544764135292420

10

minus10

minus20

minus30

minus40

Surfa

ce ch

arge

(cm

olck

gminus1)


653453829260

10

minus10

minus20

minus30

minus40

Surfa

ce ch

arge

(cm

olck

gminus1)

Figure 2 Charge variation with soil pH (0002MCaCl2) for different horizons

and organic matter accompanied by iron oxide is scarce(Tables 3 and 4) Consequently pH variations could nothave a great influence on the charge curve Therefore forsoil pH (CaCl

2) of 755 the amount of negative charge in

the subsurface horizon of profile 1 is more than the abovehorizon Naidu et al [53] studied the clay mineralogy andsurface charge characteristics of four basaltic soils fromWestern Samoa The level of trace to subordinate amounts ofkaolinminerals was present in these soilsThe surface charge-pH curves followed a constant potential model indicatingthe presence of substantial amounts of pH-dependent charge

In addition they reported that negative charge was presentat pH values as low as 30 and small quantities of positivecharge were detected at pH values as high as 90 Values forPZC ranged from 22 to 39 and these were generally greaterthan the pH

0determined by 120575pH method in their study The

permanent negative charge of the soils is high because themajority of parent materials are limestoneThe results agreedwell with those obtained by Sharami et al [6]

Generally for all the soils examined the ranges ofcharge variation with pH in the surface horizons were morenoticeable than in the subsurface horizons Most of these


variations were observed in the pH ranging from 35 to 50where the curves had a descending trend

The values of anion exchange capacity (AEC) in mostof the studied soils showed small levels which were dueto a shortage of materials having variable charge Howeverorganic matter and kaolinite are present in these soils butthese materials do not enhance the AEC level with respect totheir intrinsic characteristics and soil pH Another reason forthis observation (small level of AEC)was negative adsorption(repulsion) of anions from surfaces with variable chargeAdsorption of anions is one of the important characteristicsof variable-charge soils Owing to the properties of variable-charge soils in chemical and mineralogical compositionsadsorption of anions by these soils would have been moresignificant compared with adsorption by constant-chargesoils [54] Soils having variable charge occupying large areasin tropical and subtropical regions are characterized bycarrying variable amounts of both negative and positivecharges and therefore can adsorb both cations and anions[55] Hence the soils of the present study due to a shortageof materials having variable charge which is a commonproperty of soils from humid regions had small capacitylevels for anion adsorption

4 Conclusion

The soils of the studied area are young dominantly ofAridisols and Entisols Their mineralogy is dominated by the2 1 silicate layer clay minerals Consequently the pH

0and

the PZNC values in the arid soils are low in comparison withtropical soils The pH

0values of all samples are less than pH

under the field condition because of the high pH and thepresence of high amount of 2 1 silicate clay minerals Chargevariation curves in the soils did not give PZNC values withinpH range of 26 to 6 The PZNC values are less than pH

0in

all samples However permanent negative charge (120590119901) is high

in the arid soils because of presence of clay minerals (2 1 and1 1 types) Hence the 120590

119901has a significant positive correlation

with pH CEC OC SAR Na Mg clay and palygorskite Thecharge variation curves showed that the AEC values are smallwith values of lt283 cmolckg

minus1After this study we can recommend the application of

fertilizers based on the amount of negative charges in the soilsstudied

Acknowledgments

The authors are thankful to Universiti Putra Malaysia fortechnical and financial support They also thank membersof the Department of Land Management for providinglaboratory facilities to carry out this study

References

[1] X N Zhang and A Z Zhao ldquoSurface chargerdquo in Chemistry ofVariable Charge Soils T R Yu Ed pp 17ndash63 OxfordUniversityPress New York NY USA 1997

[2] T R Yu Chemistry of Variable Charge Soils Oxford UniversityPress New York NY USA 1997

[3] J Chorover M K Amistadi and O A Chadwick ldquoSurfacecharge evolution of mineral-organic complexes during pedo-genesis in Hawaiian basaltrdquo Geochimica et Cosmochimica Actavol 68 no 23 pp 4859ndash4876 2004

[4] MBarale CMansour F Carrette et al ldquoCharacterization of thesurface charge of oxide particles of PWR primary water circuitsfrom 5 to 320∘Crdquo Journal of NuclearMaterials vol 381 no 3 pp302ndash308 2008

[5] G Uehara and G P Gillman The Mineralogy Chemistry andPhysics of Tropical Soils with Variable Charge Clays West ViewPress Boulder Colo USA 1981

[6] S M Sharami A Forghani A Akbarzadeh and H Ramezan-pour ldquoMineralogical characteristics and related surface chargefluctuations of some selected soils of temperate regions ofnorthern Iranrdquo Clay Minerals vol 45 no 3 pp 327ndash348 2010

[7] M Anda J Shamshuddin C I Fauziah and S R S OmarldquoMineralogy and factors controlling charge development ofthree Oxisols developed from different parent materialsrdquo Geo-derma vol 143 no 1-2 pp 153ndash167 2008

[8] T Hou R Xu D Tiwari and A Zhao ldquoInteraction betweenelectrical double layers of soil colloids and FeAl oxides insuspensionsrdquo Journal of Colloid and Interface Science vol 310no 2 pp 670ndash674 2007

[9] C Taubaso M Dos Santos Afonso and R M Torres SanchezldquoModelling soil surface charge density using mineral composi-tionrdquo Geoderma vol 121 no 1-2 pp 123ndash133 2004

[10] A Gonzales-Batista J M Hernandez-Moreno E Fernandez-Caldas and A J Herbillon ldquoInfluence of silica content on thesurface charge characteristics of allophanic claysrdquo Clays amp ClayMinerals vol 30 no 2 pp 103ndash110 1982

[11] G Uehara and G P Gillman ldquoCharge characteristics of soilswith variable and permanent charge mineralsmdashI Theoryrdquo SoilScience Society of America Journal vol 44 pp 404ndash409 1980

[12] N C Brady and R R Weil The Nature and Properties of SoilsPrentice Hall Upper Sadller River NJ USA 13th edition 2002

[13] G Bellini M E Sumner D E Radcliffe and N P QafokuldquoAnion transport through columns of highly weathered acidsoil adsorption and retardationrdquo Soil Science Society of AmericaJournal vol 60 no 1 pp 132ndash137 1996

[14] D J Burdon ldquoHydrogeological conditions in the Middle EastrdquoQuarterly Journal of Engineering Geology vol 15 no 2 pp 71ndash82 1982

[15] M H Banaei ldquoSoil moisture and temperature region map ofIranrdquo Soil and Water Research Institute Ministry of Agricul-ture Tehran Iran 1998

[16] A H Moghimi ldquoSemi-detailed soil survey and classification inAshkara plain Iranrdquo Soil andWater research institute Ministryof Agriculture Tehran Iran 2002

[17] Soil Survey Staff ldquoSoil survey laboratory methods manualrdquo Soilsurvey investigation report No 42 version 4 Washington DCUSA 2004

[18] Soil Survey Staff ldquoKeys to Soil Taxonomyrdquo US Department ofAgriculture NRCS 2010

[19] G W Gee and J W Bauder ldquoParticle size analysisrdquo inMethodsof Soil Analysis A Klute Ed vol 9 of Agronomy Monograph 9ASA and SSSA Madison Wis USA 2nd edition 1986

[20] A Walkley and C A Black ldquoA critical examination of rapidmethod for determining organic carbon in soils effect of varia-tions in digestion conditions and of inorganic soil constituentsrdquoSoil Science vol 63 pp 251ndash263 1947


[21] O P Mehra and M L Jackson ldquoIron oxide removal from soilsand clays by a dithionitecitrate system buffered with sodiumbicarbonaterdquo Clay Minerals vol 7 pp 317ndash327 1980

[22] M K Conyers and B G Davey ldquoObservations on some routinemethods for soil pH determinationrdquo Soil Science vol 145 no 1pp 29ndash36 1988

[23] L P Van Reeuwijk ldquoProcedures for soil analysisrdquo in Proceed-ings of the International Soil Conference Information CentreNetherlands 2002

