characterization and classification of soils of abobo area, western

Research ArticleCharacterization and Classification of Soils ofAbobo Area Western Ethiopia

Teshome Yitbarek1 Shelem Beyene2 and Kibebew Kibret3

1Department of Natural Resource Management College of Natural Resource Wolkite University PO Box 07 Wolkite Ethiopia2Department of Plant and Horticultural Science College of Agriculture Hawassa University PO Box 05 Hawassa Ethiopia3School of Natural Resources and Environmental Science College of Agriculture and Environmental Science Haramaya UniversityPO Box 138 Dire Dawa Ethiopia

Correspondence should be addressed to Teshome Yitbarek teshalm7gmailcom

Received 31 August 2016 Accepted 16 November 2016

Academic Editor Rafael Clemente

Copyright copy 2016 Teshome Yitbarek et al This is an open access article distributed under the Creative Commons AttributionLicense which permits unrestricted use distribution and reproduction in any medium provided the original work is properlycited

Knowledge of the kinds and properties of soils is critical for making decisions with respect to crop production and other land usetypes A field survey and soil morphological description and laboratory analysis were carried out to describe characterize andclassify the soils of Abobo area western Ethiopia Seven representative pedons (A-1 to A-7) were opened and described across thestudy areaThe results revealed variation in morphological physical and chemical properties of the soilsThe soils are clay loam toclayey in texture with bulk density values ranging from 112 to 132 g cmminus3 and basic infiltration rate varying from slow to moderate(04 to 33 cmhrminus1) They were moderately acidic to neutral in pH (55 to 71) and had very low to medium organic carbon (OC)(027 to 298) Four soil types Haplic Cambisols Vertic Luvisols Mollic Leptosols and Mollic Vertisols were identified in thearea based on World Reference Base Generally the properties of the soils differed along the transect indicating their variation inproductive potential and management requirements for specific agricultural use

1 Introduction

Knowledge of the kinds and properties of soils is criti-cal for decisions making with respect to crop productionand other land use types It is through precise measurementand full understanding of the nature and properties of soilsas well as proper management of the nutrient and moisturerequirements that one can maximize crop production to theallowable potential limits [1] In order to evaluate the qualityof our natural resources and their potential to produce foodfodder fiber and fuel for the present and future generationsdetailed information on soil properties is required

Assessment of soil for land use planning is increasinglyimportant due to increasing competition for land amongmany land uses and the transition from subsistence tomarketbased farming in many countries [2] High quality soil clas-sification therefore is the basis for efficient land suitabilityevaluation planning and management Soil classification isimportant in identifying the most appropriate use of soil

estimating production extrapolating knowledge gained atone location to other often relatively little known locationsand providing a basis for future research needs [3] Soil char-acterization is required to classify soil and determine chem-ical and physical properties not visible in field examination[4]

Since the early works of Dokuchaev there has beenbelief in the dependence of soil properties on soil processeswhich depend in turn on soil-forming factors The five soil-forming factors can combine in almost endless ways to giverise to many kinds of soil individuals It is impossible toremember their names let alone their properties hencethere is need to organize soils information by classificationsystems [5] Landscape position influences runoff drainageerosion and soil depth and thereby soil formation anddevelopment Different soil properties such as pH OC sandand clay contents and distribution are highly correlated withlandscape positions [6 7]

Hindawi Publishing CorporationApplied and Environmental Soil ScienceVolume 2016 Article ID 4708235 16 pageshttpdxdoiorg10115520164708235

2 Applied and Environmental Soil Science

Agriculture has been the mainstay of Ethiopian economyfor centuries and will remain the same for the coming manyyears [8] However reliable soils data which are the pre-requisite for the design of appropriate land use systems andsoilmanagement practices are not adequately availableMostof the studies undertaken so far were localized mostly toareas close to major transportation networks and some of theavailable data are not currently used as they are 20ndash30 yearsold [9]

All the previous studies conducted in Gambella thepresent study area were at small scale [10 11] National andregional small-scale studies seem to be inadequate in provid-ing basic soil data that can help to manage soils according tolocal variability [12] This study was therefore initiated andcarried out in Abobo area of Gambella region to characterizeand classify the soils of the area in detail

2 Materials and Methods

21 Description of the Study Area The study area Abobodistrict is located at 42 km south of Gambella town andabout 808 km west of Addis Ababa It lies between 07∘5010158404710158401015840to 08∘0110158405910158401015840N and 34∘2810158405910158401015840 to 34∘3410158403710158401015840E with altituderanging from 446 to 490 meters above sea level (masl) andslope from flat (02ndash05) to gently sloping (2ndash5)

The climate of the region is influenced by the tropicalmonsoon which is characterized by high rainfall in the wetperiod from May to October and little rainfall during thedry period from November to April [11] The average annualrainfall is 9555mm whereas the mean minimum and meanmaximum monthly temperatures range from 162 to 212∘Cand 321 to 382∘C respectively The region is drained by anumber of perennial rivers including Baro Alwero GilloAkobo and their tributaries

The geology of Abobo is characterized by undifferenti-ated Pleistocene Holocene deposits Granite gneisses schistsandstone and basalt are the rock types existing in the region[13] The major soils of Abobo District include Dystric andEutric Plinthosols Dystric and Chromic Cambisols EutricVertisols and Planosols where Cambisols occur at the upperslope north of Abobo while Plinthosols and Vertisols exist atthe middle and lower slopes respectively [11]

The Abobo district encompasses forest land woodlandshrub land grassland and cultivated land occupying 14308675227 5793 62997 and 19854 hectares (ha) respectively[14] The forest cover is continuously declining due to set-tlement and agricultural expansion The major crops grownby farmers include maize (Zea mays L) sorghum (Sorghumbicolor) groundnut (Arachis hypogaea) and sesame (Sesa-mum aestivum) whereas cotton (Gossypium sp) and rice(Oryza sativa L) are cultivated by state farms and investorsoperating in and around the study area

22 FieldWork Prior to the start of the field soil descriptionsthe boundaries of the kebeles (the smallest administrativeunit) along the transect were delineated using digital mapof Gambella region and the soils within each kebele werethoroughly examined and differentiated based on observablesite and soil characteristics such as slope soil depth and

texture following free survey method [15] The approach wasto traverse the landscape along selected transects (north tosouth) by auger inspection at enough points to identify theexisting soils type and their boundaries

The study area was categorized into seven soil units afterinspecting 189 auger samples A representative soil pedon15 times 2m was opened in each identified soil unit and de-scribed in situ following theGuidelines for Field Soil Descrip-tion [16] General site information and soil description wererecorded and samples were collected from every identifiedhorizon Core samples were collected at different pointsacross each horizon Infiltration rates were measured intriplicate in each identified soil unit using double ringinfiltrometer [17]The rate wasmeasured by observing the fallof water within concentric cylinders (28 and 53 cm diameterwith 24 cmheight) driven 10 cmvertically into the soil surfacelayer

Based on the morphological properties and the labora-tory analysis the soils of the study areawere classified accord-ing to WRB [18] and Soil Taxonomy [19]

23 Laboratory Analysis The samples collected from identi-fied horizons of all pedons were air-dried and ground to passthrough 2mm sieve For the determinations of total N andOC a 05mm sieve was used Analyses of the physicochemi-cal properties were carried out following standard laboratoryprocedures

Bulk and particle densities were determined by core sam-pling [20] and pycnometer [21] methods respectively Parti-cle size distribution was determined by Bouyoucos hydrom-eter method [22] Total porosity was computed from themeasurements of soil dry bulk density (120588119887) and soil particledensity (120588119901) as

Porosity = 1 minus (120588119887120588119901) (1)

Water retention at field capacity (FC) and permanent wiltingpoint (PWP) was measured by employing pressure plateextraction methods [23] and available water content (AWC)was computed by subtracting values of permanent wiltingpoint from that of field capacity

Soil pH and electrical conductivity were measured usinga 1 25 soil to water ratio [24] whereas OC was determinedby wet digestion method [25] Total N was determined byKjeldahl wet digestion and distillation method [26] availableP by the modified Olsen method [27] and available K usingsodium acetate extractant [28] The CEC and exchangeablebases were extracted by 1M ammonium acetate (pH 7)method [29] In the extract exchangeable Ca and Mg weredetermined by atomic absorption spectrophotometer (AAS)and exchangeable K and Na by flame photometer Availablemicronutrients (Fe Mn Zn and Cu) of the soil were extract-ed by diethylene triamine pentaacetic acid (DTPA) methodas described in Tan [21] and determined using AAS Calciumcarbonate and gypsum contents were determined followingacid neutralization method [30] and Nelson procedure [31]respectively

Applied and Environmental Soil Science 3

Table 1 Site characteristics and land usecover of the study area

Pedons Coordinates Altitude (masl) Land form1 SP2 PM3 Slope () Land usecoverLatitude Longitude

A-1 08∘0110158403510158401015840 034∘3310158404210158401015840 490 GS UP B 2 Maize farmA-2 07∘5910158405410158401015840 034∘3310158402510158401015840 479 VGS MS B 1 Sesame farmA-3 07∘5510158403410158401015840 034∘3310158403610158401015840 469 VGS MS B 1 Cotton farmA-4 07∘5810158402510158401015840 034∘3310158401810158401015840 468 VGS MS B 1 Fallow landA-5 07∘5610158403610158401015840 034∘3210158402510158401015840 462 NF MS A 05 Maize farmA-6 07∘5310158404510158401015840 034∘2910158405410158401015840 455 NF MS B 05 Maize farmA-7 07∘4810158403410158401015840 034∘3110158404010158401015840 446 F LS A 02 Forest land1F = flat NF = nearly flat VGS = very gently sloping GS = gently sloping 2SP = slope position MS = middle slope UP = upper slope LS = lower slope 2PM= parent materials B = basalt A = alluvium

The following parameters were computed from the resultof the chemical analysis

(i) Organicmatter ()= Organic carbon (OC) lowast 1724

(ii) Carbonnitrogen ratio

= OCTotal N

(iii) CEC of clay (cmolckg)= [ CEC of soil

percentage of clay] lowast 100

Exchangeable sodium percentage ()= [Exchangeable Na

CEC] lowast 100

Calciummagnisium ratio

= Exchangeable Caexchangeable Mg

(iv) Percent base saturation ()= [Exchangeable Ca +Mg + K + Na

CEC]

lowast 100

(2)

24 Statistical Analysis and Mapping General Linear Model(GLM) procedure [32] version 92 was employed to analyzethe correlation among soil parameters The soils map of thestudy area was prepared by employing ArcGIS 93

3 Results and Discussion

31 Characteristics of the Study Area The site characteristicsof the pedons indicated that the study area was situated onlevel to gentle sloping (Table 1) and the pedons representeddifferent physiographic position PedonAbobo- (A-) 1 (upperslope) Pedons A-2 A-3 A-4 A-5 and A-6 (middle slope)and Pedon A-7 lower slope of the terrain The pedons werealso representatives of different land usecover maize farm(A-1 A-5 and A-6) sesame farm (A-2) cotton farm (A-3)fallow land (A-4) and forest land (A-7) All the pedons were

well drained except Pedon A-7 which was on lower slopepositions and imperfectly drained

In the upper andmiddle slope classes slight sheet erosionwas observed whereas deposition was prevalent in the lowerslope area Furthermore the existing land usecover at thearea has also contributed to the erosion process Cultivatedland which is highly exposed to rainfall impact was inthe upper slope soils of the terrain Removal of surface soilfrom this land use affected the soil profile development incomparison with the middle and lower slope soils Erosion ofmaterials from O or A horizons of upslope and their deposi-tion on lower slopes are common phenomena contributingto a textural differentiation with finer-textured soils in thelower landscape positions [33] Due to repeated deposition ofsoluble materials the lower slope would have relatively higherexchangeable bases content in comparison with middle andupper slopes

32 Morphological Properties of the Soils The pedons exhib-ited differences in sequence of horizons whereas Pedon A-6 consisted of only one genetic soil horizon (Ap) the othersconsisted of 3-4 horizons (Table 2) The pedon (A-1) at theupper part of the site had relatively shallower (18 cm) surfacehorizon compared to that of others due to removal of surfacematerials This is attributed to slope which contributes togreater translocation of surfacematerials down slope throughsurface erosion and movement of soil [34] Variation in soildepth particle size distribution structure and color couldalso be due to the difference in parent material [35]

The color of surface horizons varied from brown (75YR44) to dark yellow brown (10YR 44) and dark brown (75YR34) to dark yellowish brown (10YR 34) when they were dryand moist respectively whereas the color of the subsurfacehorizons varied from reddish brown (25YR 44) to gray(25Y 61) and reddish brown (25YR 43) to gray (25Y 51)at respective moisture levels (Table 2) The color differencesbetween surface and subsurface layers reflect biological pro-cesses notably those influenced by the soil organic matter Inline with this many authors reported that the surface hori-zons have darker color than the corresponding subsurfacehorizons as a result of relatively higher soil OM contents[7 36] PedonsA-1 A-2A-3 andA-4had bright-colored (redreddish brown and yellowish red) subsoils which might be


Table2Selected

morph

ologicalprop

ertie

softhe

pedo

ns

Pedo

nHorizon

Depth

(cm)

Boun

dary1

Color

Texture

(Feelm

etho

d)2

Structure3

Con

sistency4

Coarsefragm

ent()