[24] G R Blake and K H Hartge ldquoBulk densityrdquo inMethods of SoilAnalysismdashPart 1 Physical and Mineralogical Methods A KluteEd Agronomy Monograph 9 ASA and SSSA Madison WisUSA 2nd edition 1986

[25] Salinity Laboratory Staff Diagnosis and Improvement of Salineand Alkali Soils USDA Handbook No 60 Washington DCUSA 1954

[26] L E Allison and C D Moodi ldquoCarbonaterdquo in Methods of SoilAnalysis C A Black Ed vol 9 of Agronomy pp 1379ndash13961965

[27] G P Gillman and M E Sumner ldquoSurface charge character-ization and soil solution composition of four soils from theSouthern Piedmont in Georgiardquo Soil Science Society of AmericaJournal vol 51 no 3 pp 589ndash594 1987

[28] H Van Olphen An Introduction to Clay Colloid ChemistryInterscience New York NY USA 2nd edition 1977

[29] G P Gillman and G Uehara ldquoCharge characteristics of soilswith variable and permanent charge mineralsmdashII Experimen-talrdquo Soil Science Society of America Journal vol 44 pp 252ndash2551980

[30] J A Kittrick and E W Hope ldquoA procedure for the particle sizeseparation of soils for X-ray diffraction analysisrdquo Soil Sciencevol 96 pp 312ndash325 1963

[31] M L Jackson Soil Chemical Analysis AdvancedCourse Univer-sity of Wisconsin College of Agriculture Department of soilsMadison Wis USA 1975

[32] A D Karathanasis and B F Hajek ldquoRevised methods for rapidquantitative determination ofminerals in soil claysrdquo Soil ScienceSociety of America Journal vol 46 no 2 pp 419ndash425 1982

[33] F Khormali and A Abtahi ldquoOrigin and distribution of clayminerals in calcareous arid and semi-arid soils of Fars Provincesouthern Iranrdquo Clay Minerals vol 38 no 4 pp 511ndash528 2003

[34] S A Khresat and E A Qudah ldquoFormation and properties ofaridic soils of Azraq Basin in northeastern Jordanrdquo Journal ofArid Environments vol 64 no 1 pp 116ndash136 2006

[35] I Navai ldquoExplanatory Text of the Hajiabad Quadrangle map1250000rdquo Geological Survey of Iran 1976

[36] H R Owliaie A Abtahi and R J Heck ldquoPedogenesis andclay mineralogical investigation of soils formed on gypsiferousand calcareous materials on a transect southwestern IranrdquoGeoderma vol 134 no 1-2 pp 62ndash81 2006

[37] M Emadi M Baghernejad H Memarian M Saffari and HFathi ldquoGenesis and clay mineralogical investigation of highlycalcareous soils in semi-arid regions of Southern Iranrdquo Journalof Applied Sciences vol 8 no 2 pp 288ndash294 2008

[38] H Khademi and J M Arocena ldquoKaolinite formation frompalygorskite and sepiolite in rhizosphere soilsrdquo Clays and ClayMinerals vol 56 no 4 pp 429ndash436 2008

[39] CA Coles andRN Yong ldquoHumic acid preparation propertiesand interactions with metals lead and cadmiumrdquo EngineeringGeology vol 85 no 1-2 pp 26ndash32 2006

[40] S-Z Li and R-K Xu ldquoElectrical double layersrsquo interactionbetween oppositely charged particles as related to surface chargedensity and ionic strengthrdquoColloids and Surfaces A vol 326 no3 pp 157ndash161 2008

[41] E Tessens and J Shamshuddin Quantitative RelationshipsbetweenMineralogy and Properties of Tropical Soils UPMPressSerdang Malaysia 1983

[42] J Hamdan B Ruhana and C P Burnham ldquoSurface chargedistribution of Three deep regoliths from Peninsular MalaysiardquoJournal of Sustainable Agriculture vol 18 no 1 pp 5ndash22 2001

[43] N P Qafoku E Van Ranst A Noble and A Baert ldquoVariablecharge soils their mineralogy chemistry and managementrdquoAdvances in Agronomy vol 84 pp 159ndash215 2004

[44] G SpositoTheChemistry of Soils OxfordUniversity Press NewYork NY USA 1989

[45] P Sollins G P Robertson and G Uehara ldquoNutrient mobility invariable- and permanent-charge soilsrdquo Biogeochemistry vol 6no 3 pp 181ndash199 1988

[46] J M Oades G P Gillman and G Uehara ldquoInteractions of soilorganic and variable-charge claysrdquo in Dynamics of Soil OrganicMatter in Tropical Ecosystems D C Coleman J M Oadesand G Uehara Eds pp 69ndash95 University of Hawaii PressHonolulu Hawaii USA 1989

[47] J Shamshuddin and M Anda ldquoCharge properties of soilsin Malaysia dominated by kaolinite gibbsite goethite andhematiterdquo Bulletin of the Geological Society of Malaysia vol 54pp 27ndash31 2008

[48] J B Yavitt and S J Wright ldquoCharge characteristics of soil ina lowland tropical moist forest in Panama in response to dry-season irrigationrdquo Australian Journal of Soil Research vol 40no 2 pp 269ndash281 2002

[49] F I Morais A L Paga and L J Lund ldquoThe effect of pHsalt concentration and nature of electrolytes on the chargecharacteristics of Brazilian tropical soilsrdquo Soil Science Society ofAmerica Journal vol 40 pp 521ndash527 1976

[50] C A Igwe F O R Akamigbo and J S C Mbagwu ldquoChemicaland mineralogical properties of soils in southeastern Nigeria inrelation to aggregate stabilityrdquo Geoderma vol 92 no 1-2 pp111ndash123 1999

[51] M Rashad and S Dultz ldquoDecisive factors of clay dispersionin alluvial soils of the Nile River Deltamdasha study on surfacecharge propertiesrdquoAmerican-Eurasian Journal of Agricultural ampEnvironmental Sciences vol 2 pp 213ndash219 2007

[52] J Shamshuddin S Paramananthan and N Mokhtar ldquoMineral-ogy and surface charge properties of two acid sulfate soils fromPeninsular Malaysiardquo Pertanika vol 9 pp 167ndash176 1986

[53] R Naidu R J Morrison L Janik and M Asghar ldquoClaymineralogy and surface charge characteristics of basaltic soilsfromWestern SamoardquoClayMinerals vol 32 no 4 pp 545ndash5561997

[54] J Li R Xu S Xiao and G Ji ldquoEffect of low-molecular-weightorganic anions on exchangeable aluminum capacity of variablecharge soilsrdquo Journal of Colloid and Interface Science vol 284no 2 pp 393ndash399 2005

[55] R Xu A Zhao and G Ji ldquoEffect of low-molecular-weightorganic anions on surface charge of variable charge soilsrdquoJournal of Colloid and Interface Science vol 264 no 2 pp 322ndash326 2003

Submit your manuscripts athttpwwwhindawicom

Forestry ResearchInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

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Journal of



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Applied ampEnvironmentalSoil Science

Volume 2014

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Atmospheric SciencesInternational Journal of



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Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

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Geological ResearchJournal of

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OceanographyInternational Journal of


The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Journal of Computational Environmental SciencesHindawi Publishing Corporationhttpwwwhindawicom Volume 2014


ClimatologyJournal of


problems of soils of the arid regions For example in thearid regions the NH

4

+ fixed by soil particles and leachedout as NO

3

minus form due to high permanent negative charge inthe surface of soil particles [12] in comparison with highlyweathered soils whereNO

3

minus leaching because of high positivecharge present in the soils [13] The objectives of this studywere to determine the physicochemical and mineralogicalproperties the pH