Dry

Moist

A-1

Ap0ndash

18GS

10YR

36

10YR

33

CLMOV

MG

RSH

AFR

STSPL

mdashBw

118ndash25

GS

25Y

R46

25Y

R44

CLMOV

MA

BSH

AFR

STSPL

mdashBw

225ndash35

GS

25Y

R48

25Y

R46

CMOFMA

BSH

AFR

STP

Lmdash

CB35ndash110

mdash25Y

R46

25Y

R46

CMOFMA

BSH

AFR

STP

L47

A-2

A0ndash

18GS

10YR

43

10YR

32

CLMOFMG

RSH

RFR

STPL

mdashAd

18ndash27

CS10YR

43

10YR

32

CLMOFMA

BSH

AFR

STP

Lmdash

Bt1

27ndash37

CS25Y

R44

25Y

R43

CMOM

EAB

SHAFR

STP

Lmdash

Bt2

37ndash50

GS

25Y

R46

25Y

R45

CMOM

EAB

SHAFR

STP

Lmdash

BC50ndash80

mdash25Y

R46

25Y

R45

CMOM

EAB

SHAFR

STP

L21

A-3

Ap0ndash

22CS

75YR

33

75YR

33

CLMOFMG

RSH

AFR

STP

Lmdash

A22ndash33

CS75

YR33

75YR

32

CMOM

EAB

HAFR

VSTVPL

mdashBt1

33ndash4

5GS

5YR46

5YR44

CMOM

EAB

HAFR

VSTVPL

mdashBt2

45ndash6

3GS

5YR44

25Y

R43

CMOM

EAB

HAFR

VSTVPL

mdashBC

63ndash85

mdash5Y

R46

5YR44

CMOM

EAB

HAFR

VSTVPL

19

A-4

Ap0ndash

10CS

10YR

36

10YR

33

CLWE

FIG

RSH

AFR

STP

Lmdash

A10ndash19

CS10YR

34

10YR

33

CSTFMSB

VHAFISTP

Lmdash

Bt1

19ndash37

GS

75YR

44

75YR

33

CSTFMA

BVHAFISTP

Lmdash

Bt2

37ndash75

GS

5YR46

5YR34

CSTFMA

BHAFISTP

Lmdash

BC75ndash85

mdash5Y

R46

5YR44

CSTFMA

BSH

AFR

TSP

L23

A-5

Ap0ndash

17GS

10YR

37

10YR

31

CMOM

CAB

HAFR

STP

Lmdash

A17ndash55

GS

10YR

52

10YR

32

CSTC

OA

BVHAFISTP

Lmdash

Bss1

55ndash116

GS

25Y

52

25Y

42

CSTC

OA

BVHAV

FISTPL

mdashBC

ss2

116ndash

150

mdash10YR

52

10YR

32

CVS

TCO

AB

VHAV

FISTPL

mdashA-

6Ap

0ndash20

mdash10YR

43

10YR

32

LMOFMG

RSH

AFR

STP

Lmdash

A-7

A0ndash

29CS

10YR

32

10YR

21

CMOFMA

BSH

AFR

STP

Lmdash

Bss1

29ndash4

8GS

10YR

44

10YR

34

CSTV

CAB

EHAE

FIV

STV

PLmdash

Bss2

48ndash105

GS

10YR

36

10YR

32

CSTE

CAB

EHAE

FIV

STV

PLmdash

BCss

105ndash150+

mdash25Y

61

25Y

51

CSTE

CPR

EHAE

FIV

STV

PLmdash

1CS

=cle

arandsm

oothG

S=gradualand

smoo

th

2CL

=cla

yloam

C=cla

y3WE=weakST

=str

ongMO

=mod

erateVS

T=very

stron

gFI

=fin

eFM

=fin

eandmediumV

M=very

fineto

mediumM

C=medium

andcoarseM

E=mediumC

O=coarseV

C=very

coarseE

C=

extre

mely

coarseG

R=granularSB=subang

ular

blockyA

B=angularb

lockyPR

=prism

atic

4SH

A=slightly

hardV

HA=very

hardH

A=hardE

HA=extre

mely

hardST=stickySST=slightly

stickyVS

T=very

stickyPL

=plasticSPL

=slightly

plasticV

PL=very

plasticFR=friableFI

=firmE

FI=extre

mely

firm


Table 3 Particle size distribution and textural classes of soils of Abobo area

Pedon Horizon Depth (cm) Particle size distribution () Textural classSand Silt Clay

A-1

Ap 0ndash18 37 28 35 Clay loamBw1 18ndash25 33 31 36 Clay loamBw2 25ndash35 30 33 37 Clay loamCB 35ndash110 35 30 35 Clay loam

A-2

A 0ndash18 20 29 51 ClayAd 18ndash27 20 27 53 ClayBt1 27ndash37 17 26 57 ClayBt2 37ndash50 23 12 65 ClayBC 50ndash80 26 21 53 Clay

A-3

Ap 0ndash22 26 17 57 ClayA 22ndash33 28 20 52 ClayBt1 33ndash45 25 14 61 ClayBt2 45ndash63 24 14 62 ClayBC 63ndash85 36 14 50 Clay

A-4


A-5

Ap 0ndash17 21 24 55 ClayA 17ndash55 23 18 59 ClayBss1 55ndash116 27 14 59 ClayBCss2 116ndash150 24 15 61 Clay

A-6 Ap 0ndash20 35 32 33 Clay loam

A-7

A 0ndash29 35 18 47 ClayBss1 29ndash48 31 15 54 ClayBss2 48ndash105 27 8 65 ClayBCss 105ndash150+ 21 11 68 Clay

due to oxidized Fe indicating good drainage conditions of thesoils

The surface horizons had granular and angular blockystructures with varied grade and size whereas the subsurfacehorizons had moderate to very strong and fine to extremelycoarse angular blocky and prismatic structures (Table 2)Generally the size of the peds increased with depth andpeds get larger and more block-like as was also reported byprevious study [37] Many of the peds were held together bycoatings (cutans) of material that had been translocated intothis horizon Organic matter and microbial exudates serve toform and temporally stabilize the granular aggregates [38]although physical disruption of surface horizons reduces themicrobial activity and aggregate stability as the stabilizingorganic compounds are decomposed

The dry consistence of the surface soil was slightly hardexcept Pedon A-5 which had hard consistence (Table 2)whereas the moist and wet consistencies were friable andstickyplastic respectively Likewise the subsurface horizonshad slightly hard to extremely hard (dry) friable to extreme-ly firm (moist) and slightly stickyplastic to very stickyvery plastic (wet) consistence Generally friable consistence

indicates the composition of different size of particles thepresence of organic materials and microbiological activitiesin the soil It was pointed out that the friable consistenceobserved in the surface soils of the pedons could be attributedto the higher soil OM contents of the layers [7] The friableconsistency of the soils indicates that the soils are workable atappropriate moisture content [36]

33 Physical Properties

331 Particle Size Distribution The particle size determina-tion showed that the soils of the study area are clay textureexcept for the upper (A-1) andmiddle (A-6) slopes which areclay loam (Table 3)The clay content varied from 33 to 59 inthe surface horizons and generally increased with depth

The textural differentiation might be caused by an illuvialaccumulation of clay predominant pedogenetic formation ofclay in the subsoil destruction of clay in the surface horizonselective surface erosion of clay upwardmovement of coarserparticles due to swelling and shrinking biological activityand a combination of two ormore of these different processes[18]


Table 4 Bulk density (120588119887) particle density (120588119901) total porosity (TP) water content and available water content (AWC) of soils of Abobo area

Pedon Horizon Depth (cm) 120588119887 (g cmminus3) 120588119901 (g cmminus3) TP ()Water content (volume

) AWC(volume )

FC PWP

A-1

Ap 0ndash18 120 242 5041 42 25 17Bw1 18ndash25 122 242 4959 39 23 16Bw2 25ndash35 132 252 4762 40 26 14CB 35ndash110 mdash mdash mdash mdash mdash mdash

A-2

A 0ndash18 121 248 5121 40 24 16Ad 18ndash27 127 248 4879 39 26 13Bt1 27ndash37 129 251 4861 40 26 16Bt2 37ndash50 129 250 4840 38 23 15BC 50ndash80 mdash mdash mdash mdash mdash mdash

A-3

Ap 0ndash22 120 244 5082 47 29 18A 22ndash33 121 244 4959 43 28 15Bt1 33ndash45 123 243 4938 41 24 17Bt2 45ndash63 125 241 4813 41 23 18BC 63ndash85 mdash mdash mdash mdash mdash mdash

A-4


A-5

Ap 0ndash17 120 250 5200 42 27 15A 17ndash55 124 244 4918 44 31 13Bss1 55ndash116 125 238 4748 41 29 12BCss2 116ndash150 mdash mdash mdash mdash mdash mdash

A-6 Ap 0ndash20 120 253 5257 35 19 16

A-7

A 0ndash29 112 237 5274 39 23 16Bss1 29ndash48 121 231 4784 45 31 14Bss2 48ndash105 125 232 4612 49 34 15BCss 105ndash150+ mdash mdash mdash mdash mdash mdash

mdash not determined FC field capacity PWP permanent wilting point

In the surface horizons of the pedons silt and sandcontents varied from 17 to 32 and 20 to 37 respectivelywhereas their respective values varied from 8 to 33 and 15 to36 in the subsurface horizons Negative and significant (119903 =minus078 119901 lt 0001) correlation was observed between clay andsand indicating that removal of clay results in accumulationof sand (Table 10)

332 Bulk Particle Density Total Porosity and Soil WaterRetention The bulk and particle density values of the surfacehorizons ranged from 112 to 121 and 237 to 253 g cmminus3respectively (Table 4) Relatively higher (121 g cmminus3) surfacehorizons bulk density was recorded for the cultivated landwhich could be attributed to compaction created due to cul-tivation An increase in soil bulk density by 2142 wasobserved due to deforestation and subsequent cultivation[39]

The total pore space in the surface layer ranged from 52to 53 (Table 4) The values were within the range (40 to 60)of clay texture total porosity [40] and showed decreasingtrendwith soil depthThis could be related to the distributionof organic matter content and natural compaction of thesubsurface soils by the load of surface soils [41] As the soilOM contents decreased the soils would be less aggregatedand the bulk density would be increased As a result thetotal porosity would be decreased The correlation analysisrevealed highly negative and significant (119903 = minus092 119901 lt0001) relationship between bulk density and total porosity(Table 10)

Following the general relationship of soil bulk density toroot growth the root-restricting bulk densities for clay aregreater than 147 g cmminus3 [42] and for clay loam greater than175 g cmminus3 [43] Thus the soils of the study area were notcompacted to the extent of restricting root growth


Table 5 Infiltration characteristics of soils of Abobo area

Nearby pedon Coordinates Basic infiltration rate (cmhrminus1) CategoriesLatitude Longitude

A-1 08∘01101584035110158401015840 034∘33101584042010158401015840 33 ModerateA-2 07∘59101584054710158401015840 034∘33101584025910158401015840 11 Moderately slowA-3 07∘54101584002110158401015840 034∘33101584031810158401015840 20 ModerateA-4 07∘57101584005010158401015840 034∘33101584010010158401015840 17 Moderately slowA-5 07∘54101584036910158401015840 034∘32101584012910158401015840 05 Moderately slowA-6 07∘52101584049010158401015840 034∘29101584054910158401015840 21 ModerateA-7 07∘51101584023510158401015840 034∘29101584002710158401015840 04 Slow

The soil water content at field capacity (33 kPa) variedfrom 35 to 49 for clay loam and clay textural classesrespectively (Table 4) whereas at permanent wilting point itvaried from 19 to 34 for the same soil textural classes Theavailable water content ranged from 12 to 18 and the valueswere influenced by organic matter and clay contents withinthe horizons

333 Infiltration Basic infiltration rate varied from04 (clay-ey soil of A-7) to 33 cmhrminus1 (clay loam texture of Pedon A-1) showing that the relatively higher sand content in PedonA-1 contributed to the highest infiltration rate whereas theexpansive clay decreased the infiltration rate in case ofPedon A-7 (Table 5) Infiltration rates were initially high inall pedons perhaps due to the large suction gradients andprogressively approached final steady state The decrease ofinfiltrability from an initially high rate can in some casesresult from gradual deterioration of soil structure and thepartial sealing of the profile by the formation of a surface crust[44] It can also result from the detachment and migration ofpore-blocking particles from swelling of clay as well as fromentrapment of air bubbles or the bulk compression of the airoriginally present in the soil if it is prevented from escapingduring its displacement by incoming water

The soils of the study area could be categorized underslowmoderately slow andmoderate infiltration rate [17]Theauthor concluded that soils having average infiltration ratesless than 01 cmhrminus1 are usually considered nonirrigable forcrops other than rice indicating that the soils of the area aresuitable for irrigation

34 Chemical Properties

341 Soil pH Electric Conductivity Calcium Carbonate andGypsum Contents The results revealed that the pH (H2O) ofthe surface soil ranged from 55 to 71 whereas the subsurfacepH values were between 57 and 67 (Table 6) indicatingthat the soils are moderately acidic to neutral [45] In therange of pH 55 to 7 hydroxyl aluminum polymers predom-inate among acids soil components exchangeable acidity isvirtually absent and only none exchangeable and titratableacidity are present in measurable quantities [46] Althoughpotential acidity depends on the equilibrium pH of the soilsuspension [47] exchangeable aluminum normally occurs insignificant amounts only at soil pH values less than about 55

Considering the optimum pH for many plant species to be55 to 68 [48] and absence of free exchangeable Al in thisrange the pH of the soils in study area could be consideredas suitable for most crop production

The pH (KCl) values ranged from 47 to 64 and 49 to 59for surface and subsurface horizons respectively (Table 6)The pHmeasurements in KCl were lowered by 05 to 13 unitscompared to pH measurements in H2O Increasing the neu-tral salt concentration to 01 or 1M can lower the measuredsoil pH as much as 05 to 15 units compared to in distilledwater suspensions [46] because H and Al cations on ornear soil colloid surfaces can be displaced by exchange withsoluble cations If a higher reading is obtained in salt solutionthan in water this almost invariably indicates poor nutrientavailability and the likelihood of strong phosphate fixation[17]

Electrical conductivity (EC) values of the pedon variedfrom 005 to 024 dSmminus2 and in accordance with the ECrating the soils of the study area were nonsaline [49] Sim-ilarly the calcium carbonate (CaCO3) content within thepedons varied from 013 to 039 whereas the gypsum(CaSO4sdot2H2O) content was trace throughout the soil profilesThus the soils were low in both calcium carbonate [17] andgypsum contents [50] The EC and CaCO3 contents showedirregular pattern in most of the pedons with increasingdepth indicating low degree of leaching process in the areaHowever Pedons A-5 and A-7 showed increasing trained inCaCO3 content with depth

342 Organic Carbon Total Nitrogen Carbon to NitrogenRatio Available Phosphorus and Potassium The organic car-bon (OC) content ranged from 132 to 298 in the surfacelayers of all pedons and could be categorized under low tomedium [51] The values decreased with increasing depth inall pedons (Table 7) Generally the low to medium content ofsoil OC is attributed to the warmer climate which enhancesrapid rate of mineralization [41] Relatively higher OC(298) for surface layers was recorded in fallow land (PedonA-4) while the lowest (132) was recorded in cultivated cot-ton state farm (PedonA-3)The difference could be attributedto the rapid decomposition and mineralization of organicmatter under cultivation practices [34 52] Furthermore slashand burn which is a common practice in the area during fieldpreparation might have also contributed to the depletion ofsoil OC


Table 6 Soil pH electrical conductivity and calcium carbonate

Pedon Horizon Depth (cm) pH (1 25) ΔpH EC (dSmminus1) CaCO3 ()(H2O) (KCl)

A-1

Ap 0ndash18 60 51 09 010 023Bw1 18ndash25 61 56 05 010 019Bw2 25ndash35 60 53 07 008 015CB 35ndash110 63 56 07 008 024

A-2

A 0ndash18 65 58 07 015 025Ad 18ndash27 67 59 08 010 017Bt1 27ndash37 61 54 07 007 020Bt2 37ndash50 63 56 07 007 035BC 50ndash80 64 57 07 005 031