0 PZNC and permanent negative charge

(120590119901) and to determine the relation between pH

0and 120590

119901with

characteristics of arid soils in Southeastern Iran

2 Materials and Methods

21 Description of the Study Area The studied area is locatedin the province of Hormozgan Southeastern Iran betweenlatitude 28∘81015840 and 28∘151015840 North and longitudes 56∘51015840 and 56∘151015840 East (Figure 1) The climate is arid with an average annualprecipitation of about 162mm and evaporation of 4243mmBurdon [14] reported that the estimated potential evapotran-spiration could be in excess of 50 times the mean annual pre-cipitation The temperature regime is hyperthermic with anaridic and usticmoisture regimes [15]The sedimentary rocksaccompanyingmarine deposits of the Tertiary age formed thecatchment area which is predominantly composed of thickalluvial and colluvial materials occasionally deposited by theDehshaykh River for the past thousands of years The riveris dry most of the time except during heavy downfall Thecatchment is currently cultivated with wheat maize potatoand watermelon as important agricultural crops [16]

Eight pedons were selected among the dug profilesrepresenting alluvial fan and colluvial deposits along theslope area of the catchment by geopedology approach anddifferent soil horizons were sampled for laboratory analysisThe morphological properties of the soils were described inthe field [17] and were classified according to the USDA SoilTaxonomy [18]

22 Methods

221 Physical and Chemical Analyses Field study and sam-ples collectionwere carried out in the summer season of 2009(August to September) The soil samples were air-dried andsieved with a 2mm sieve and kept in plastic bags prior toanalysis

The particle size analysis was carried out by the pipettemethod [19] Organic matter content of the soil was deter-mined by the wet combustion procedure of Walkley andBlack [20] and Fe

2O3was estimated by the dithionite-citrate-

bicarbonate method [21] The pH was measured in thesupernatant suspension of 1 1 soil water suspension pH [17]1 25 liquid 001M CaCl

2solution (pHCaCl

2

) [22] and 1 25soil H

2O (pHH

2O) and 1 25 soil 1MKCl solution (pHKCl)

[23]Thebulk density (120588119887) was estimated by coremethod [24]

and the electrical conductivity (EC) analysis wasmeasured inthe saturated extract [25] The calcium carbonate equivalent(lime) was measured by acid neutralization [26] exchange-able cations content and the cation exchange capacity (CEC)of the soils were determined by the 1M ammonium acetate

40∘

35∘

30∘

25∘

45∘

50∘

55∘

60∘

65∘

N

Paki

stan

Afg

hani

stan

Turkmenistan

Study area

Bandarabbas

Caspian Sea

Tehran

Iran

Shiraz

Persian

Turk

ey

Iraq

Kuwait

Saudi ArabiaGulf

Figure 1 Location of the study area

(pH 7) method The exchangeable cations (Ca2+ and Mg2+)in the leachate were determined by atomic absorption spec-trophotometer (AAS Perkin-Elmer 047-1705) whereas K+andNa+ weremeasured by flame spectrophotometerThe soilsolution data (Na+ Ca2+ Mg2+ given in cmolckg

minus1) was usedto calculate the sodium adsorption ratio (SAR) where SAR =Na+[(Ca2+ + Mg2+)2]minus05

222 Determination of Point of Zero Charge Point of zerocharge (PZC) denoted as pH

0 is defined as the pH at which

the net charge on the variable charge components is zeroand was determined according to the method of Gillman andSumner [27] Six portions of 2 g of 2mm air-dried sampleswere weighed into 50mL plastic centrifuge tubes and shakenwith 20mL of 01M CaCl

2for 2 h to saturate the soil with

Ca The suspension was centrifuged (3000 rpm 10min) andthe supernatant was discarded The Ca saturated soil waswashed twice with 20mL of 0002MCaCl

2and after the

third addition of 20mL of 0002CaCl2 the pH was adjusted

to six values of 01MHCl in the range of 35 to 6mL bydropwise addition Equilibration of the pH took several daysWhen equilibrium occurred for 0002MCaCl

2 the pH was

recorded as pH0002

then 05mL of 2MCaCl2was added

to each sample and shaken for 3 h and pH was recordedthereafter and designated as pH

005 For each tube 120575pH was

calculated as (pH005minus pH0002

) The pH0was obtained from

the plot of 120575pH against pH0002

The pH0was identified as the

point where 120575pH was zero

223 Determination of Point of Zero Net Charge The pointof zero net charge (PZNC) the pH at which net surfacecharge of the whole system (taking into account both per-manent and variable charge colloids) is zero was obtainedby interpolation of the data from the measurement of chargevariation with pH Charge variation with pHwas determinedby the fingerprint method of Gillman and Sumner [27]Two-gram air-dried soil samples in 50mL preweighed plasticcentrifuge tubes were shaken with 20mL of 01MCaCl

2

for 2 h to saturate the soil with Ca The suspension was










drained

















2



0[29]


2O2and 1NHCl








()

1


2



4




































0




2


0minus pHCaCl

2


0minuspHCaCl

2







0if the soils




0 confirming the



Table3Ch

emicalprop

ertie

softhe

representativ

eprofiles

Soilnu

mber

Depth

(cm)

pHCa

Cl2

pHH2O

pHKC

lΔpH

(KClminusH

2O)

OC

SAR

CCE

EC dSmminus1

CEC

K+Na+

Mg2

+Ca2

+

Fed(

)(125)

cmol

ckgminus

1

1

0ndash25

765

779

760

minus019

034

742137

2985

414

067

2085

65

016

25ndash78

760

776

755

minus021

020

702498

275

263

022

1445

35

015

78ndash110

755

768

750

minus018

023

66

1983

325

334

036

1672

43

014

100ndash

150

770

787

762

minus025

012

772370

1811

313

017

154

52

33

015

2

0ndash20

785

797

780

minus017

018

36

2704

096

215

023

68

48

25

009

20ndash50

790

803

786

minus017

014

37

2755

040

182

022

57

46

22

010

50ndash100

780

795

773

minus022

013

182832

120

154

020

34

43

24

009

100ndash

150

790

794

774

minus020

016

07

2446

093

117

017

1417

23

010

30ndash

3077

579

077

0minus020

037

35

515

428

233

040

7767

28

011

30ndash80

779

793

774

minus019

020

46

5716

700

347

025

121

1032

013

80ndash150

783

797

778

minus021

017

45

5897

548

295

022

108

837

009

4

0ndash20

785

794

780

minus014

033

24

2884

264

176

051

52

47

53

010

20ndash70

793

802

792

minus010

035

30

2885

145

161

018

52

1346

012

70ndash9

578

079

277

5minus017

030

102729

103

144

018

184

1548

011

95ndash150

794

801

790

minus011

043

162798

121

117

015

26

08

43

015

50ndash

4577

578

8772

minus016

035

155820

154

151

021

28

06

65

012

45ndash150

790

804

785

minus019

038

03

5645

037

132

020

04

05

64

013

60ndash

4277

879

771

minus019

029

39

2824

516

275

039

9766

65

009

42ndash88

790

808

786

minus022

033

26

2353

210

195

017

57

48

50

011

88ndash150

789

806

787

minus019

016

48

2536

492

258

023

108

58

45

012

70ndash

3676

878

175

7minus024

037

29

6145

455

243

022

69

51

67

010

36ndash86

780

795

772

minus023

039

21

6041

525

267

024

54

61

64

009

86ndash150

784

798

780

minus018

029

29

6067

496

258

026

7589

45

010

80ndash

3078

079

1776

minus015

024

22

3112

057

168

036

426

43

009

30ndash70

785

789

783

minus006

025

21

3190

080

184

024

38

22

48

006

70ndash150

781

785

778

minus007

026

33

285

066

175

018

627

43

007

OC

organicc

arbo

nSA

Rsodium

adsorptio

nratio

CEC

cationexchange

capacityFe ddith

ionitecitrateb

icarbo

nateC

CEcalcium

carbon

atee

quivalentEC

electric

alcond

uctiv

ity


Table4Re

lativea

bund

ance

ofcla

ymineralandsomee

lectrochem

icalcharacteris

ticso

fthe

soils

studied

Soilnu

mber

Depth

(cm)

Chl

Sme

Pal

IllKa

oSep

Ill-Sme

pH0120575pH

(KClminusH

2O)120575pH

(pH0minusCaC

l 2)120590119901(cmol

ckgminus

1 )120590max(cmol

ckgminus

1 )

1

0ndash25

178

3816

13mdash

lt8

335

minus019

minus465

minus38

minus48

25ndash78

1513

3711

24mdash

mdash320

minus021

minus440

minus273

minus35

78ndash110

2218

357

18mdash

mdash330

minus018

minus425

minus357

minus43

100ndash

150

2022

315

22mdash

mdash320

minus025

minus450

minus292

minus389

2

0ndash20

1616

2518

25mdash

mdash31

5minus017

minus470

minus212

minus295

20ndash50

3722

2412

5mdash

mdash290

minus017

minus500

minus191

minus27

50ndash100

3125

188

8mdash

lt10

300

minus022

minus480

minus143

minus22

100ndash

150

3029

177

9mdash

lt8

280

minus020

minus510

minus154

minus227

30ndash

3010

1533

266

mdashlt10

300

minus020

minus475

minus221

minus32

30ndash80

2121

3020

8mdash

mdash315

minus019

minus469

minus297

minus41

80ndash150

1126

2915

7mdash

lt12

310

minus021

minus446

minus318

minus42

4

0ndash20

238

1635

85

lt5

295

minus014

minus490

minus181

minus34

20ndash70

2014

1424

1810

mdash287

minus010

minus506

minus112

minus255

70ndash9

536

1610

209

9mdash

320

minus017

minus460

minus132

minus22

95ndash150

2720

915

98

lt12

314

minus011

minus480

minus172

minus209

50ndash

4518

1514

337

mdashlt13

311

minus016

minus464

minus159

minus241

45ndash150

2524

2130

mdashmdash

mdash325

minus019

minus465

minus142

minus224

60ndash

4220

1523

307

5mdash

301

minus019

minus477

minus245

minus32

42ndash88

1921

1524

88

lt5

287

minus022

minus503

minus201

minus289

88ndash150

2525

1220

99

mdash290

minus019

minus499

minus243

minus325

70ndash

3628

1432

26mdash

mdashTr

315

minus024

minus438

minus253

minus35

36ndash86

2420

3020

6mdash

mdash310

minus023

minus470

minus234

minus32

86ndash150

1926

1817

911

Tr315

minus018

minus454

minus243

minus34

80ndash

3030

1827

25mdash

mdashmdash

317

minus015

minus463

minus173

minus24

30ndash70

3326

2318

mdashmdash

mdash310

minus006

minus475

minus192

minus255

70ndash150

3430

2016

mdashmdash

mdash298

minus007

minus483

minus184

minus238

ChlchloriteSm

esm


aokaolin





















MgSO4 and K










119901) (119903 = 055lowastlowast 119875 lt 001)



2) for different











0

10

61453746538231245


minus10

minus20

minus30

minus40

Surfa

ce ch

arge

(cm

olck

gminus1)


05

623532423345289212

Surfa

ce ch

arge

(cm

olck

gminus1)

minus10

minus5

minus20

minus15

minus25

minus30

minus35

63657249413425


0

10

minus10

minus20

minus30

minus40

Surfa

ce ch

arge

(cm

olck

gminus1)


6154433732270

10

minus10

minus20

minus30

minus40

minus50

minus60

Surfa

ce ch

arge

(cm

olck

gminus1)


6534541362605

minus10

minus5

minus20

minus15

minus25

minus30

Surfa

ce ch

arge

(cm

olck

gminus1)


5654633226723205

minus10

minus5

minus20

minus15

minus25

minus30

Surfa

ce ch

arge

(cm

olck

gminus1)


544764135292420

10

minus10

minus20

minus30

minus40

Surfa

ce ch

arge

(cm

olck

gminus1)


653453829260

10

minus10

minus20

minus30

minus40

Surfa

ce ch

arge

(cm

olck

gminus1)












4 Conclusion


0and




0in







Acknowledgments


References





























































Journal of












Volume 2014

Advances in









Geophysics























drained

















2



0[29]


2O2and 1NHCl








()

1


2



4




































0




2


0minus pHCaCl

2


0minuspHCaCl

2







0if the soils




0 confirming the



Table3Ch

emicalprop

ertie

softhe

representativ

eprofiles

Soilnu

mber

Depth

(cm)

pHCa

Cl2

pHH2O

pHKC

lΔpH

(KClminusH

2O)

OC

SAR

CCE

EC dSmminus1

CEC

K+Na+

Mg2

+Ca2

+

Fed(

)(125)

cmol

ckgminus

1

1

0ndash25

765

779

760

minus019

034

742137

2985

414

067

2085

65

016

25ndash78

760

776

755

minus021

020

702498

275

263

022

1445

35

015

78ndash110

755

768

750

minus018

023

66

1983

325

334

036

1672

43

014

100ndash

150

770

787

762

minus025

012

772370

1811

313

017

154

52

33

015

2

0ndash20

785

797

780

minus017

018

36

2704

096

215

023

68

48

25

009

20ndash50

790

803

786

minus017

014

37

2755

040

182

022

57

46

22

010

50ndash100

780

795

773

minus022

013

182832

120

154

020

34

43

24

009

100ndash

150

790

794

774

minus020

016

07

2446

093

117

017

1417

23

010

30ndash

3077

579

077

0minus020

037

35

515

428

233

040

7767

28

011

30ndash80

779

793

774

minus019

020

46

5716

700

347

025

121

1032

013

80ndash150

783

797

778

minus021

017

45

5897

548

295

022

108

837

009

4

0ndash20

785

794

780

minus014

033

24

2884

264

176

051

52

47

53

010

20ndash70

793

802

792

minus010

035

30

2885

145

161

018

52

1346

012

70ndash9

578

079

277

5minus017

030

102729

103

144

018

184

1548

011

95ndash150

794

801

790

minus011

043

162798

121

117

015

26

08

43

015

50ndash

4577

578

8772

minus016

035

155820

154

151

021

28

06

65

012

45ndash150

790

804

785

minus019

038

03

5645

037

132

020

04

05

64

013

60ndash

4277

879

771

minus019

029

39

2824

516

275

039

9766

65

009

42ndash88

790

808

786

minus022

033

26

2353

210

195

017

57

48

50

011

88ndash150

789

806

787

minus019

016

48

2536

492

258

023

108

58

45

012

70ndash

3676

878

175

7minus024

037

29

6145

455

243

022

69

51

67

010

36ndash86

780

795

772

minus023

039

21

6041

525

267

024

54

61

64

009

86ndash150

784

798

780

minus018

029

29

6067

496

258

026

7589

45

010

80ndash

3078

079

1776

minus015

024

22

3112

057

168

036

426

43

009

30ndash70

785

789

783

minus006

025

21

3190

080

184

024

38

22

48

006

70ndash150

781

785

778

minus007

026

33

285

066

175

018

627

43

007

OC

organicc

arbo

nSA

Rsodium

adsorptio

nratio

CEC

cationexchange

capacityFe ddith

ionitecitrateb

icarbo

nateC

CEcalcium

carbon

atee

quivalentEC

electric

alcond

uctiv

ity


Table4Re

lativea

bund

ance

ofcla

ymineralandsomee

lectrochem

icalcharacteris

ticso

fthe

soils

studied

Soilnu

mber

Depth

(cm)

Chl

Sme

Pal

IllKa

oSep

Ill-Sme

pH0120575pH

(KClminusH

2O)120575pH

(pH0minusCaC

l 2)120590119901(cmol

ckgminus

1 )120590max(cmol

ckgminus

1 )