A-3

Ap 0ndash22 67 59 08 023 028A 22ndash33 65 57 08 021 025Bt1 33ndash45 63 56 07 014 023Bt2 45ndash63 63 55 08 009 025BC 63ndash85 60 53 07 009 027

A-4


A-5

Ap 0ndash17 55 47 08 011 016A 17ndash55 57 49 08 008 015Bss1 55ndash116 61 50 11 006 022BCss2 116ndash150 65 58 07 006 027

A-6 Ap 0ndash20 71 64 07 024 039

A-7

A 0ndash29 61 51 10 015 019Bss1 29ndash48 61 53 08 013 021Bss2 48ndash105 66 53 13 007 029BCss 105ndash150+ 68 59 09 016 031

The total N content of the surface soils ranged 011 to024 which could be rated as low to medium [51] Similarto OC total N content decreased with depth in all pedons(Table 7) Soils with less than 007 total N have limitedN mineralization potential while those having greater than015 total N would be expected to mineralize a significantamount of N during the succeeding crop cycle showing thatmost of the soils have good potential of Nmineralization [53]A strong positive correlation (119903 = 092 119901 lt 0001) was ob-served between soil OM and total N indicating the mainsource of N in the soils is organic matter (Table 10)

The carbon to nitrogen ratio (C N) showed numericallynarrow variation among the pedons and irregular patternwith increasing depth This is in contrast to the findings ofprevious study [54] where C N ratio varied markedly due tochange in land use and decreased consistently with increasingdepth Generally most of the values were found between 10 1and 13 1 showing optimal range of mineralization

The available phosphorus content of the pedons rangedfrom 022 in subsoil of Pedon A-7 to 1083mg kgminus1 in surfacelayer of PedonA-6 (Table 7) which could be categorized fromvery low to very high [55] Relatively the maximum available

P was recorded in pedon where the pH was neutral (71)the pH value where P fixation is low P-Olsen between 12and 18mg kgminus1 is considered as sufficient [56] and hence theavailable P in surface horizons of all pedons was in sufficientrange except Pedon A-7 It was also reported that soil P ismore available in warm soil than in cool soil [53] ThereforeP availability in the soilsmight have been favored by thewarmclimatic condition of the study area along with the preferredpH range Available P values declined with increasing depthwhich could be attributed to decrease in soil OM as was alsoasserted by their positive significant (119903 = 071 119901 lt 001)correlation (Table 10)The increase in clay content with depthcould have also contributed to decrease available P althoughthis was not confirmed by the correlation analysis

The available potassium content of the soils of all thepedons varied from 113 to 1155mg kgminus1 (Table 7) and could becategorized frommedium to very high [55]Thehighest avail-able K (1155mg kgminus1) was recorded in the surface horizon ofPedon A-4 whereas the smallest value (115mg kgminus1) was inPedon A-5 and the values generally decreased with depthHigh values of available K in 0ndash40 cm depth compared tothose in 40ndash120 cm depth were observed and were attributed


Table 7 Organic carbon total nitrogen carbon to nitrogen ratio available P and available K contents of soils of Abobo area

Pedon Horizon Depth (cm) OC () TN () C N Available P (mg kgminus1) Available K (mg kgminus1)

A-1


A-2


A-3


A-4


A-5


A-6 Ap 0ndash20 259 023 11 10832 755

A-7


to the difference in weathering rate [57] Potassium removalfrom primary minerals requires hydronium ion which dis-sociates from organic and inorganic acids in the soil solution[4] Obviously the supply of hydronium is relatively higherin the surface horizon due to the relatively higher contentsof organic matter and root activities which release CO2 Thedissolution of CO2 forms H2CO3 and ultimately hydroniumionThis process might have resulted in higher available K insurface than subsurface layers Relatively the highest availableK (1155mg kgminus1) was recorded in surface horizon of PedonA-4 where the OC was highest (298)

343 Cation Exchange Capacity Exchangeable Bases andBase Saturation The overall cation exchange capacity (CEC)of the soils ranged between 2066 and 4470 cmolc kg

minus1

(Table 8) which is medium to very high [58] The smallestvalue was recorded under Pedon A-6 which was undercontinuous maize cultivation whereas the highest value wasrecorded under Pedon A-7 of forest land Previous studiesindicated that deforestation and subsequent cultivation ledto decline in CEC [39 59 60] On the other hand theCEC clay varied from 3670 to 7796 cmolc kg

minus1 suggestinggreater proportions of 2 1 clay mineral most probably

montmorillonite andor illite with more nutrient reservesSoils with low CEC are more likely to develop deficienciesin potassium (K+) magnesium (Mg2+) and other cationswhile high CEC soils are less susceptible to leaching of thesecations [61] Generally CEC is a very important soil propertyinfluencing soil structure stability nutrient availability soilpH and the soilrsquos reaction to fertilizers and other ameliorants[58] Generally the soils of the study area had good nutrientretention and buffering capacity due to the high status ofCEC

The results revealed that the contents of exchangeable CaandMg varied from 1024 to 2912 and 376 to 898 cmolc kg

minus1respectively whereas exchangeable K varied from 029 to295 cmolc kg

minus1 In accordance with the ratings of [62] thesoils are categorized under high to very high with respectto Ca and Mg contents and low to very high in terms ofK The contents of exchangeable Ca and Mg (2912 and898 cmolc kg

minus1 resp) were highest under PedonA-7 of forestland whereas the lowest values (1024 and 376 cmolc kg

minus1resp) were recorded under Pedons A-4 and A-6 of cultivatedlands These differences could be due to crop uptake andrecycling of nutrients under cultivated and forest landsrespectively


Table 8 Exchangeable bases (Ca Mg K and Na) cation exchange capacity (CEC) calcium to magnesium ratio (Ca Mg) and percent basesaturation (BS) of the soils

Pedon Depth (cm) Exchangeable bases cmolc kgminus1 CEC cmolc kg

minus1

ESP () Ca Mg PBS ()Ca Mg K Na TEBlowast Soil Caly

A-1

0ndash18 1250 570 075 011 1307 2554 7297 04 219 7518ndash25 1357 861 078 014 1621 2392 6644 06 159 9625ndash35 1102 434 071 016 2037 2413 6522 07 254 6835ndash110 1335 611 075 016 2037 2640 7543 06 218 77

A-2

0ndash18 1463 652 199 009 2323 2571 5041 03 224 9018ndash27 1501 607 176 010 2287 2502 4721 04 247 9127ndash37 1562 596 142 008 2308 2601 4563 03 262 8937ndash50 1320 701 157 010 2188 2596 3994 04 188 8450ndash80 1374 668 098 013 2153 2544 4800 05 206 85

A-3


A-4


A-5


A-6 0ndash20 1281 376 193 011 1861 2066 6261 05 341 90

A-7

0ndash19 2033 390 054 022 2899 3508 7473 06 521 8319ndash48 2597 844 041 113 3595 3738 6922 30 308 9648ndash105 2838 877 033 135 3883 4470 6769 30 324 87105ndash150+ 2912 898 033 141 3984 4356 6406 32 324 91

lowastTEB = total exchangeable bases

The exchange complex was found to be dominated by Cafollowed by Mg K and Na which could be considered asappropriate for plant growth Cations in productive agricul-tural soils are present in the order Ca2+ gtMg2+ gt K+ gt Na+and deviations from this order can create ion-imbalanceproblems for plants [46] Ca Mg ratio of the pedons didnot reveal deficiency for both cations [58] however all ofthe pedons were categorized under low (1 to 4) availabilityfor Ca except surface horizon of Pedon A-7 which couldbe categorized under balanced availability The approximateoptimum range of Ca Mg ratio formost crops is between 3 1and 4 1 [17] If it is less than 31 P uptake may be inhibited

The exchangeable Na accounted only for 03 to 32 ofthe exchangeable cations with lowest and highest values inPedons A-2 and A-7 respectively (Table 8) The Na contentthroughout the profiles of all pedons was low indicating theabsence of sodicity problem Additionally the percent basesaturation of the pedons ranged from 64 to 98 (Table 8)which could be categorized under high to very high contents[58] Relatively lower percent base saturation (75) in the

surface soils was observed under Pedons A-1 and A-5 ofmaize farms The reason might be the depletion of bases dueto continuous cultivation of maize It was concluded thatdeforestation and conversion of forest land to agriculturaluses resulted in significant change in percent base saturation[59] The highest value (3984 cmolc kg

minus1) of total exchange-able bases was recorded under lower slope Pedon A-7 offorest land whereas the smallest value (1307 cmolc kg

minus1) wasrecorded under Pedon A-1 of upper slope cultivated landThe difference was attributed by the combined effect of slopeposition and land use

344 Micronutrients The contents of available micronutri-ents in the pedons generally decreased with increasing depthThe soils of the study area were found to be high in Fe (1036to 3658mg kgminus1) medium to high in Mn and Zn (1033 to4218 and 063 to 475mg kgminus1 resp) and low to medium inCu (148 to 423mg kgminus1) contents [55] (Table 9) Fertilizerresponse is unlikely for values greater than 100 30 15 and10 for Fe Mn Zn and Cu respectively [53] Accordingly


Table 9 Available micronutrient contents of the soil of Abobo area

Pedon Horizon Depth (cm) Micronutrients (mg kgminus1)Fe Mn Zn Cu

A-1

Ap 0ndash18 2887 4218 475 386Bw1 18ndash25 2491 3821 305 359Bw2 25ndash35 1743 2746 121 317CB 35ndash110 1955 3513 063 210

A-2

A 0ndash18 2403 4123 464 423Ad 18ndash27 2561 3451 413 300Bt1 27ndash37 2035 2906 207 334Bt2 37ndash50 2012 1945 113 251BC 50ndash80 1822 2176 110 276

A-3

Ap 0ndash22 1846 3881 459 375A 22ndash33 1653 1494 341 297Bt1 33ndash45 1297 1065 225 318Bt2 45ndash63 1426 1321 113 237BC 63ndash85 1266 1033 111 148

A-4


A-5

Ap 0ndash17 3658 4094 242 393A 17ndash55 3144 2816 186 358Bss1 55ndash116 2075 1993 137 322BCss2 116ndash150 1826 2074 098 176

A-6 Ap 0ndash20 1926 3400 473 357

A-7

A 0ndash19 2961 4052 164 215Bss1 19ndash48 2282 2267 135 226Bss2 48ndash105 1271 1521 112 244BCss 105ndash150+ 1036 1319 089 155

the soils of the study are not deficient in Fe Mn and Znwhereas the lower values of available Cu in some of thepedons indicate the potential deficiency of the element withcontinuous cropping Previous findings have also indicatedCu deficiency in Ethiopian soils as a wide spread problem[36 41]

The contents of Fe and Mn were relatively highest inPedons A-5 andA-1 respectively Numerically wide variationwas not observed inMn contents among the surface horizonsof the pedonsThe highest values of Zn (475mg kgminus1) andCu(423mg kgminus1) were observed in surface horizons of PedonsA-1 and A-2 respectively whereas the corresponding lowestvalues (164 and 215 resp) were recorded in Pedon A-7 Rela-tively higher values of availablemicronutrients were expectedunder forest land use as compared to the cultivated landsHowever the reverse situationwas observed in this studyThedifference probably is due to texture finely textured soils highin clay are abundant in micropores in which organic mattercan find physical protection from microbial decompositionwhich is a potential source ofmicronutrients Contrary to thisstudy significantly higher (119901 lt 001) values ofmicronutrientswere observed in the natural and plantation forests than

cultivated land [63] Positively significant (119903 = 080119901 lt 001)correlationwas observed betweenMnand soilOM(Table 10)

35 Classification of Soils of AboboArea Thesoils of the studyarea were classified according to WRB [18] and Soil Taxon-omy [19] which is presented in Figure 1 The morphologicalproperties in the field description and the physicochemicalanalysis results of the samples collected from every identifiedhorizon were used for the classifications

351 Soil Classification Based on WRB Legend All pedonshadwell-structured dark surface horizons having color valuesof 3 when moist and 5 or less when dry with one unit lessthan the parent material in both cases The surface layers ofthe pedons contain more than 06 percent organic carbonbase saturation (by 1M NH4OAc) of 50 percent or morethroughout the horizon (Table 8) fulfilling the diagnosticcriteria for mollic horizon except Pedons A-1 and A-4which failed to fulfill the horizon thickness requirement Thesubsurface horizon of Pedon A-1 had redder hue highervalue and chroma as well as higher clay content than theoverlying and underlying layers The layer was greater than


Table10C

orrelatio

nmatrix

forlinearrelationships

betweensoilparameterso

fAbo

boarea

Sand

Silt

Clay

120588 119887TP

AWC

pHOM

TNAv

PCa

Mg

CEC

FeMn

ZnCU

Sand

100

Silt

031

100

Clayminus0

78lowastlowastlowastminus0

84lowastlowastlowast

100

120588 119887015

002

minus010

100

TPminus0

28014

007minus0


100

AWCminus0

31011

011

minus060lowast

061lowast

100

pH024

015

minus024

021

minus021

007

100

OM

025

057lowastminus0

52lowastminus0

35033

019

007

100

TN034

053lowastminus0

55lowastminus0

33030

014

013


100

AvP

012

047

minus038

minus011

019

019

05lowast

071lowastlowast

071lowastlowast

100

Ca021

032

009

minus011

minus020

006

021

008

minus002minus0

1410

0Mg

006

065lowastminus0

46minus0

31039

018minus0


075lowastlowast

046minus0

2510

0CE

Cminus0

06minus0

51lowast

037

minus009

minus020minus0

07minus0

12minus0

002

001minus0

21073lowastlowastminus0

1710

0Fe

011

043

minus035

minus036

038

006minus0

44057lowast

059lowast

007minus0


0510

0Mn

006

065lowastminus0

46minus0

31039

018minus0


075lowastlowast

063lowastminus0

25043minus0

17068lowastlowast

100

Zn002

051lowastminus0

35minus0

50lowast

059lowast

038

031

057lowast

055lowast

063lowastminus0

24058lowastminus0

44032

058lowast

100

CUminus0

36033

minus001minus0

63lowast


055minus0

23026

020

0200minus0

35040minus0

39036

040

058lowast

100

lowastSign

ificant

at119901le005lowastlowast119901le001andlowastlowastlowast119901le0001

120588 119887=bu

lkdensity

TP=totalp

orosity

AWC=availablew

ater

contentOM

=organicm

atterTN

=totaln

itrogenA

vP=availablep

hospho

rusCE

C=catio

nexchange

capacity


N

0 3100 6200 93001550(Kms)