1

0ndash25

178

3816

13mdash

lt8

335

minus019

minus465

minus38

minus48

25ndash78

1513

3711

24mdash

mdash320

minus021

minus440

minus273

minus35

78ndash110

2218

357

18mdash

mdash330

minus018

minus425

minus357

minus43

100ndash

150

2022

315

22mdash

mdash320

minus025

minus450

minus292

minus389

2

0ndash20

1616

2518

25mdash

mdash31

5minus017

minus470

minus212

minus295

20ndash50

3722

2412

5mdash

mdash290

minus017

minus500

minus191

minus27

50ndash100

3125

188

8mdash

lt10

300

minus022

minus480

minus143

minus22

100ndash

150

3029

177

9mdash

lt8

280

minus020

minus510

minus154

minus227

30ndash

3010

1533

266

mdashlt10

300

minus020

minus475

minus221

minus32

30ndash80

2121

3020

8mdash

mdash315

minus019

minus469

minus297

minus41

80ndash150

1126

2915

7mdash

lt12

310

minus021

minus446

minus318

minus42

4

0ndash20

238

1635

85

lt5

295

minus014

minus490

minus181

minus34

20ndash70

2014

1424

1810

mdash287

minus010

minus506

minus112

minus255

70ndash9

536

1610

209

9mdash

320

minus017

minus460

minus132

minus22

95ndash150

2720

915

98

lt12

314

minus011

minus480

minus172

minus209

50ndash

4518

1514

337

mdashlt13

311

minus016

minus464

minus159

minus241

45ndash150

2524

2130

mdashmdash

mdash325

minus019

minus465

minus142

minus224

60ndash

4220

1523

307

5mdash

301

minus019

minus477

minus245

minus32

42ndash88

1921

1524

88

lt5

287

minus022

minus503

minus201

minus289

88ndash150

2525

1220

99

mdash290

minus019

minus499

minus243

minus325

70ndash

3628

1432

26mdash

mdashTr

315

minus024

minus438

minus253

minus35

36ndash86

2420

3020

6mdash

mdash310

minus023

minus470

minus234

minus32

86ndash150

1926

1817

911

Tr315

minus018

minus454

minus243

minus34

80ndash

3030

1827

25mdash

mdashmdash

317

minus015

minus463

minus173

minus24

30ndash70

3326

2318

mdashmdash

mdash310

minus006

minus475

minus192

minus255

70ndash150

3430

2016

mdashmdash

mdash298

minus007

minus483

minus184

minus238

ChlchloriteSm

esm


aokaolin





















MgSO4 and K










119901) (119903 = 055lowastlowast 119875 lt 001)



2) for different











0

10

61453746538231245


minus10

minus20

minus30

minus40

Surfa

ce ch

arge

(cm

olck

gminus1)


05

623532423345289212

Surfa

ce ch

arge

(cm

olck

gminus1)

minus10

minus5

minus20

minus15

minus25

minus30

minus35

63657249413425


0

10

minus10

minus20

minus30

minus40

Surfa

ce ch

arge

(cm

olck

gminus1)


6154433732270

10

minus10

minus20

minus30

minus40

minus50

minus60

Surfa

ce ch

arge

(cm

olck

gminus1)


6534541362605

minus10

minus5

minus20

minus15

minus25

minus30

Surfa

ce ch

arge

(cm

olck

gminus1)


5654633226723205

minus10

minus5

minus20

minus15

minus25

minus30

Surfa

ce ch

arge

(cm

olck

gminus1)


544764135292420

10

minus10

minus20

minus30

minus40

Surfa

ce ch

arge

(cm

olck

gminus1)


653453829260

10

minus10

minus20

minus30

minus40

Surfa

ce ch

arge

(cm

olck

gminus1)












4 Conclusion


0and




0in







Acknowledgments


References





























































Journal of












Volume 2014

Advances in









Geophysics

















()

1


2



4




































0




2


0minus pHCaCl

2


0minuspHCaCl

2







0if the soils




0 confirming the



Table3Ch

emicalprop

ertie

softhe

representativ

eprofiles

Soilnu

mber

Depth

(cm)

pHCa

Cl2

pHH2O

pHKC

lΔpH

(KClminusH

2O)

OC

SAR

CCE

EC dSmminus1

CEC

K+Na+

Mg2

+Ca2

+

Fed(

)(125)

cmol

ckgminus

1

1

0ndash25

765

779

760

minus019

034

742137

2985

414

067

2085

65

016

25ndash78

760

776

755

minus021

020

702498

275

263

022

1445

35

015

78ndash110

755

768

750

minus018

023

66

1983

325

334

036

1672

43

014

100ndash

150

770

787

762

minus025

012

772370

1811

313

017

154

52

33

015

2

0ndash20

785

797

780

minus017

018

36

2704

096

215

023

68

48

25

009

20ndash50

790

803

786

minus017

014

37

2755

040

182

022

57

46

22

010

50ndash100

780

795

773

minus022

013

182832

120

154

020

34

43

24

009

100ndash

150

790

794

774

minus020

016

07

2446

093

117

017

1417

23

010

30ndash

3077

579

077

0minus020

037

35

515

428

233

040

7767

28

011

30ndash80

779

793

774

minus019

020

46

5716

700

347

025

121

1032

013

80ndash150

783

797

778

minus021

017

45

5897

548

295

022

108

837

009

4

0ndash20

785

794

780

minus014

033

24

2884

264

176

051

52

47

53

010

20ndash70

793

802

792

minus010

035

30

2885

145

161

018

52

1346

012

70ndash9

578

079

277

5minus017

030

102729

103

144

018

184

1548

011

95ndash150

794

801

790

minus011

043

162798

121

117

015

26

08

43

015

50ndash

4577

578

8772

minus016

035

155820

154

151

021

28

06

65

012

45ndash150

790

804

785

minus019

038

03

5645

037

132

020

04

05

64

013

60ndash

4277

879

771

minus019

029

39

2824

516

275

039

9766

65

009

42ndash88

790

808

786

minus022

033

26

2353

210

195

017

57

48

50

011

88ndash150

789

806

787

minus019

016

48

2536

492

258

023

108

58

45

012

70ndash

3676

878

175

7minus024

037

29

6145

455

243

022

69

51

67

010

36ndash86

780

795

772

minus023

039

21

6041

525

267

024

54

61

64

009

86ndash150

784

798

780

minus018

029

29

6067

496

258

026

7589

45

010

80ndash

3078

079

1776

minus015

024

22

3112

057

168

036

426

43

009

30ndash70

785

789

783

minus006

025

21

3190

080

184

024

38

22

48

006

70ndash150

781

785

778

minus007

026

33

285

066

175

018

627

43

007

OC

organicc

arbo

nSA

Rsodium

adsorptio

nratio

CEC

cationexchange

capacityFe ddith

ionitecitrateb

icarbo

nateC

CEcalcium

carbon

atee

quivalentEC

electric

alcond

uctiv

ity


Table4Re

lativea

bund

ance

ofcla

ymineralandsomee

lectrochem

icalcharacteris

ticso

fthe

soils

studied

Soilnu

mber

Depth

(cm)

Chl

Sme

Pal

IllKa

oSep

Ill-Sme

pH0120575pH

(KClminusH

2O)120575pH

(pH0minusCaC

l 2)120590119901(cmol

ckgminus

1 )120590max(cmol

ckgminus

1 )

1

0ndash25

178

3816

13mdash

lt8

335

minus019

minus465

minus38

minus48

25ndash78

1513

3711

24mdash

mdash320

minus021

minus440

minus273

minus35

78ndash110

2218

357

18mdash

mdash330

minus018

minus425

minus357

minus43

100ndash

150

2022

315

22mdash

mdash320

minus025

minus450

minus292

minus389

2

0ndash20

1616

2518

25mdash

mdash31

5minus017

minus470

minus212

minus295

20ndash50

3722

2412

5mdash

mdash290

minus017

minus500

minus191

minus27

50ndash100

3125

188

8mdash

lt10

300

minus022

minus480

minus143

minus22

100ndash

150

3029

177

9mdash

lt8

280

minus020

minus510

minus154

minus227

30ndash

3010

1533

266

mdashlt10

300

minus020

minus475

minus221

minus32

30ndash80

2121

3020

8mdash

mdash315

minus019

minus469

minus297

minus41

80ndash150

1126

2915

7mdash

lt12

310

minus021

minus446

minus318

minus42

4

0ndash20

238

1635

85

lt5

295

minus014

minus490

minus181

minus34

20ndash70

2014

1424

1810

mdash287

minus010

minus506

minus112

minus255

70ndash9

536

1610

209

9mdash

320

minus017

minus460

minus132

minus22

95ndash150

2720

915

98

lt12

314

minus011

minus480

minus172

minus209

50ndash

4518

1514

337

mdashlt13

311

minus016

minus464

minus159

minus241

45ndash150

2524

2130

mdashmdash

mdash325

minus019

minus465

minus142

minus224

60ndash

4220

1523

307

5mdash

301

minus019

minus477

minus245

minus32

42ndash88

1921

1524

88

lt5

287

minus022

minus503

minus201

minus289

88ndash150

2525

1220

99

mdash290

minus019

minus499

minus243

minus325

70ndash

3628

1432

26mdash

mdashTr

315

minus024

minus438

minus253

minus35

36ndash86

2420

3020

6mdash

mdash310

minus023

minus470

minus234

minus32

86ndash150

1926

1817

911

Tr315

minus018

minus454

minus243

minus34

80ndash

3030

1827

25mdash

mdashmdash

317

minus015

minus463

minus173

minus24

30ndash70

3326

2318

mdashmdash

mdash310

minus006

minus475

minus192

minus255

70ndash150

3430

2016

mdashmdash

mdash298

minus007

minus483

minus184

minus238

ChlchloriteSm

esm


aokaolin





















MgSO4 and K










119901) (119903 = 055lowastlowast 119875 lt 001)



2) for different











0

10

61453746538231245


minus10

minus20

minus30

minus40

Surfa

ce ch

arge

(cm

olck

gminus1)


05

623532423345289212

Surfa

ce ch

arge

(cm

olck

gminus1)

minus10

minus5

minus20

minus15

minus25

minus30

minus35

63657249413425


0

10

minus10

minus20

minus30

minus40

Surfa

ce ch

arge

(cm

olck

gminus1)


6154433732270

10

minus10

minus20

minus30

minus40

minus50

minus60

Surfa

ce ch

arge

(cm

olck

gminus1)


6534541362605

minus10

minus5

minus20

minus15

minus25

minus30

Surfa

ce ch

arge

(cm

olck

gminus1)


5654633226723205

minus10

minus5

minus20

minus15

minus25

minus30

Surfa

ce ch

arge

(cm

olck

gminus1)


544764135292420

10

minus10

minus20

minus30

minus40

Surfa

ce ch

arge

(cm

olck

gminus1)


653453829260

10

minus10

minus20

minus30

minus40

Surfa

ce ch

arge

(cm

olck

gminus1)












4 Conclusion


0and




0in







Acknowledgments


References





























































Journal of












Volume 2014

Advances in









Geophysics








































0




2


0minus pHCaCl

2


0minuspHCaCl

2







0if the soils




0 confirming the



Table3Ch

emicalprop

ertie

softhe

representativ

eprofiles

Soilnu

mber

Depth

(cm)

pHCa

Cl2

pHH2O

pHKC

lΔpH

(KClminusH

2O)

OC

SAR

CCE

EC dSmminus1

CEC

K+Na+

Mg2

+Ca2

+

Fed(

)(125)

cmol

ckgminus

1

1

0ndash25

765

779

760

minus019

034

742137

2985

414

067

2085

65

016

25ndash78

760

776

755

minus021

020

702498

275

263

022

1445

35

015

78ndash110

755

768

750

minus018

023

66

1983

325

334

036

1672

43

014

100ndash

150

770

787

762

minus025

012

772370

1811

313

017

154

52

33

015

2

0ndash20

785

797

780

minus017

018

36

2704

096

215

023

68

48

25

009

20ndash50

790

803

786

minus017

014

37

2755

040

182

022

57

46

22

010

50ndash100

780

795

773

minus022

013

182832

120

154

020

34

43

24

009

100ndash

150

790

794

774

minus020

016

07

2446

093

117

017

1417

23

010

30ndash

3077

579

077

0minus020

037

35

515

428

233

040

7767

28

011

30ndash80

779

793

774

minus019

020

46

5716

700

347

025

121

1032

013

80ndash150

783

797

778

minus021

017

45

5897

548

295

022

108

837

009

4

0ndash20

785

794

780

minus014

033

24

2884

264

176

051

52

47

53

010

20ndash70

793

802

792

minus010

035

30

2885

145

161

018

52

1346

012

70ndash9

578

079

277

5minus017

030

102729

103

144

018

184

1548

011

95ndash150

794

801

790

minus011

043

162798

121

117

015

26

08

43

015

50ndash

4577

578

8772

minus016

035

155820

154

151

021

28

06

65

012

45ndash150

790

804

785

minus019

038

03

5645

037

132

020

04

05

64

013

60ndash

4277

879

771

minus019

029

39

2824

516

275

039

9766

65

009

42ndash88

790

808

786

minus022

033

26

2353

210

195

017

57

48

50

011

88ndash150

789

806

787

minus019

016

48

2536

492

258

023

108

58

45

012

70ndash

3676

878

175

7minus024

037

29

6145

455

243

022

69

51

67

010

36ndash86

780

795

772

minus023

039

21

6041

525

267

024

54

61

64

009

86ndash150

784

798

780

minus018

029

29

6067

496

258

026

7589

45

010

80ndash

3078

079

1776

minus015

024

22

3112

057

168

036

426

43

009

30ndash70

785

789

783

minus006

025

21

3190

080

184

024

38

22

48

006

70ndash150

781

785

778

minus007

026

33

285

066

175

018

627

43

007

OC

organicc

arbo

nSA

Rsodium

adsorptio

nratio

CEC

cationexchange

capacityFe ddith

ionitecitrateb

icarbo

nateC

CEcalcium

carbon

atee

quivalentEC

electric

alcond

uctiv

ity


Table4Re

lativea

bund

ance

ofcla

ymineralandsomee

lectrochem

icalcharacteris

ticso

fthe

soils

studied

Soilnu

mber

Depth

(cm)

Chl

Sme

Pal

IllKa

oSep

Ill-Sme

pH0120575pH

(KClminusH

2O)120575pH

(pH0minusCaC

l 2)120590119901(cmol

ckgminus

1 )120590max(cmol

ckgminus

1 )

1

0ndash25

178

3816

13mdash

lt8

335

minus019

minus465

minus38

minus48

25ndash78

1513

3711

24mdash

mdash320

minus021

minus440

minus273

minus35

78ndash110

2218

357

18mdash

mdash330

minus018

minus425

minus357

minus43

100ndash

150

2022

315

22mdash

mdash320

minus025

minus450

minus292

minus389

2

0ndash20

1616

2518

25mdash

mdash31

5minus017

minus470

minus212

minus295

20ndash50

3722

2412

5mdash

mdash290

minus017

minus500

minus191

minus27

50ndash100

3125

188

8mdash

lt10

300

minus022

minus480

minus143

minus22

100ndash

150

3029

177

9mdash

lt8

280

minus020

minus510

minus154

minus227

30ndash

3010

1533

266

mdashlt10

300

minus020

minus475

minus221

minus32

30ndash80

2121

3020

8mdash

mdash315

minus019

minus469

minus297

minus41

80ndash150

1126

2915

7mdash

lt12

310

minus021

minus446

minus318

minus42

4

0ndash20

238

1635

85

lt5

295

minus014

minus490

minus181

minus34

20ndash70

2014

1424

1810

mdash287

minus010

minus506

minus112

minus255

70ndash9

536

1610

209

9mdash

320

minus017

minus460

minus132

minus22

95ndash150

2720

915

98

lt12

314

minus011

minus480

minus172

minus209

50ndash

4518

1514

337

mdashlt13

311

minus016

minus464

minus159

minus241

45ndash150

2524

2130

mdashmdash

mdash325

minus019

minus465

minus142

minus224

60ndash

4220

1523

307

5mdash

301

minus019

minus477

minus245

minus32

42ndash88

1921

1524

88

lt5

287

minus022

minus503

minus201

minus289

88ndash150

2525

1220

99

mdash290

minus019

minus499

minus243

minus325

70ndash

3628

1432

26mdash

mdashTr

315

minus024

minus438

minus253

minus35

36ndash86

2420

3020

6mdash

mdash310

minus023

minus470

minus234

minus32

86ndash150

1926

1817

911

Tr315

minus018

minus454

minus243

minus34

80ndash

3030

1827

25mdash

mdashmdash

317

minus015

minus463

minus173

minus24

30ndash70

3326

2318

mdashmdash

mdash310

minus006

minus475

minus192

minus255

70ndash150

3430

2016

mdashmdash

mdash298

minus007

minus483

minus184

minus238

ChlchloriteSm

esm


aokaolin





















MgSO4 and K










119901) (119903 = 055lowastlowast 119875 lt 001)