Soil typeHaplic CambisolsMollic LeptosolsMollic Vertisols

Vertic LuvisolsLake

8∘299840030

998400998400N

8∘09984000998400998400N

7∘57

99840030

998400998400N

7∘55

9984000998400998400N

7∘52

99840030

998400998400N

7∘50

9984000998400998400N

7∘47

99840030

998400998400N

8∘299840030

998400998400N

8∘09984000998400998400N

7∘57

99840030

998400998400N

7∘55

9984000998400998400N

7∘52

99840030

998400998400N

7∘50

9984000998400998400N

7∘47

99840030

998400998400N

34∘27

99840030

998400998400E 34∘30

9984000998400998400E 34

∘32

99840030

998400998400E 34∘35

9984000998400998400E 34

∘37

99840030

998400998400E

34∘27

99840030

998400998400E 34∘30

9984000998400998400E 34

∘32

99840030

998400998400E 34∘35

9984000998400998400E 34

∘37

99840030

998400998400E

Figure 1 Soil map of the study area

Table 11 Diagnostic horizons properties quantifiers and soil types of Abobo area according to WRB

Pedon Diagnostic horizon Diagnostic properties Soil typeSurface Subsurface

A-1 mdash Cambic mdash Haplic Cambisols (eutric)A-2 Mollic Argic Vertic Vertic Luvisols (hypereutric)A-3 Mollic Argic Vertic Vertic Luvisols (hypereutric)A-4 mdash Argic Vertic Vertic Luvisols (hypereutric)A-5 Mollic Vertic Vertic Mollic Vertisols (hypereutric)A-6 Mollic mdash mdash Mollic Leptosols (eutric)A-7 Mollic Vertic Vertic Mollic Vertisols (hypereutric)

15 cm in thickness with clay loam in texture and moderatelydeveloped structure The layer was therefore qualified forcambic horizon and the pedon was classified as CambisolsThe pedon also had base saturation (by 1M NH4OAc) of 50percent or more throughout the profile qualifying for eutricbut without any noticeable prefix qualifier Thus the pedonwas classified as Haplic Cambisols (eutric) (Table 11)

Pedons A-2 A-3 and A-4 had subsurface horizons withdistinct higher clay content than the overlying horizons

qualifying for argic subsurface diagnostic horizon Conse-quently the three pedons were classified under Luvisols Thesoils also exhibited vertic properties and had base saturation(by 1MNH4OAc) of 50 percent or more throughout between20 and 100 cm from the soil surface and 80 percent or morein some layer within 100 cm of the soil surface qualifyingvertic prefix and hypereutric suffix qualifiers Finally thethree pedons were classified as Vertic Luvisols (hypereutric)On the other hand Pedons A-5 and A-7 possessed subsurface


Table 12 Diagnostic horizons and soil types of Abobo area according to Soil Taxonomy

Pedon Diagnostic horizon SubgroupSurface Subsurface

A-1 Mollic Cambic Typic HaplusteptsA-2 Mollic Argillic Vertic HaplustalfsA-3 Mollic Argillic Vertic HaplustalfsA-4 Mollic Argillic Vertic HaplustalfsA-5 Mollic Vertic Typic HaplustertsA-6 Mollic mdash Lithic UstorthentsA-7 Mollic Vertic Typic Haplusterts

horizon having greater than 30 clay throughout wedge-shaped structure with cracks that open and close periodicallyand thickness of 25 cm ormore which qualify them for verticdiagnostic horizons Thus the two pedons are classified asMollic Vertisols (hypereutric) The qualifier hypereutric wasused for the second level classification due to their highpercentage of base saturation The remaining pedon (A-6)had shallow depth with extremely gravelly subsurface Asa result the pedon was classified as Leptosols The pedonhad mollic horizon base saturation (by 1M NH4OAc) of 50percent or more and therefore classified as Mollic Leptosols(eutric)

352 Soil Classification Based on Soil Taxonomy All the soilprofiles had thick (18 to 55 cm) surface horizons havingmoistcolor of 10YR 34 and darker weak to moderately strongstructureThe organic carbon content of the surface horizonsof the pedons ranged from 119 to 298 with percent basesaturation of greater than 50 (by 1M NH4OAc) Thus all thepedons possessed mollic epipedon The subsurface horizonof Pedon A-1 had higher chroma higher value redder hueor higher clay content than the underlying and overlyinghorizons qualifying cambic subsurface diagnostic horizonand it was classified as Inceptisols It was classified underUstepts due to its ustic moisture regime and the pedon wasfurther classified as Haplustepts and Typic Haplustepts(Table 12)

Pedons A-2 A-3 and A-4 had an argillic horizon andhence categorized under the order Alfisols [19] The pedonswere further grouped under Ustalfs at suborder level due totheir ustic soil moisture regime and Haplustalfs and VerticHaplustalfs at great group and subgroup levels respectivelydue to their vertic properties

Pedons A-5 and A-7 had 30 percent and more clay andexhibit slicken sides and cracks that open and close periodi-cally Thus the pedons were classified under Vertisols If notirrigated during the year the cracks remained opened for 90or more cumulative days per year qualifying it for Ustertssuborder and Haplusterts and Typic Haplusterts at greatgroup and subgroup respectively Pedon A-6 had shallowdepth with extremely gravelly subsurface and classified asEntisols and Orthents suborder The pedon further classifiedasUstorthents suborders due to its usticmoisture regimeThepedon had also a lithic contact within 50 cm of the mineralsoil surface and hence classified as Lithic Ustorthents

4 Conclusion

Field study was carried out to characterize and classify soilsof Abobo area western Ethiopia The soils were thoroughlyexamined and differentiated along north-south transectbased on observable site and soil characteristics includingslope soil depth and texture following free survey methodSeven representative pedons (A-1 to A-7) were opened anddescribed across the study area The results of the studyrevealed variation in morphological physical and chemicalproperties of the soils across the study area which indicatetheir variation in productive potential and managementrequirements for specific agricultural use

Four soil types Haplic Cambisols (eutric) Vertic Luvisols(hypereutric) Mollic Leptosols (eutric) and Mollic Verti-sols (hypereutric) were identified according to WRB andwith their Soil Taxonomy equivalent to Typic HaplusteptsVertic Haplustalfs Lithic Ustorthents and Typic Haplus-terts respectively Therefore using the soils according totheir potential and suitability and by applying the requiredmanagement would optimize agricultural production in asustainable manner Special emphasis should also be given tosoil OMmanagement as it plays a major role in soil physicalchemical and biological quality Additionally integrated soilfertility management should be implemented in the area tooptimize and sustain crop production

Competing Interests

The authors declare that they have no competing interests

Acknowledgments

The authors would like to thank the Gambella AgriculturalTechnical Vocational Education and Training College fortheir financial support The staffs of Addis Ababa NationalSoil Testing Laboratory are greatly acknowledged for theircooperation during soil analysis

References

[1] A Esayas and B Debele ldquoSoil survey in Ethiopia past presentand futurerdquo in Proceedings of the 8th Conference Soils forSustainable Development pp 1ndash10 Ethiopian Society of SoilScience Addis Ababa Ethiopia April 2006


[2] W E H Blum and M C Laker ldquoSoil classification and soilresearchrdquo in Soil Classification A Global Desk Reference HEswaran T Rice and B A Stewart Eds pp 43ndash51 CRC Press2003

[3] S Nortcliff ldquoClassification Need for systemsrdquo in Encyclopediaof Soil Science R Lal Ed vol 1 pp 227ndash229 2006

[4] S W Buol R J Southard R C Graham and P A McDanielSoil Genesis and Classification Iowa State Press Ames IowaUSA 5th edition 2003

[5] MANwachokor andFOUzu ldquoUpdated classification of somesoil series in Southwestern Nigeriardquo Journal of Agronomy vol 7no 1 pp 76ndash81 2008

[6] J Wang F Bojie Q Yang and C Liding ldquoSoil nutrients inrelation to land use and landscape position in the semi-aridsmall catchments on the loess plateau in Chinardquo China Journalof Arid Environment vol 48 pp 537ndash550 2000

[7] D Mulugeta and B Sheleme ldquoCharacterization and classifica-tion of soils along the toposequence of KindoKoye Watershedin Southern Ethiopiardquo East African Journal of Sciences vol 4no 2 pp 65ndash77 2011

[8] D Pal and Y G Selassie ldquoPhysicochemical soil properties ofTendaho irrigation area and their significance in sustainablesugarcane productionrdquo in Proceedings of the 12th EthiopianSociety of Soil Science (ESSS rsquo11) pp 358ndash370 Addis AbabaEthiopia March 2011

[9] D Kassahun ldquoStatus of satellite-based soil surveys in Ethiopiapotential and constraintsrdquo in Proceedings of the 8th ConferenceSoils for Sustainable Development pp 11ndash36 Ethiopian Societyof Soil Science Addis Ababa Ethiopia April 2006

[10] Selkhozpromexport Baro-Akobo Basin Master Plan Study ofWater and Land Resources of the Gambella Plain Anex 4 Soiland Their Potential Uses All Union Foreign Economic Corpora-tions Soyuziprovodkhoz inistitute Moscow Russia 1990

[11] Yeshibir Gambella Peoplersquos Regional State Land-useland Allot-ment Study Section 9 Soils Yeshibir Addis Ababa Ethiopia2003

[12] S Damene M Assen and A Eyasu ldquoCharacteristics and classi-fication of the soils of Tenocha-Wenchacher Micro-catchmentSouth-west Shewa Ethiopiardquo Ethiopian Journal of Natural Re-sources vol 9 no 1 pp 37ndash62 2007

[13] A Davidson Reconnaissance Geology and Geochemistry ofSouthwest Ethiopia Ethiopian Institute of Geological SurveysAddis Ababa Ethiopia 1983

[14] Woody Biomass Investment Strategic Plan and Program(WBISPP) A Strategic Plan for the Gambella Regional StateAddis Ababa Ethiopia 2001

[15] D Dent and A Young Soil Survey and Land Evaluation GeorgeAllen and Unwinpublishe Ltd 1981

[16] Food and Agriculture Organization (FAO) Guidelines for SoilDescription Food and Agriculture Organization of the UnitedNations Rome Italy 2006

[17] J R Landon Ed Booker Tropical Soil Manual A Handbookfor Soil Survey and Agricultural Land Evaluation in the Tropicsand Subtropics Longman Scientific andTechnical LondonUK1991

[18] International Union of Soil Science (IUSS) Working GroupldquoWorld Reference base for Soil Resources a framework forinternational classification correlation and communication2nd Editionrdquo World Soil Resources Reports 103 FAO RomeItaly 2006

[19] Soil Survey Staff Keys to Soil Taxonomy Department of Agri-culture Natural Resources Conservation Service WashingtonDC USA 10th edition 2006

[20] G R Black and K H Hertge ldquoBulk densityrdquo inMethods of SoilAnalysis A Klute Ed pp 377ndash382 SSSA Madison Wis USA1986

[21] K H Tan Soil Sampling Preparation and Analysis MarcelDekker New York NY USA 1996

[22] G J Bouyoucos ldquoHydrometer method improvement for mak-ing particle size analysis of soilsrdquo Agronomy Journal vol 54 pp179ndash186 1962

[23] P K Gupta Soil Plant Water and Fertilizer Analysis 2004[24] S Sertsu and T Bekele Eds Procedure for Soil and Plant

Analysis National Soil Research Centre Ethiopian AgriculturalResearch Organization Addis Ababa Ethiopia 2000

[25] A Walkley and I A Black ldquoAn examination of the degtjareffmethod for determining soil organic matter and a proposedmodification of the chromic acid titrationmethodrdquo Soil Sciencevol 37 no 1 pp 29ndash38 1934

[26] J M Bremner and C S Mulvaney ldquoNitrogen-totalrdquo inMethodsof Soil Analysis Part 2 Chemical andMicrobiological PropertiesA L Page Ed pp 595ndash641 SSSA Madison Wis USA 1982

[27] S R Olsen and L E Somers ldquoPhosphorusrdquo inMethods of SoilAnalysis Part 2 A L Page R H Miller and D R Keeney Edspp 403ndash430 SSSA Madison Wis USA 1982

[28] D Knudsen G A Peterson and P F Pratt ldquoPotassiumrdquo inMethods of Soil Analysis Chemical and Microbiological Proper-ties A L Page Ed pp 229ndash230 America Society of AgronomyMadison Wis USA 1982

[29] L P Van Reeuwijk Procedures for Soil Analysis Interna-tional Soil Reference and Information Center AmsterdamTheNetherlands 4th edition 1993

[30] M L Jackson Soil Chemical Analysis Prentice-Hall EnglewoodCliffs NJ USA 1970

[31] R E Nelson ldquoCarbonate and gypsumrdquo inMethods of Soil Anal-ysis Part 2 A L Page R H Mille and D R Keeney Eds vol9 pp 181ndash197 SSSA Madison Wis USA 1982

[32] Statistical Analysis System (SAS) Institute Inc 2008SASSTAT92 Userrsquos Guide SAS Institute Cary NC USA 2008

[33] R C Graham ldquoFactors of soil formation topographyrdquo in SoilsBasic Concepts and Future Challenges G Certini and RScalenghe Eds pp 151ndash162 Cambridge University Press 2006

[34] O Dengiz and A Info ldquoMorphology physicochemical proper-ties and classification of soils on terraces of the Tigris River inthe South-east Anatolia Region of Turkeyrdquo Journal of Agricul-tural Sciences vol 16 pp 205ndash212 2010

[35] O Dengiz S Ic and F E Sarioglu ldquoPhysico-chemical andmor-phological properties of soils for Castanea sativa in the centralblack sea regionrdquo International Journal of Agricultural Researchvol 6 no 5 pp 410ndash419 2011

[36] A Ali A Esayas and S Beyene ldquoCharacterizing soils of DelboWegene Watershed Wolaita Zone southern Ethiopia for plan-ning appropriate land managementrdquo Journal of Soil Science andEnvironmental Management vol 1 no 8 pp 184ndash199 2010

[37] R Schaetzl and S Anderson Soils Genesis and GeomorphologyCambridge University Press Cambridge UK 2005

[38] S W Buol ldquoPedogenic processes and pathways of horizon dif-ferentiationrdquo in Soils Basic Concepts and Future Challenges GCertini and R Scalenghe Eds pp 11ndash21 Cambridge UniversityPress 2006


[39] A Mojiri H A Aziz and A Ramaji ldquoPotential decline in soilquality attributes as a result of land use change in a hillslopein Lordegan Western Iranrdquo African Journal of AgriculturalResearch vol 7 no 4 pp 577ndash582 2012

[40] A M Michael Irrigation Theory and Practice Noida IndiaVikas 2nd edition 2008