2) for different











0

10

61453746538231245


minus10

minus20

minus30

minus40

Surfa

ce ch

arge

(cm

olck

gminus1)


05

623532423345289212

Surfa

ce ch

arge

(cm

olck

gminus1)

minus10

minus5

minus20

minus15

minus25

minus30

minus35

63657249413425


0

10

minus10

minus20

minus30

minus40

Surfa

ce ch

arge

(cm

olck

gminus1)


6154433732270

10

minus10

minus20

minus30

minus40

minus50

minus60

Surfa

ce ch

arge

(cm

olck

gminus1)


6534541362605

minus10

minus5

minus20

minus15

minus25

minus30

Surfa

ce ch

arge

(cm

olck

gminus1)


5654633226723205

minus10

minus5

minus20

minus15

minus25

minus30

Surfa

ce ch

arge

(cm

olck

gminus1)


544764135292420

10

minus10

minus20

minus30

minus40

Surfa

ce ch

arge

(cm

olck

gminus1)


653453829260

10

minus10

minus20

minus30

minus40

Surfa

ce ch

arge

(cm

olck

gminus1)












4 Conclusion


0and




0in







Acknowledgments


References





























































Journal of












Volume 2014

Advances in









Geophysics















Table3Ch

emicalprop

ertie

softhe

representativ

eprofiles

Soilnu

mber

Depth

(cm)

pHCa

Cl2

pHH2O

pHKC

lΔpH

(KClminusH

2O)

OC

SAR

CCE

EC dSmminus1

CEC

K+Na+

Mg2

+Ca2

+

Fed(

)(125)

cmol

ckgminus

1

1

0ndash25

765

779

760

minus019

034

742137

2985

414

067

2085

65

016

25ndash78

760

776

755

minus021

020

702498

275

263

022

1445

35

015

78ndash110

755

768

750

minus018

023

66

1983

325

334

036

1672

43

014

100ndash

150

770

787

762

minus025

012

772370

1811

313

017

154

52

33

015

2

0ndash20

785

797

780

minus017

018

36

2704

096

215

023

68

48

25

009

20ndash50

790

803

786

minus017

014

37

2755

040

182

022

57

46

22

010

50ndash100

780

795

773

minus022

013

182832

120

154

020

34

43

24

009

100ndash

150

790

794

774

minus020

016

07

2446

093

117

017

1417

23

010

30ndash

3077

579

077

0minus020

037

35

515

428

233

040

7767

28

011

30ndash80

779

793

774

minus019

020

46

5716

700

347

025

121

1032

013

80ndash150

783

797

778

minus021

017

45

5897

548

295

022

108

837

009

4

0ndash20

785

794

780

minus014

033

24

2884

264

176

051

52

47

53

010

20ndash70

793

802

792

minus010

035

30

2885

145

161

018

52

1346

012

70ndash9

578

079

277

5minus017

030

102729

103

144

018

184

1548

011

95ndash150

794

801

790

minus011

043

162798

121

117

015

26

08

43

015

50ndash

4577

578

8772

minus016

035

155820

154

151

021

28

06

65

012

45ndash150

790

804

785

minus019

038

03

5645

037

132

020

04

05

64

013

60ndash

4277

879

771

minus019

029

39

2824

516

275

039

9766

65

009

42ndash88

790

808

786

minus022

033

26

2353

210

195

017

57

48

50

011

88ndash150

789

806

787

minus019

016

48

2536

492

258

023

108

58

45

012

70ndash

3676

878

175

7minus024

037

29

6145

455

243

022

69

51

67

010

36ndash86

780

795

772

minus023

039

21

6041

525

267

024

54

61

64

009

86ndash150

784

798

780

minus018

029

29

6067

496

258

026

7589

45

010

80ndash

3078

079

1776

minus015

024

22

3112

057

168

036

426

43

009

30ndash70

785

789

783

minus006

025

21

3190

080

184

024

38

22

48

006

70ndash150

781

785

778

minus007

026

33

285

066

175

018

627

43

007

OC

organicc

arbo

nSA

Rsodium

adsorptio

nratio

CEC

cationexchange

capacityFe ddith

ionitecitrateb

icarbo

nateC

CEcalcium

carbon

atee

quivalentEC

electric

alcond

uctiv

ity


Table4Re

lativea

bund

ance

ofcla

ymineralandsomee

lectrochem

icalcharacteris

ticso

fthe

soils

studied

Soilnu

mber

Depth

(cm)

Chl

Sme

Pal

IllKa

oSep

Ill-Sme

pH0120575pH

(KClminusH

2O)120575pH

(pH0minusCaC

l 2)120590119901(cmol

ckgminus

1 )120590max(cmol

ckgminus

1 )

1

0ndash25

178

3816

13mdash

lt8

335

minus019

minus465

minus38

minus48

25ndash78

1513

3711

24mdash

mdash320

minus021

minus440

minus273

minus35

78ndash110

2218

357

18mdash

mdash330

minus018

minus425

minus357

minus43

100ndash

150

2022

315

22mdash

mdash320

minus025

minus450

minus292

minus389

2

0ndash20

1616

2518

25mdash

mdash31

5minus017

minus470

minus212

minus295

20ndash50

3722

2412

5mdash

mdash290

minus017

minus500

minus191

minus27

50ndash100

3125

188

8mdash

lt10

300

minus022

minus480

minus143

minus22

100ndash

150

3029

177

9mdash

lt8

280

minus020

minus510

minus154

minus227

30ndash

3010

1533

266

mdashlt10

300

minus020

minus475

minus221

minus32

30ndash80

2121

3020

8mdash

mdash315

minus019

minus469

minus297

minus41

80ndash150

1126

2915

7mdash

lt12

310

minus021

minus446

minus318

minus42

4

0ndash20

238

1635

85

lt5

295

minus014

minus490

minus181

minus34

20ndash70

2014

1424

1810

mdash287

minus010

minus506

minus112

minus255

70ndash9

536

1610

209

9mdash

320

minus017

minus460

minus132

minus22

95ndash150

2720

915

98

lt12

314

minus011

minus480

minus172

minus209

50ndash

4518

1514

337

mdashlt13

311

minus016

minus464

minus159

minus241

45ndash150

2524

2130

mdashmdash

mdash325

minus019

minus465

minus142

minus224

60ndash

4220

1523

307

5mdash

301

minus019

minus477

minus245

minus32

42ndash88

1921

1524

88

lt5

287

minus022

minus503

minus201

minus289

88ndash150

2525

1220

99

mdash290

minus019

minus499

minus243

minus325

70ndash

3628

1432

26mdash

mdashTr

315

minus024

minus438

minus253

minus35

36ndash86

2420

3020

6mdash

mdash310

minus023

minus470

minus234

minus32

86ndash150

1926

1817

911

Tr315

minus018

minus454

minus243

minus34

80ndash

3030

1827

25mdash

mdashmdash

317

minus015

minus463

minus173

minus24

30ndash70

3326

2318

mdashmdash

mdash310

minus006

minus475

minus192

minus255

70ndash150

3430

2016

mdashmdash

mdash298

minus007

minus483

minus184

minus238

ChlchloriteSm

esm


aokaolin





















MgSO4 and K










119901) (119903 = 055lowastlowast 119875 lt 001)



2) for different











0

10

61453746538231245


minus10

minus20

minus30

minus40

Surfa

ce ch

arge

(cm

olck

gminus1)


05

623532423345289212

Surfa

ce ch

arge

(cm

olck

gminus1)

minus10

minus5

minus20

minus15

minus25

minus30

minus35

63657249413425


0

10

minus10

minus20

minus30

minus40

Surfa

ce ch

arge

(cm

olck

gminus1)


6154433732270

10

minus10

minus20

minus30

minus40

minus50

minus60

Surfa

ce ch

arge

(cm

olck

gminus1)


6534541362605

minus10

minus5

minus20

minus15

minus25

minus30

Surfa

ce ch

arge

(cm

olck

gminus1)


5654633226723205

minus10

minus5

minus20

minus15

minus25

minus30

Surfa

ce ch

arge

(cm

olck

gminus1)


544764135292420

10

minus10

minus20

minus30

minus40

Surfa

ce ch

arge

(cm

olck

gminus1)


653453829260

10

minus10

minus20

minus30

minus40

Surfa

ce ch

arge

(cm

olck

gminus1)












4 Conclusion


0and




0in







Acknowledgments


References





























































Journal of












Volume 2014

Advances in









Geophysics















Table4Re

lativea

bund

ance

ofcla

ymineralandsomee

lectrochem

icalcharacteris

ticso

fthe

soils

studied

Soilnu

mber

Depth

(cm)

Chl

Sme

Pal

IllKa

oSep

Ill-Sme

pH0120575pH

(KClminusH

2O)120575pH

(pH0minusCaC

l 2)120590119901(cmol

ckgminus

1 )120590max(cmol

ckgminus

1 )

1

0ndash25

178

3816

13mdash

lt8

335

minus019

minus465

minus38

minus48

25ndash78

1513

3711

24mdash

mdash320

minus021

minus440

minus273

minus35

78ndash110

2218

357

18mdash

mdash330

minus018

minus425

minus357

minus43

100ndash

150

2022

315

22mdash

mdash320

minus025

minus450

minus292

minus389

2

0ndash20

1616

2518

25mdash

mdash31

5minus017

minus470

minus212

minus295

20ndash50

3722

2412

5mdash

mdash290

minus017

minus500

minus191

minus27

50ndash100

3125

188

8mdash

lt10

300

minus022

minus480

minus143

minus22

100ndash

150

3029

177

9mdash

lt8

280

minus020

minus510

minus154

minus227

30ndash

3010

1533

266

mdashlt10

300

minus020

minus475

minus221

minus32

30ndash80

2121

3020

8mdash

mdash315

minus019

minus469

minus297

minus41

80ndash150

1126

2915

7mdash

lt12

310

minus021

minus446

minus318

minus42

4

0ndash20

238

1635

85

lt5

295

minus014

minus490

minus181

minus34

20ndash70

2014

1424

1810

mdash287

minus010

minus506

minus112

minus255

70ndash9

536

1610

209

9mdash

320

minus017

minus460

minus132

minus22

95ndash150

2720

915

98

lt12

314

minus011

minus480

minus172

minus209

50ndash

4518

1514

337

mdashlt13

311

minus016

minus464

minus159

minus241

45ndash150

2524

2130

mdashmdash

mdash325

minus019

minus465

minus142

minus224

60ndash

4220

1523

307

5mdash

301

minus019

minus477

minus245

minus32

42ndash88

1921

1524

88

lt5

287

minus022

minus503

minus201

minus289

88ndash150

2525

1220

99

mdash290

minus019

minus499

minus243

minus325

70ndash

3628

1432

26mdash

mdashTr

315

minus024

minus438

minus253

minus35

36ndash86

2420

3020

6mdash

mdash310

minus023

minus470

minus234

minus32

86ndash150

1926

1817

911

Tr315

minus018

minus454

minus243

minus34

80ndash

3030

1827

25mdash

mdashmdash

317

minus015

minus463

minus173

minus24

30ndash70

3326

2318

mdashmdash

mdash310

minus006

minus475

minus192

minus255

70ndash150

3430

2016

mdashmdash

mdash298

minus007

minus483

minus184

minus238

ChlchloriteSm

esm


aokaolin





















MgSO4 and K










119901) (119903 = 055lowastlowast 119875 lt 001)



2) for different











0

10

61453746538231245


minus10

minus20

minus30

minus40

Surfa

ce ch

arge

(cm

olck

gminus1)


05

623532423345289212

Surfa

ce ch

arge

(cm

olck

gminus1)

minus10

minus5

minus20

minus15

minus25

minus30

minus35

63657249413425


0

10

minus10

minus20

minus30

minus40

Surfa

ce ch

arge

(cm

olck

gminus1)


6154433732270

10

minus10

minus20

minus30

minus40

minus50

minus60

Surfa

ce ch

arge

(cm

olck

gminus1)


6534541362605

minus10

minus5

minus20

minus15

minus25

minus30

Surfa

ce ch

arge

(cm

olck

gminus1)


5654633226723205

minus10

minus5

minus20

minus15

minus25

minus30

Surfa

ce ch

arge

(cm

olck

gminus1)


544764135292420

10

minus10

minus20

minus30

minus40

Surfa

ce ch

arge

(cm

olck

gminus1)


653453829260

10

minus10

minus20

minus30

minus40

Surfa

ce ch

arge

(cm

olck

gminus1)












4 Conclusion


0and




0in







Acknowledgments


References





























































Journal of












Volume 2014

Advances in









Geophysics

































MgSO4 and K










119901) (119903 = 055lowastlowast 119875 lt 001)



2) for different











0

10

61453746538231245


minus10

minus20

minus30

minus40

Surfa

ce ch

arge

(cm

olck

gminus1)


05

623532423345289212

Surfa

ce ch

arge

(cm

olck

gminus1)

minus10

minus5

minus20

minus15

minus25

minus30

minus35

63657249413425


0

10

minus10

minus20

minus30

minus40

Surfa

ce ch

arge

(cm

olck

gminus1)


6154433732270

10

minus10

minus20

minus30

minus40

minus50

minus60

Surfa

ce ch

arge

(cm

olck

gminus1)


6534541362605

minus10

minus5

minus20

minus15

minus25

minus30

Surfa

ce ch

arge

(cm

olck

gminus1)


5654633226723205

minus10

minus5

minus20

minus15

minus25

minus30

Surfa

ce ch

arge

(cm

olck

gminus1)


544764135292420

10

minus10

minus20

minus30

minus40

Surfa

ce ch

arge

(cm

olck

gminus1)


653453829260

10

minus10

minus20

minus30

minus40

Surfa

ce ch

arge

(cm

olck

gminus1)












4 Conclusion


0and




0in







Acknowledgments


References





























































Journal of












Volume 2014

Advances in









Geophysics

















0

10

61453746538231245


minus10

minus20

minus30

minus40

Surfa

ce ch

arge

(cm

olck

gminus1)


05

623532423345289212

Surfa

ce ch

arge

(cm

olck

gminus1)

minus10

minus5

minus20

minus15

minus25

minus30

minus35

63657249413425


0

10

minus10

minus20

minus30

minus40

Surfa

ce ch

arge

(cm

olck

gminus1)


6154433732270

10

minus10

minus20

minus30

minus40

minus50

minus60

Surfa

ce ch

arge

(cm

olck

gminus1)


6534541362605

minus10

minus5

minus20

minus15

minus25

minus30

Surfa

ce ch

arge

(cm

olck

gminus1)


5654633226723205

minus10

minus5

minus20

minus15

minus25

minus30

Surfa

ce ch

arge

(cm

olck

gminus1)


544764135292420

10

minus10

minus20

minus30

minus40

Surfa

ce ch

arge

(cm

olck

gminus1)


653453829260

10

minus10

minus20

minus30

minus40

Surfa

ce ch

arge

(cm

olck

gminus1)












4 Conclusion


0and




0in







Acknowledgments


References





























































Journal of












Volume 2014

Advances in









Geophysics

















4 Conclusion


0and




0in







Acknowledgments


References





























































Journal of












Volume 2014

Advances in









Geophysics






















































Journal of












Volume 2014

Advances in









Geophysics














Research Article Physicochemical Properties and Surface...

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