[41] E Abayneh Characteristics genesis and classification of reddishsoils from Sidamo Ethiopia [PhD thesis] Universiti PutraMalaysia Seri Kembangan Malaysia 2005

[42] United States Department of Agriculture (USDA) Soil QualityIndicators USDA Natural Resources Conservation ServiceWashington DC USA 2008

[43] United States Department of Agriculture (USDA) Soil Taxon-omy A Basic System of Soil Classification for Making and Inter-preting Soil Surveys Agriculture Handbook Natural ResourcesConservation Service Number 436 United States Departmentof Agriculture (USDA) Washington DC USA 2nd edition1999

[44] D Hillel Introduction to Environmental Soil Physics ElsevierScience Amsterdam The Netherlands 2004

[45] D A Horneck D M Sullivan J S Owen and J M Hart SoilTest Interpretation Guide Oregon State University 2011

[46] H L Bohn B L McNeal and G A Orsquoconnor Soil ChemistrJohn Wiley amp Sons 3rd edition 2001

[47] L A Vorobrsquoeva and A A Avdonrsquokin ldquoPotential soil aciditynotions and parametersrdquo Eurasian Soil Science vol 39 no 4pp 377ndash386 2006

[48] M C Amacher K P OrsquoNeill and C H Perry ldquoSoil vital signsa new soil quality index (SQI) for assessing forest soil healthrdquoUSDA Forest ServicemdashResearch Paper RMRS-RP 2007

[49] J Scianna R Logar and T Pick Testing and Interpreting Salt-affected Soil for Tree and Shrub Plantings Natural ResourcesConservation Service Plant Materials Technical Note No MT-60 2007

[50] P N Soltanpour and R H Follet Soil Test Explanation Col-orado State University Cooperative Extension No 0502 1999

[51] T Tadese ldquoSoil plant water fertilizer animalmanure and com-post analysisrdquo Working Document 13 International LivestockResearch Center for Africa Addis Ababa Ethiopia 1991

[52] S Beyene ldquoCharacterization of soils along a toposequencein Gununo area Southern Ethiopiardquo Journal of Science andDevelopment vol 1 no 1 pp 31ndash41 2011

[53] T K Hartz Soil Testing for Nutrient Availability Proceduresand Interpretation for California Vegetable Crop ProductionUniversity of California 2007

[54] H Gebrekidan and W Negassa ldquoImpact of land use and man-agement practices on chemical properties of some soils of BakoareasWestern EthiopiardquoEthiopian Journal of Natural Resourcesvol 8 no 2 pp 177ndash197 2006

[55] J B Jones Agronomic Handbook Management of Crops Soilsand Their Fertility CRC Press Boca Raton Fla USA 2003

[56] R N Carrow L Stowell W Gelernter S Davis R R Duncaand J Skorulski Clarifying Soil Testing III SLAN (SufficiencyLevel of Available Nutrients) Sufficiency Ranges and Recommen-dations 2004

[57] Z Liu X Chen Y Shi and M Niu ldquoAvailable K and totalorganic C accumulation in soil with the utilization ages ofthe vegetable greenhouses in the Suburb of Shenyangrdquo in Pro-ceedings of the 2nd International Conference on EnvironmentalScience and Technology (IPCBEE rsquo11) vol 6 pp 204ndash206IACSIT Press 2011

[58] P Hazelton and B Murphy Interpreting Soil Test Results WhatDo All the Numbers Mean CSIRO Victoria Australia 2ndedition 2007

[59] N Emiru and H Gebrekidan ldquoInfluence of land use changesand soil depth on cation exchange capacity and contents ofexchangeable bases in the soils of Senbat Watershed WesternEthiopiardquo Ethiopian Journal of Natural Resources vol 11 no 2pp 195ndash206 2009

[60] B Ashasi A Jalalian and N Honarjoo ldquoThe comparison ofsome soil quality indices in different land use of Ghaneh AghajWatershed of Semirom Isfahan Iranrdquo International Journal ofEnvironmental and Earth Science vol 1 no 2 pp 76ndash80 2010

[61] Cornell University Cooperative Extension (CUCE) CationExchange Capacity (CEC) Agronomy Fact Sheet Series No 22Department of Crop and Soil Sciences College of Agricultureand Life Sciences Cornell University 2007

[62] Food and Agriculture Organization (FAO) Plant Nutrition forFood Security A Guide for Integrated Nutrient Managementvol 16 of Fertilizer and Plant Nutrition Bulletin Food andAgriculture Organization (FAO) Rome Italy 2006

[63] E Molla H Gebrekidan T Mamo and M Assen ldquoEffects ofland-use change on selected soil properties in the Tera GedamCatchment and adjacent agroecosystems North-West Ethio-piardquo Ethiopian Journal of Natural Resources vol 11 no 1 pp35ndash62 2009

Submit your manuscripts athttpwwwhindawicom

Forestry ResearchInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Environmental and Public Health

Journal of



EcosystemsJournal of


MeteorologyAdvances in

EcologyInternational Journal of


Marine BiologyJournal of


Hindawi Publishing Corporationhttpwwwhindawicom

Applied ampEnvironmentalSoil Science

Volume 2014

Advances in


Environmental Chemistry

Atmospheric SciencesInternational Journal of



Waste ManagementJournal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal of

Geophysics


Geological ResearchJournal of

EarthquakesJournal of


BiodiversityInternational Journal of


ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

OceanographyInternational Journal of


The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Journal of Computational Environmental SciencesHindawi Publishing Corporationhttpwwwhindawicom Volume 2014


ClimatologyJournal of


Agriculture has been the mainstay of Ethiopian economyfor centuries and will remain the same for the coming manyyears [8] However reliable soils data which are the pre-requisite for the design of appropriate land use systems andsoilmanagement practices are not adequately availableMostof the studies undertaken so far were localized mostly toareas close to major transportation networks and some of theavailable data are not currently used as they are 20ndash30 yearsold [9]

All the previous studies conducted in Gambella thepresent study area were at small scale [10 11] National andregional small-scale studies seem to be inadequate in provid-ing basic soil data that can help to manage soils according tolocal variability [12] This study was therefore initiated andcarried out in Abobo area of Gambella region to characterizeand classify the soils of the area in detail

2 Materials and Methods

21 Description of the Study Area The study area Abobodistrict is located at 42 km south of Gambella town andabout 808 km west of Addis Ababa It lies between 07∘5010158404710158401015840to 08∘0110158405910158401015840N and 34∘2810158405910158401015840 to 34∘3410158403710158401015840E with altituderanging from 446 to 490 meters above sea level (masl) andslope from flat (02ndash05) to gently sloping (2ndash5)

The climate of the region is influenced by the tropicalmonsoon which is characterized by high rainfall in the wetperiod from May to October and little rainfall during thedry period from November to April [11] The average annualrainfall is 9555mm whereas the mean minimum and meanmaximum monthly temperatures range from 162 to 212∘Cand 321 to 382∘C respectively The region is drained by anumber of perennial rivers including Baro Alwero GilloAkobo and their tributaries

The geology of Abobo is characterized by undifferenti-ated Pleistocene Holocene deposits Granite gneisses schistsandstone and basalt are the rock types existing in the region[13] The major soils of Abobo District include Dystric andEutric Plinthosols Dystric and Chromic Cambisols EutricVertisols and Planosols where Cambisols occur at the upperslope north of Abobo while Plinthosols and Vertisols exist atthe middle and lower slopes respectively [11]

The Abobo district encompasses forest land woodlandshrub land grassland and cultivated land occupying 14308675227 5793 62997 and 19854 hectares (ha) respectively[14] The forest cover is continuously declining due to set-tlement and agricultural expansion The major crops grownby farmers include maize (Zea mays L) sorghum (Sorghumbicolor) groundnut (Arachis hypogaea) and sesame (Sesa-mum aestivum) whereas cotton (Gossypium sp) and rice(Oryza sativa L) are cultivated by state farms and investorsoperating in and around the study area

22 FieldWork Prior to the start of the field soil descriptionsthe boundaries of the kebeles (the smallest administrativeunit) along the transect were delineated using digital mapof Gambella region and the soils within each kebele werethoroughly examined and differentiated based on observablesite and soil characteristics such as slope soil depth and

texture following free survey method [15] The approach wasto traverse the landscape along selected transects (north tosouth) by auger inspection at enough points to identify theexisting soils type and their boundaries

The study area was categorized into seven soil units afterinspecting 189 auger samples A representative soil pedon15 times 2m was opened in each identified soil unit and de-scribed in situ following theGuidelines for Field Soil Descrip-tion [16] General site information and soil description wererecorded and samples were collected from every identifiedhorizon Core samples were collected at different pointsacross each horizon Infiltration rates were measured intriplicate in each identified soil unit using double ringinfiltrometer [17]The rate wasmeasured by observing the fallof water within concentric cylinders (28 and 53 cm diameterwith 24 cmheight) driven 10 cmvertically into the soil surfacelayer

Based on the morphological properties and the labora-tory analysis the soils of the study areawere classified accord-ing to WRB [18] and Soil Taxonomy [19]

23 Laboratory Analysis The samples collected from identi-fied horizons of all pedons were air-dried and ground to passthrough 2mm sieve For the determinations of total N andOC a 05mm sieve was used Analyses of the physicochemi-cal properties were carried out following standard laboratoryprocedures

Bulk and particle densities were determined by core sam-pling [20] and pycnometer [21] methods respectively Parti-cle size distribution was determined by Bouyoucos hydrom-eter method [22] Total porosity was computed from themeasurements of soil dry bulk density (120588119887) and soil particledensity (120588119901) as

Porosity = 1 minus (120588119887120588119901) (1)

Water retention at field capacity (FC) and permanent wiltingpoint (PWP) was measured by employing pressure plateextraction methods [23] and available water content (AWC)was computed by subtracting values of permanent wiltingpoint from that of field capacity

Soil pH and electrical conductivity were measured usinga 1 25 soil to water ratio [24] whereas OC was determinedby wet digestion method [25] Total N was determined byKjeldahl wet digestion and distillation method [26] availableP by the modified Olsen method [27] and available K usingsodium acetate extractant [28] The CEC and exchangeablebases were extracted by 1M ammonium acetate (pH 7)method [29] In the extract exchangeable Ca and Mg weredetermined by atomic absorption spectrophotometer (AAS)and exchangeable K and Na by flame photometer Availablemicronutrients (Fe Mn Zn and Cu) of the soil were extract-ed by diethylene triamine pentaacetic acid (DTPA) methodas described in Tan [21] and determined using AAS Calciumcarbonate and gypsum contents were determined followingacid neutralization method [30] and Nelson procedure [31]respectively








= OCTotal N




CEC] lowast 100




CEC]

lowast 100

(2)









Table2Selected

morph

ologicalprop

ertie

softhe

pedo

ns

Pedo

nHorizon

Depth

(cm)

Boun

dary1

Color

Texture

(Feelm

etho

d)2

Structure3

Con

sistency4

Coarsefragm

ent()

Dry

Moist

A-1

Ap0ndash

18GS

10YR

36

10YR

33

CLMOV

MG

RSH

AFR

STSPL

mdashBw

118ndash25

GS

25Y

R46

25Y

R44

CLMOV

MA

BSH

AFR

STSPL

mdashBw

225ndash35

GS

25Y

R48

25Y

R46

CMOFMA

BSH

AFR

STP

Lmdash

CB35ndash110

mdash25Y

R46

25Y

R46

CMOFMA

BSH

AFR

STP

L47

A-2

A0ndash

18GS

10YR

43

10YR

32

CLMOFMG

RSH

RFR

STPL

mdashAd

18ndash27

CS10YR

43

10YR

32

CLMOFMA

BSH

AFR

STP

Lmdash

Bt1

27ndash37

CS25Y

R44

25Y

R43

CMOM

EAB

SHAFR

STP

Lmdash

Bt2

37ndash50

GS

25Y

R46

25Y

R45

CMOM

EAB

SHAFR

STP

Lmdash

BC50ndash80

mdash25Y

R46

25Y

R45

CMOM

EAB

SHAFR

STP

L21

A-3

Ap0ndash

22CS

75YR

33

75YR

33

CLMOFMG

RSH

AFR

STP

Lmdash

A22ndash33

CS75

YR33

75YR

32

CMOM

EAB

HAFR

VSTVPL

mdashBt1

33ndash4

5GS

5YR46

5YR44

CMOM

EAB

HAFR

VSTVPL

mdashBt2

45ndash6

3GS

5YR44

25Y

R43

CMOM

EAB

HAFR

VSTVPL

mdashBC

63ndash85

mdash5Y

R46

5YR44

CMOM

EAB

HAFR

VSTVPL

19

A-4

Ap0ndash

10CS

10YR

36

10YR

33

CLWE

FIG

RSH

AFR

STP

Lmdash

A10ndash19

CS10YR

34

10YR

33

CSTFMSB

VHAFISTP

Lmdash

Bt1

19ndash37

GS

75YR

44

75YR

33

CSTFMA

BVHAFISTP

Lmdash

Bt2

37ndash75

GS

5YR46

5YR34

CSTFMA

BHAFISTP

Lmdash

BC75ndash85

mdash5Y

R46

5YR44

CSTFMA

BSH

AFR

TSP

L23

A-5

Ap0ndash

17GS

10YR

37

10YR

31

CMOM

CAB

HAFR

STP

Lmdash

A17ndash55

GS

10YR

52

10YR

32

CSTC

OA

BVHAFISTP

Lmdash

Bss1

55ndash116

GS

25Y

52

25Y

42

CSTC

OA

BVHAV

FISTPL

mdashBC

ss2

116ndash

150

mdash10YR

52

10YR

32

CVS

TCO

AB

VHAV

FISTPL

mdashA-

6Ap

0ndash20

mdash10YR

43

10YR

32

LMOFMG

RSH

AFR

STP

Lmdash

A-7

A0ndash

29CS

10YR

32

10YR

21

CMOFMA

BSH

AFR

STP

Lmdash

Bss1

29ndash4

8GS

10YR

44

10YR

34

CSTV

CAB

EHAE

FIV

STV

PLmdash

Bss2

48ndash105

GS

10YR

36

10YR

32

CSTE

CAB

EHAE

FIV

STV

PLmdash

BCss

105ndash150+

mdash25Y

61

25Y

51

CSTE

CPR

EHAE

FIV

STV

PLmdash

1CS

=cle

arandsm

oothG

S=gradualand

smoo

th

2CL

=cla

yloam

C=cla

y3WE=weakST

=str

ongMO

=mod

erateVS

T=very

stron

gFI

=fin

eFM

=fin

eandmediumV

M=very

fineto

mediumM

C=medium

andcoarseM

E=mediumC

O=coarseV

C=very

coarseE

C=

extre

mely

coarseG

R=granularSB=subang

ular

blockyA

B=angularb

lockyPR

=prism

atic

4SH

A=slightly

hardV

HA=very

hardH

A=hardE

HA=extre

mely


stickyVS

T=very

stickyPL

=plasticSPL

=slightly

plasticV

PL=very

plasticFR=friableFI

=firmE

FI=extre

mely

firm




A-1


A-2


A-3


A-4


A-5



A-7












) AWC(volume )

FC PWP

A-1


A-2


A-3


A-4


A-5


A-6 Ap 0ndash20 120 253 5257 35 19 16

A-7























A-1


A-2


A-3


A-4


A-5


A-6 Ap 0ndash20 71 64 07 024 039

A-7










A-1


A-2


A-3


A-4


A-5


A-6 Ap 0ndash20 259 023 11 10832 755

A-7




minus1












minus1


A-1


A-2


A-3


A-4


A-5


A-6 0ndash20 1281 376 193 011 1861 2066 6261 05 341 90

A-7












A-1


A-2


A-3


A-4


A-5


A-6 Ap 0ndash20 1926 3400 473 357

A-7








Table10C

orrelatio

nmatrix



fAbo

boarea

Sand

Silt

Clay

120588 119887TP

AWC

pHOM

TNAv

PCa

Mg

CEC

FeMn

ZnCU

Sand

100

Silt

031

100

Clayminus0



100

120588 119887015

002

minus010

100

TPminus0

28014

007minus0


100

AWCminus0

31011

011

minus060lowast

061lowast

100

pH024

015

minus024

021

minus021

007

100

OM

025

057lowastminus0

52lowastminus0

35033

019

007

100

TN034

053lowastminus0

55lowastminus0

33030

014

013


100

AvP

012

047

minus038

minus011

019

019

05lowast

071lowastlowast

071lowastlowast

100

Ca021

032

009

minus011

minus020

006

021

008

minus002minus0

1410

0Mg

006

065lowastminus0

46minus0

31039

018minus0


075lowastlowast

046minus0

2510

0CE

Cminus0

06minus0

51lowast

037

minus009

minus020minus0

07minus0

12minus0

002

001minus0


1710

0Fe

011

043

minus035

minus036

038

006minus0

44057lowast

059lowast

007minus0


0510

0Mn

006

065lowastminus0

46minus0

31039

018minus0


075lowastlowast

063lowastminus0

25043minus0

17068lowastlowast

100

Zn002

051lowastminus0

35minus0

50lowast

059lowast

038

031

057lowast

055lowast

063lowastminus0

24058lowastminus0

44032

058lowast

100

CUminus0

36033

minus001minus0

63lowast


055minus0

23026

020

0200minus0

35040minus0

39036

040

058lowast

100

lowastSign

ificant


120588 119887=bu

lkdensity

TP=totalp

orosity

AWC=availablew

ater

contentOM

=organicm

atterTN

=totaln

itrogenA

vP=availablep

hospho

rusCE

C=catio

nexchange

capacity


N

0 3100 6200 93001550(Kms)


Vertic LuvisolsLake

8∘299840030

998400998400N

8∘09984000998400998400N

7∘57

99840030

998400998400N

7∘55

9984000998400998400N

7∘52

99840030

998400998400N

7∘50

9984000998400998400N

7∘47

99840030

998400998400N

8∘299840030

998400998400N

8∘09984000998400998400N

7∘57

99840030

998400998400N

7∘55

9984000998400998400N

7∘52

99840030

998400998400N

7∘50

9984000998400998400N

7∘47

99840030

998400998400N

34∘27

99840030

998400998400E 34∘30

9984000998400998400E 34

∘32

99840030

998400998400E 34∘35

9984000998400998400E 34

∘37

99840030

998400998400E

34∘27

99840030

998400998400E 34∘30

9984000998400998400E 34

∘32

99840030

998400998400E 34∘35

9984000998400998400E 34

∘37

99840030

998400998400E
















4 Conclusion



Competing Interests


Acknowledgments


References






































































Journal of












Volume 2014

Advances in









Geophysics





















= OCTotal N




CEC] lowast 100




CEC]

lowast 100

(2)









Table2Selected

morph

ologicalprop

ertie

softhe

pedo

ns

Pedo

nHorizon

Depth

(cm)

Boun

dary1

Color

Texture

(Feelm

etho

d)2

Structure3

Con

sistency4

Coarsefragm

ent()

Dry

Moist

A-1

Ap0ndash

18GS

10YR

36

10YR

33

CLMOV

MG

RSH

AFR

STSPL

mdashBw

118ndash25

GS

25Y

R46

25Y

R44

CLMOV

MA

BSH

AFR

STSPL

mdashBw

225ndash35

GS

25Y

R48

25Y

R46

CMOFMA

BSH

AFR

STP

Lmdash

CB35ndash110

mdash25Y

R46

25Y

R46

CMOFMA

BSH

AFR

STP

L47

A-2

A0ndash

18GS

10YR

43

10YR

32

CLMOFMG

RSH

RFR

STPL

mdashAd

18ndash27

CS10YR

43

10YR

32

CLMOFMA

BSH

AFR

STP

Lmdash

Bt1

27ndash37

CS25Y

R44

25Y

R43

CMOM

EAB

SHAFR

STP

Lmdash

Bt2

37ndash50

GS

25Y

R46

25Y

R45

CMOM

EAB

SHAFR

STP

Lmdash

BC50ndash80

mdash25Y

R46

25Y

R45

CMOM

EAB

SHAFR

STP

L21

A-3

Ap0ndash

22CS

75YR

33

75YR

33

CLMOFMG

RSH

AFR

STP

Lmdash

A22ndash33

CS75

YR33

75YR

32

CMOM

EAB

HAFR

VSTVPL

mdashBt1

33ndash4

5GS

5YR46

5YR44

CMOM

EAB

HAFR

VSTVPL

mdashBt2

45ndash6

3GS

5YR44

25Y

R43

CMOM

EAB

HAFR

VSTVPL

mdashBC

63ndash85

mdash5Y

R46

5YR44

CMOM

EAB

HAFR

VSTVPL

19

A-4

Ap0ndash

10CS

10YR

36

10YR

33

CLWE

FIG

RSH

AFR

STP

Lmdash

A10ndash19

CS10YR

34

10YR

33

CSTFMSB

VHAFISTP

Lmdash

Bt1

19ndash37

GS

75YR

44

75YR

33

CSTFMA

BVHAFISTP

Lmdash

Bt2

37ndash75

GS

5YR46

5YR34

CSTFMA

BHAFISTP

Lmdash

BC75ndash85

mdash5Y

R46

5YR44

CSTFMA

BSH

AFR

TSP

L23

A-5

Ap0ndash

17GS

10YR

37

10YR

31

CMOM

CAB

HAFR

STP

Lmdash

A17ndash55

GS

10YR

52

10YR

32

CSTC

OA

BVHAFISTP

Lmdash

Bss1

55ndash116

GS

25Y

52

25Y

42

CSTC

OA

BVHAV

FISTPL

mdashBC

ss2

116ndash

150

mdash10YR

52

10YR

32

CVS

TCO

AB

VHAV

FISTPL

mdashA-

6Ap

0ndash20

mdash10YR

43

10YR

32

LMOFMG

RSH

AFR

STP

Lmdash

A-7

A0ndash

29CS

10YR

32

10YR

21

CMOFMA

BSH

AFR

STP

Lmdash

Bss1

29ndash4

8GS

10YR

44

10YR

34

CSTV

CAB

EHAE

FIV

STV

PLmdash

Bss2

48ndash105

GS

10YR

36

10YR

32

CSTE

CAB

EHAE

FIV

STV

PLmdash

BCss

105ndash150+

mdash25Y

61

25Y

51

CSTE

CPR

EHAE

FIV

STV

PLmdash

1CS

=cle

arandsm

oothG

S=gradualand

smoo

th

2CL

=cla

yloam

C=cla

y3WE=weakST

=str

ongMO

=mod

erateVS

T=very

stron

gFI

=fin

eFM

=fin

eandmediumV

M=very

fineto

mediumM

C=medium

andcoarseM

E=mediumC

O=coarseV

C=very

coarseE

C=

extre

mely

coarseG

R=granularSB=subang

ular

blockyA

B=angularb

lockyPR

=prism

atic

4SH

A=slightly

hardV

HA=very

hardH

A=hardE

HA=extre

mely


stickyVS

T=very

stickyPL

=plasticSPL

=slightly

plasticV

PL=very

plasticFR=friableFI

=firmE

FI=extre

mely

firm




A-1


A-2


A-3


A-4


A-5



A-7












) AWC(volume )

FC PWP

A-1


A-2


A-3


A-4


A-5


A-6 Ap 0ndash20 120 253 5257 35 19 16

A-7























A-1


A-2


A-3


A-4


A-5


A-6 Ap 0ndash20 71 64 07 024 039

A-7










A-1


A-2


A-3


A-4


A-5


A-6 Ap 0ndash20 259 023 11 10832 755

A-7




minus1












minus1


A-1


A-2


A-3


A-4


A-5


A-6 0ndash20 1281 376 193 011 1861 2066 6261 05 341 90

A-7












A-1


A-2


A-3


A-4


A-5


A-6 Ap 0ndash20 1926 3400 473 357

A-7








Table10C

orrelatio

nmatrix



fAbo

boarea

Sand

Silt

Clay

120588 119887TP

AWC

pHOM

TNAv

PCa

Mg

CEC

FeMn

ZnCU

Sand

100

Silt

031

100

Clayminus0



100

120588 119887015

002

minus010

100

TPminus0

28014

007minus0


100

AWCminus0

31011

011

minus060lowast

061lowast

100

pH024

015

minus024

021

minus021

007

100

OM

025

057lowastminus0

52lowastminus0

35033

019

007

100

TN034

053lowastminus0

55lowastminus0

33030

014

013


100

AvP

012

047

minus038

minus011

019

019

05lowast

071lowastlowast

071lowastlowast

100

Ca021

032

009

minus011

minus020

006

021

008

minus002minus0

1410

0Mg

006

065lowastminus0

46minus0

31039

018minus0


075lowastlowast

046minus0

2510

0CE

Cminus0

06minus0

51lowast

037

minus009

minus020minus0

07minus0

12minus0

002

001minus0


1710

0Fe

011

043

minus035

minus036

038

006minus0

44057lowast

059lowast

007minus0


0510

0Mn

006

065lowastminus0

46minus0

31039

018minus0


075lowastlowast

063lowastminus0

25043minus0

17068lowastlowast

100

Zn002

051lowastminus0

35minus0

50lowast

059lowast

038

031

057lowast

055lowast

063lowastminus0

24058lowastminus0

44032

058lowast

100

CUminus0

36033

minus001minus0

63lowast


055minus0

23026

020

0200minus0

35040minus0

39036

040

058lowast

100

lowastSign

ificant


120588 119887=bu

lkdensity

TP=totalp

orosity

AWC=availablew

ater

contentOM

=organicm

atterTN

=totaln

itrogenA

vP=availablep

hospho

rusCE

C=catio

nexchange

capacity


N

0 3100 6200 93001550(Kms)


Vertic LuvisolsLake

8∘299840030

998400998400N

8∘09984000998400998400N

7∘57

99840030

998400998400N

7∘55

9984000998400998400N

7∘52

99840030

998400998400N

7∘50

9984000998400998400N

7∘47

99840030

998400998400N

8∘299840030

998400998400N

8∘09984000998400998400N

7∘57

99840030

998400998400N

7∘55

9984000998400998400N

7∘52

99840030

998400998400N

7∘50

9984000998400998400N

7∘47

99840030

998400998400N

34∘27

99840030

998400998400E 34∘30

9984000998400998400E 34

∘32

99840030

998400998400E 34∘35

9984000998400998400E 34

∘37

99840030

998400998400E

34∘27

99840030

998400998400E 34∘30

9984000998400998400E 34

∘32

99840030

998400998400E 34∘35

9984000998400998400E 34

∘37

99840030

998400998400E
















4 Conclusion



Competing Interests


Acknowledgments


References






































































Journal of












Volume 2014

Advances in









Geophysics















Table2Selected

morph

ologicalprop

ertie

softhe

pedo

ns

Pedo

nHorizon

Depth

(cm)

Boun

dary1

Color

Texture

(Feelm

etho

d)2

Structure3

Con

sistency4

Coarsefragm

ent()

Dry

Moist

A-1

Ap0ndash

18GS

10YR

36

10YR

33

CLMOV

MG

RSH

AFR

STSPL

mdashBw

118ndash25

GS

25Y

R46

25Y

R44

CLMOV

MA

BSH

AFR

STSPL

mdashBw

225ndash35

GS

25Y

R48

25Y

R46

CMOFMA

BSH

AFR

STP

Lmdash

CB35ndash110

mdash25Y

R46

25Y

R46

CMOFMA

BSH

AFR

STP

L47

A-2

A0ndash

18GS

10YR

43

10YR

32

CLMOFMG

RSH

RFR

STPL

mdashAd

18ndash27

CS10YR

43

10YR

32

CLMOFMA

BSH

AFR

STP

Lmdash

Bt1

27ndash37

CS25Y

R44

25Y

R43

CMOM

EAB

SHAFR

STP

Lmdash

Bt2

37ndash50

GS

25Y

R46

25Y

R45

CMOM

EAB

SHAFR

STP

Lmdash

BC50ndash80

mdash25Y

R46

25Y

R45

CMOM

EAB

SHAFR

STP

L21

A-3

Ap0ndash

22CS

75YR

33

75YR

33

CLMOFMG

RSH

AFR

STP

Lmdash

A22ndash33

CS75

YR33

75YR

32

CMOM

EAB

HAFR

VSTVPL

mdashBt1

33ndash4

5GS

5YR46

5YR44

CMOM

EAB

HAFR

VSTVPL

mdashBt2

45ndash6

3GS

5YR44

25Y

R43

CMOM

EAB

HAFR

VSTVPL

mdashBC

63ndash85

mdash5Y

R46

5YR44

CMOM

EAB

HAFR

VSTVPL

19

A-4

Ap0ndash

10CS

10YR

36

10YR

33

CLWE

FIG

RSH

AFR

STP

Lmdash

A10ndash19

CS10YR

34

10YR

33

CSTFMSB

VHAFISTP

Lmdash

Bt1

19ndash37

GS

75YR

44

75YR

33

CSTFMA

BVHAFISTP

Lmdash

Bt2

37ndash75

GS

5YR46

5YR34

CSTFMA

BHAFISTP

Lmdash

BC75ndash85

mdash5Y

R46

5YR44

CSTFMA

BSH

AFR

TSP

L23

A-5

Ap0ndash

17GS

10YR

37

10YR

31

CMOM

CAB

HAFR

STP

Lmdash

A17ndash55

GS

10YR

52

10YR

32

CSTC

OA

BVHAFISTP

Lmdash

Bss1

55ndash116

GS

25Y

52

25Y

42

CSTC

OA

BVHAV

FISTPL

mdashBC

ss2

116ndash

150

mdash10YR

52

10YR

32

CVS

TCO

AB

VHAV

FISTPL

mdashA-

6Ap

0ndash20

mdash10YR

43

10YR

32

LMOFMG

RSH

AFR

STP

Lmdash

A-7

A0ndash

29CS

10YR

32

10YR

21

CMOFMA

BSH

AFR

STP

Lmdash

Bss1

29ndash4

8GS

10YR

44

10YR

34

CSTV

CAB

EHAE

FIV

STV

PLmdash

Bss2

48ndash105

GS

10YR

36

10YR

32

CSTE

CAB

EHAE

FIV

STV

PLmdash

BCss

105ndash150+

mdash25Y

61

25Y

51

CSTE

CPR

EHAE

FIV

STV

PLmdash

1CS

=cle

arandsm

oothG

S=gradualand

smoo

th

2CL

=cla

yloam

C=cla

y3WE=weakST

=str

ongMO

=mod

erateVS

T=very

stron

gFI

=fin

eFM

=fin

eandmediumV

M=very

fineto

mediumM

C=medium

andcoarseM

E=mediumC

O=coarseV

C=very

coarseE

C=

extre

mely

coarseG

R=granularSB=subang

ular

blockyA

B=angularb

lockyPR

=prism

atic

4SH

A=slightly

hardV

HA=very

hardH

A=hardE

HA=extre

mely


stickyVS

T=very

stickyPL

=plasticSPL

=slightly

plasticV

PL=very

plasticFR=friableFI

=firmE

FI=extre

mely

firm




A-1


A-2


A-3


A-4


A-5



A-7












) AWC(volume )

FC PWP

A-1


A-2


A-3


A-4


A-5


A-6 Ap 0ndash20 120 253 5257 35 19 16

A-7























A-1


A-2


A-3


A-4


A-5


A-6 Ap 0ndash20 71 64 07 024 039

A-7










A-1


A-2


A-3


A-4


A-5


A-6 Ap 0ndash20 259 023 11 10832 755

A-7




minus1












minus1


A-1


A-2


A-3


A-4


A-5


A-6 0ndash20 1281 376 193 011 1861 2066 6261 05 341 90

A-7












A-1


A-2


A-3


A-4


A-5


A-6 Ap 0ndash20 1926 3400 473 357

A-7








Table10C

orrelatio

nmatrix



fAbo

boarea

Sand

Silt

Clay

120588 119887TP

AWC

pHOM

TNAv

PCa

Mg

CEC

FeMn

ZnCU

Sand

100

Silt

031

100

Clayminus0



100

120588 119887015

002

minus010

100

TPminus0

28014

007minus0


100

AWCminus0

31011

011

minus060lowast

061lowast

100

pH024

015

minus024

021

minus021

007

100

OM

025

057lowastminus0

52lowastminus0

35033

019

007

100

TN034

053lowastminus0

55lowastminus0

33030

014

013


100

AvP

012

047

minus038

minus011

019

019

05lowast

071lowastlowast

071lowastlowast

100

Ca021

032

009

minus011

minus020

006

021

008

minus002minus0

1410

0Mg

006

065lowastminus0

46minus0

31039

018minus0


075lowastlowast

046minus0

2510

0CE

Cminus0

06minus0

51lowast

037

minus009

minus020minus0

07minus0

12minus0

002

001minus0


1710

0Fe

011

043

minus035

minus036

038

006minus0

44057lowast

059lowast

007minus0


0510

0Mn

006

065lowastminus0

46minus0

31039

018minus0


075lowastlowast

063lowastminus0

25043minus0

17068lowastlowast

100

Zn002

051lowastminus0

35minus0

50lowast

059lowast

038

031

057lowast

055lowast

063lowastminus0

24058lowastminus0

44032

058lowast

100

CUminus0

36033

minus001minus0

63lowast


055minus0

23026

020

0200minus0

35040minus0

39036

040

058lowast

100

lowastSign

ificant


120588 119887=bu

lkdensity

TP=totalp

orosity

AWC=availablew

ater

contentOM

=organicm

atterTN

=totaln

itrogenA

vP=availablep

hospho

rusCE

C=catio

nexchange

capacity


N

0 3100 6200 93001550(Kms)


Vertic LuvisolsLake

8∘299840030

998400998400N

8∘09984000998400998400N

7∘57

99840030

998400998400N

7∘55

9984000998400998400N

7∘52

99840030

998400998400N

7∘50

9984000998400998400N

7∘47

99840030

998400998400N

8∘299840030

998400998400N

8∘09984000998400998400N

7∘57

99840030

998400998400N

7∘55

9984000998400998400N

7∘52

99840030

998400998400N

7∘50

9984000998400998400N

7∘47

99840030

998400998400N

34∘27

99840030

998400998400E 34∘30

9984000998400998400E 34

∘32

99840030

998400998400E 34∘35

9984000998400998400E 34

∘37

99840030

998400998400E

34∘27

99840030

998400998400E 34∘30

9984000998400998400E 34

∘32

99840030

998400998400E 34∘35

9984000998400998400E 34

∘37

99840030

998400998400E
















4 Conclusion



Competing Interests


Acknowledgments


References






































































Journal of












Volume 2014

Advances in









Geophysics

















A-1


A-2


A-3


A-4


A-5



A-7












) AWC(volume )

FC PWP

A-1


A-2


A-3


A-4


A-5


A-6 Ap 0ndash20 120 253 5257 35 19 16

A-7























A-1


A-2


A-3


A-4


A-5


A-6 Ap 0ndash20 71 64 07 024 039

A-7










A-1


A-2


A-3


A-4


A-5


A-6 Ap 0ndash20 259 023 11 10832 755

A-7




minus1












minus1


A-1


A-2


A-3


A-4


A-5


A-6 0ndash20 1281 376 193 011 1861 2066 6261 05 341 90

A-7












A-1


A-2


A-3


A-4


A-5


A-6 Ap 0ndash20 1926 3400 473 357

A-7








Table10C

orrelatio

nmatrix



fAbo

boarea

Sand

Silt

Clay

120588 119887TP

AWC

pHOM

TNAv

PCa

Mg

CEC

FeMn

ZnCU

Sand

100

Silt

031

100

Clayminus0



100

120588 119887015

002

minus010

100

TPminus0

28014

007minus0


100

AWCminus0

31011

011

minus060lowast

061lowast

100

pH024

015

minus024

021

minus021

007

100

OM

025

057lowastminus0

52lowastminus0

35033

019

007

100

TN034

053lowastminus0

55lowastminus0

33030

014

013


100

AvP

012

047

minus038

minus011

019

019

05lowast

071lowastlowast

071lowastlowast

100

Ca021

032

009

minus011

minus020

006

021

008

minus002minus0

1410

0Mg

006

065lowastminus0

46minus0

31039

018minus0


075lowastlowast

046minus0

2510

0CE

Cminus0

06minus0

51lowast

037

minus009

minus020minus0

07minus0

12minus0

002

001minus0


1710

0Fe

011

043

minus035

minus036

038

006minus0

44057lowast

059lowast

007minus0


0510

0Mn

006

065lowastminus0

46minus0

31039

018minus0


075lowastlowast

063lowastminus0

25043minus0

17068lowastlowast

100

Zn002

051lowastminus0

35minus0

50lowast

059lowast

038

031

057lowast

055lowast

063lowastminus0

24058lowastminus0

44032

058lowast

100

CUminus0

36033

minus001minus0

63lowast


055minus0

23026

020

0200minus0

35040minus0

39036

040

058lowast

100

lowastSign

ificant


120588 119887=bu

lkdensity

TP=totalp

orosity

AWC=availablew

ater

contentOM

=organicm

atterTN

=totaln

itrogenA

vP=availablep

hospho

rusCE

C=catio

nexchange

capacity


N

0 3100 6200 93001550(Kms)


Vertic LuvisolsLake

8∘299840030

998400998400N

8∘09984000998400998400N

7∘57

99840030

998400998400N

7∘55

9984000998400998400N

7∘52

99840030

998400998400N

7∘50

9984000998400998400N

7∘47

99840030

998400998400N

8∘299840030

998400998400N

8∘09984000998400998400N

7∘57

99840030

998400998400N

7∘55

9984000998400998400N

7∘52

99840030

998400998400N

7∘50

9984000998400998400N

7∘47

99840030

998400998400N

34∘27

99840030

998400998400E 34∘30

9984000998400998400E 34

∘32

99840030

998400998400E 34∘35

9984000998400998400E 34

∘37

99840030

998400998400E

34∘27

99840030

998400998400E 34∘30

9984000998400998400E 34

∘32

99840030

998400998400E 34∘35

9984000998400998400E 34

∘37

99840030

998400998400E
















4 Conclusion



Competing Interests


Acknowledgments


References






































































Journal of












Volume 2014

Advances in









Geophysics

















) AWC(volume )

FC PWP

A-1


A-2


A-3


A-4


A-5


A-6 Ap 0ndash20 120 253 5257 35 19 16

A-7























A-1


A-2


A-3


A-4


A-5


A-6 Ap 0ndash20 71 64 07 024 039

A-7










A-1


A-2


A-3


A-4


A-5


A-6 Ap 0ndash20 259 023 11 10832 755

A-7




minus1












minus1


A-1


A-2


A-3


A-4


A-5


A-6 0ndash20 1281 376 193 011 1861 2066 6261 05 341 90

A-7












A-1


A-2


A-3


A-4


A-5


A-6 Ap 0ndash20 1926 3400 473 357

A-7








Table10C

orrelatio

nmatrix



fAbo

boarea

Sand

Silt

Clay

120588 119887TP

AWC

pHOM

TNAv

PCa

Mg

CEC

FeMn

ZnCU

Sand

100

Silt

031

100

Clayminus0



100

120588 119887015

002

minus010

100

TPminus0

28014

007minus0


100

AWCminus0

31011

011

minus060lowast

061lowast

100

pH024

015

minus024

021

minus021

007

100

OM

025

057lowastminus0

52lowastminus0

35033

019

007

100

TN034

053lowastminus0

55lowastminus0

33030

014

013


100

AvP

012

047

minus038

minus011

019

019

05lowast

071lowastlowast

071lowastlowast

100

Ca021

032

009

minus011

minus020

006

021

008

minus002minus0

1410

0Mg

006

065lowastminus0

46minus0

31039

018minus0


075lowastlowast

046minus0

2510

0CE

Cminus0

06minus0

51lowast

037

minus009

minus020minus0

07minus0

12minus0

002

001minus0


1710

0Fe

011

043

minus035

minus036

038

006minus0

44057lowast

059lowast

007minus0


0510

0Mn

006

065lowastminus0

46minus0

31039

018minus0


075lowastlowast

063lowastminus0

25043minus0

17068lowastlowast

100

Zn002

051lowastminus0

35minus0

50lowast

059lowast

038

031

057lowast

055lowast

063lowastminus0

24058lowastminus0

44032

058lowast

100

CUminus0

36033

minus001minus0

63lowast


055minus0

23026

020

0200minus0

35040minus0

39036

040

058lowast

100

lowastSign

ificant


120588 119887=bu

lkdensity

TP=totalp

orosity

AWC=availablew

ater

contentOM

=organicm

atterTN

=totaln

itrogenA

vP=availablep

hospho

rusCE

C=catio

nexchange

capacity


N

0 3100 6200 93001550(Kms)


Vertic LuvisolsLake

8∘299840030

998400998400N

8∘09984000998400998400N

7∘57

99840030

998400998400N

7∘55

9984000998400998400N

7∘52

99840030

998400998400N

7∘50

9984000998400998400N

7∘47

99840030

998400998400N

8∘299840030

998400998400N

8∘09984000998400998400N

7∘57

99840030

998400998400N

7∘55

9984000998400998400N

7∘52

99840030

998400998400N

7∘50

9984000998400998400N

7∘47

99840030

998400998400N

34∘27

99840030

998400998400E 34∘30

9984000998400998400E 34

∘32

99840030

998400998400E 34∘35

9984000998400998400E 34

∘37

99840030

998400998400E

34∘27

99840030

998400998400E 34∘30

9984000998400998400E 34

∘32

99840030

998400998400E 34∘35

9984000998400998400E 34

∘37

99840030

998400998400E
















4 Conclusion



Competing Interests


Acknowledgments


References






































































Journal of












Volume 2014

Advances in









Geophysics






























A-1


A-2


A-3


A-4


A-5


A-6 Ap 0ndash20 71 64 07 024 039

A-7










A-1


A-2


A-3


A-4


A-5


A-6 Ap 0ndash20 259 023 11 10832 755

A-7




minus1












minus1


A-1


A-2


A-3


A-4


A-5


A-6 0ndash20 1281 376 193 011 1861 2066 6261 05 341 90

A-7












A-1


A-2


A-3


A-4


A-5


A-6 Ap 0ndash20 1926 3400 473 357

A-7








Table10C

orrelatio

nmatrix



fAbo

boarea

Sand

Silt

Clay

120588 119887TP

AWC

pHOM

TNAv

PCa

Mg

CEC

FeMn

ZnCU

Sand

100

Silt

031

100

Clayminus0



100

120588 119887015

002

minus010

100

TPminus0

28014

007minus0


100

AWCminus0

31011

011

minus060lowast

061lowast

100

pH024

015

minus024

021

minus021

007

100

OM

025

057lowastminus0

52lowastminus0

35033

019

007

100

TN034

053lowastminus0

55lowastminus0

33030

014

013


100

AvP

012

047

minus038

minus011

019

019

05lowast

071lowastlowast

071lowastlowast

100

Ca021

032

009

minus011

minus020

006

021

008

minus002minus0

1410

0Mg

006

065lowastminus0

46minus0

31039

018minus0


075lowastlowast

046minus0

2510

0CE

Cminus0

06minus0

51lowast

037

minus009

minus020minus0

07minus0

12minus0

002

001minus0


1710

0Fe

011

043

minus035

minus036

038

006minus0

44057lowast

059lowast

007minus0


0510

0Mn

006

065lowastminus0

46minus0

31039

018minus0


075lowastlowast

063lowastminus0

25043minus0

17068lowastlowast

100

Zn002

051lowastminus0

35minus0

50lowast

059lowast

038

031

057lowast

055lowast

063lowastminus0

24058lowastminus0

44032

058lowast

100

CUminus0

36033

minus001minus0

63lowast


055minus0

23026

020

0200minus0

35040minus0

39036

040

058lowast

100

lowastSign

ificant


120588 119887=bu

lkdensity

TP=totalp

orosity

AWC=availablew

ater

contentOM

=organicm

atterTN

=totaln

itrogenA

vP=availablep

hospho

rusCE

C=catio

nexchange

capacity


N

0 3100 6200 93001550(Kms)


Vertic LuvisolsLake

8∘299840030

998400998400N

8∘09984000998400998400N

7∘57

99840030

998400998400N

7∘55

9984000998400998400N

7∘52

99840030

998400998400N

7∘50

9984000998400998400N

7∘47

99840030

998400998400N

8∘299840030

998400998400N

8∘09984000998400998400N

7∘57

99840030

998400998400N

7∘55

9984000998400998400N

7∘52

99840030

998400998400N

7∘50

9984000998400998400N

7∘47

99840030

998400998400N

34∘27

99840030

998400998400E 34∘30

9984000998400998400E 34

∘32

99840030

998400998400E 34∘35

9984000998400998400E 34

∘37

99840030

998400998400E

34∘27

99840030

998400998400E 34∘30

9984000998400998400E 34

∘32

99840030

998400998400E 34∘35

9984000998400998400E 34

∘37

99840030

998400998400E
















4 Conclusion



Competing Interests


Acknowledgments


References






































































Journal of












Volume 2014

Advances in









Geophysics

















A-1


A-2


A-3


A-4


A-5


A-6 Ap 0ndash20 259 023 11 10832 755

A-7




minus1












minus1


A-1


A-2


A-3


A-4


A-5


A-6 0ndash20 1281 376 193 011 1861 2066 6261 05 341 90

A-7












A-1


A-2


A-3


A-4


A-5


A-6 Ap 0ndash20 1926 3400 473 357

A-7








Table10C

orrelatio

nmatrix



fAbo

boarea

Sand

Silt

Clay

120588 119887TP

AWC

pHOM

TNAv

PCa

Mg

CEC

FeMn

ZnCU

Sand

100

Silt

031

100

Clayminus0



100

120588 119887015

002

minus010

100

TPminus0

28014

007minus0


100

AWCminus0

31011

011

minus060lowast

061lowast

100

pH024

015

minus024

021

minus021

007

100

OM

025

057lowastminus0

52lowastminus0

35033

019

007

100

TN034

053lowastminus0

55lowastminus0

33030

014

013


100

AvP

012

047

minus038

minus011

019

019

05lowast

071lowastlowast

071lowastlowast

100

Ca021

032

009

minus011

minus020

006

021

008

minus002minus0

1410

0Mg

006

065lowastminus0

46minus0

31039

018minus0


075lowastlowast

046minus0

2510

0CE

Cminus0

06minus0

51lowast

037

minus009

minus020minus0

07minus0

12minus0

002

001minus0


1710

0Fe

011

043

minus035

minus036

038

006minus0

44057lowast

059lowast

007minus0


0510

0Mn

006

065lowastminus0

46minus0

31039

018minus0


075lowastlowast

063lowastminus0

25043minus0

17068lowastlowast

100

Zn002

051lowastminus0

35minus0

50lowast

059lowast

038

031

057lowast

055lowast

063lowastminus0

24058lowastminus0

44032

058lowast

100

CUminus0

36033

minus001minus0

63lowast


055minus0

23026

020

0200minus0

35040minus0

39036

040

058lowast

100

lowastSign

ificant


120588 119887=bu

lkdensity

TP=totalp

orosity

AWC=availablew

ater

contentOM

=organicm

atterTN

=totaln

itrogenA

vP=availablep

hospho

rusCE

C=catio

nexchange

capacity


N

0 3100 6200 93001550(Kms)


Vertic LuvisolsLake

8∘299840030

998400998400N

8∘09984000998400998400N

7∘57

99840030

998400998400N

7∘55

9984000998400998400N

7∘52

99840030

998400998400N

7∘50

9984000998400998400N

7∘47

99840030

998400998400N

8∘299840030

998400998400N

8∘09984000998400998400N

7∘57

99840030

998400998400N

7∘55

9984000998400998400N

7∘52

99840030

998400998400N

7∘50

9984000998400998400N

7∘47

99840030

998400998400N

34∘27

99840030

998400998400E 34∘30

9984000998400998400E 34

∘32

99840030

998400998400E 34∘35

9984000998400998400E 34

∘37

99840030

998400998400E

34∘27

99840030

998400998400E 34∘30

9984000998400998400E 34

∘32

99840030

998400998400E 34∘35

9984000998400998400E 34

∘37

99840030

998400998400E
















4 Conclusion



Competing Interests


Acknowledgments


References






































































Journal of












Volume 2014

Advances in









Geophysics

















minus1


A-1


A-2


A-3


A-4


A-5


A-6 0ndash20 1281 376 193 011 1861 2066 6261 05 341 90

A-7












A-1


A-2


A-3


A-4


A-5


A-6 Ap 0ndash20 1926 3400 473 357

A-7








Table10C

orrelatio

nmatrix



fAbo

boarea

Sand

Silt

Clay

120588 119887TP

AWC

pHOM

TNAv

PCa

Mg

CEC

FeMn

ZnCU

Sand

100

Silt

031

100

Clayminus0



100

120588 119887015

002

minus010

100

TPminus0

28014

007minus0


100

AWCminus0

31011

011

minus060lowast

061lowast

100

pH024

015

minus024

021

minus021

007

100

OM

025

057lowastminus0

52lowastminus0

35033

019

007

100

TN034

053lowastminus0

55lowastminus0

33030

014

013


100

AvP

012

047

minus038

minus011

019

019

05lowast

071lowastlowast

071lowastlowast

100

Ca021

032

009

minus011

minus020

006

021

008

minus002minus0

1410

0Mg

006

065lowastminus0

46minus0

31039

018minus0


075lowastlowast

046minus0

2510

0CE

Cminus0

06minus0

51lowast

037

minus009

minus020minus0

07minus0

12minus0

002

001minus0


1710

0Fe

011

043

minus035

minus036

038

006minus0

44057lowast

059lowast

007minus0


0510

0Mn

006

065lowastminus0

46minus0

31039

018minus0


075lowastlowast

063lowastminus0

25043minus0

17068lowastlowast

100

Zn002

051lowastminus0

35minus0

50lowast

059lowast

038

031

057lowast

055lowast

063lowastminus0

24058lowastminus0

44032

058lowast

100

CUminus0

36033

minus001minus0

63lowast


055minus0

23026

020

0200minus0

35040minus0

39036

040

058lowast

100

lowastSign

ificant


120588 119887=bu

lkdensity

TP=totalp

orosity

AWC=availablew

ater

contentOM

=organicm

atterTN

=totaln

itrogenA

vP=availablep

hospho

rusCE

C=catio

nexchange

capacity


N

0 3100 6200 93001550(Kms)


Vertic LuvisolsLake

8∘299840030

998400998400N

8∘09984000998400998400N

7∘57

99840030

998400998400N

7∘55

9984000998400998400N

7∘52

99840030

998400998400N

7∘50

9984000998400998400N

7∘47

99840030

998400998400N

8∘299840030

998400998400N

8∘09984000998400998400N

7∘57

99840030

998400998400N

7∘55

9984000998400998400N

7∘52

99840030

998400998400N

7∘50

9984000998400998400N

7∘47

99840030

998400998400N

34∘27

99840030

998400998400E 34∘30

9984000998400998400E 34

∘32

99840030

998400998400E 34∘35

9984000998400998400E 34

∘37

99840030

998400998400E

34∘27

99840030

998400998400E 34∘30

9984000998400998400E 34

∘32

99840030

998400998400E 34∘35

9984000998400998400E 34

∘37

99840030

998400998400E
















4 Conclusion



Competing Interests


Acknowledgments


References






































































Journal of












Volume 2014

Advances in









Geophysics

















A-1


A-2


A-3


A-4


A-5


A-6 Ap 0ndash20 1926 3400 473 357

A-7








Table10C

orrelatio

nmatrix



fAbo

boarea

Sand

Silt

Clay

120588 119887TP

AWC

pHOM

TNAv

PCa

Mg

CEC

FeMn

ZnCU

Sand

100

Silt

031

100

Clayminus0



100

120588 119887015

002

minus010

100

TPminus0

28014

007minus0


100

AWCminus0

31011

011

minus060lowast

061lowast

100

pH024

015

minus024

021

minus021

007

100

OM

025

057lowastminus0

52lowastminus0

35033

019

007

100

TN034

053lowastminus0

55lowastminus0

33030

014

013


100

AvP

012

047

minus038

minus011

019

019

05lowast

071lowastlowast

071lowastlowast

100

Ca021

032

009

minus011

minus020

006

021

008

minus002minus0

1410

0Mg

006

065lowastminus0

46minus0

31039

018minus0


075lowastlowast

046minus0

2510

0CE

Cminus0

06minus0

51lowast

037

minus009

minus020minus0

07minus0

12minus0

002

001minus0


1710

0Fe

011

043

minus035

minus036

038

006minus0

44057lowast

059lowast

007minus0


0510

0Mn

006

065lowastminus0

46minus0

31039

018minus0


075lowastlowast

063lowastminus0

25043minus0

17068lowastlowast

100

Zn002

051lowastminus0

35minus0

50lowast

059lowast

038

031

057lowast

055lowast

063lowastminus0

24058lowastminus0

44032

058lowast

100

CUminus0

36033

minus001minus0

63lowast


055minus0

23026

020

0200minus0

35040minus0

39036

040

058lowast

100

lowastSign

ificant


120588 119887=bu

lkdensity

TP=totalp

orosity

AWC=availablew

ater

contentOM

=organicm

atterTN

=totaln

itrogenA

vP=availablep

hospho

rusCE

C=catio

nexchange

capacity


N

0 3100 6200 93001550(Kms)


Vertic LuvisolsLake

8∘299840030

998400998400N

8∘09984000998400998400N

7∘57

99840030

998400998400N

7∘55

9984000998400998400N

7∘52

99840030

998400998400N

7∘50

9984000998400998400N

7∘47

99840030

998400998400N

8∘299840030

998400998400N

8∘09984000998400998400N

7∘57

99840030

998400998400N

7∘55

9984000998400998400N

7∘52

99840030

998400998400N

7∘50

9984000998400998400N

7∘47

99840030

998400998400N

34∘27

99840030

998400998400E 34∘30

9984000998400998400E 34

∘32

99840030

998400998400E 34∘35

9984000998400998400E 34

∘37

99840030

998400998400E

34∘27

99840030

998400998400E 34∘30

9984000998400998400E 34

∘32

99840030

998400998400E 34∘35

9984000998400998400E 34

∘37

99840030

998400998400E
















4 Conclusion



Competing Interests


Acknowledgments


References






































































Journal of












Volume 2014

Advances in









Geophysics















Table10C

orrelatio

nmatrix



fAbo

boarea

Sand

Silt

Clay

120588 119887TP

AWC

pHOM

TNAv

PCa

Mg

CEC

FeMn

ZnCU

Sand

100

Silt

031

100

Clayminus0



100

120588 119887015

002

minus010

100

TPminus0

28014

007minus0


100

AWCminus0

31011

011

minus060lowast

061lowast

100

pH024

015

minus024

021

minus021

007

100

OM

025

057lowastminus0

52lowastminus0

35033

019

007

100

TN034

053lowastminus0

55lowastminus0

33030

014

013


100

AvP

012

047

minus038

minus011

019

019

05lowast

071lowastlowast

071lowastlowast

100

Ca021

032

009

minus011

minus020

006

021

008

minus002minus0

1410

0Mg

006

065lowastminus0

46minus0

31039

018minus0


075lowastlowast

046minus0

2510

0CE

Cminus0

06minus0

51lowast

037

minus009

minus020minus0

07minus0

12minus0

002

001minus0


1710

0Fe

011

043

minus035

minus036

038

006minus0

44057lowast

059lowast

007minus0


0510

0Mn

006

065lowastminus0

46minus0

31039

018minus0


075lowastlowast

063lowastminus0

25043minus0

17068lowastlowast

100

Zn002

051lowastminus0

35minus0

50lowast

059lowast

038

031

057lowast

055lowast

063lowastminus0

24058lowastminus0

44032

058lowast

100

CUminus0

36033

minus001minus0

63lowast


055minus0

23026

020

0200minus0

35040minus0

39036

040

058lowast

100

lowastSign

ificant


120588 119887=bu

lkdensity

TP=totalp

orosity

AWC=availablew

ater

contentOM

=organicm

atterTN

=totaln

itrogenA

vP=availablep

hospho

rusCE

C=catio

nexchange

capacity


N

0 3100 6200 93001550(Kms)


Vertic LuvisolsLake

8∘299840030

998400998400N

8∘09984000998400998400N

7∘57

99840030

998400998400N

7∘55

9984000998400998400N

7∘52

99840030

998400998400N

7∘50

9984000998400998400N

7∘47

99840030

998400998400N

8∘299840030

998400998400N

8∘09984000998400998400N

7∘57

99840030

998400998400N

7∘55

9984000998400998400N

7∘52

99840030

998400998400N

7∘50

9984000998400998400N

7∘47

99840030

998400998400N

34∘27

99840030

998400998400E 34∘30

9984000998400998400E 34

∘32

99840030

998400998400E 34∘35

9984000998400998400E 34

∘37

99840030

998400998400E

34∘27

99840030

998400998400E 34∘30

9984000998400998400E 34

∘32

99840030

998400998400E 34∘35

9984000998400998400E 34

∘37

99840030

998400998400E
















4 Conclusion



Competing Interests


Acknowledgments


References






































































Journal of












Volume 2014

Advances in









Geophysics















N

0 3100 6200 93001550(Kms)


Vertic LuvisolsLake

8∘299840030

998400998400N

8∘09984000998400998400N

7∘57

99840030

998400998400N

7∘55

9984000998400998400N

7∘52

99840030

998400998400N

7∘50

9984000998400998400N

7∘47

99840030

998400998400N

8∘299840030

998400998400N

8∘09984000998400998400N

7∘57

99840030

998400998400N

7∘55

9984000998400998400N

7∘52

99840030

998400998400N

7∘50

9984000998400998400N

7∘47

99840030

998400998400N

34∘27

99840030

998400998400E 34∘30

9984000998400998400E 34

∘32

99840030

998400998400E 34∘35

9984000998400998400E 34

∘37

99840030

998400998400E

34∘27

99840030

998400998400E 34∘30

9984000998400998400E 34

∘32

99840030

998400998400E 34∘35

9984000998400998400E 34

∘37

99840030

998400998400E
















4 Conclusion



Competing Interests


Acknowledgments


References






































































Journal of












Volume 2014

Advances in









Geophysics






















4 Conclusion



Competing Interests


Acknowledgments


References






































































Journal of












Volume 2014

Advances in









Geophysics


















































































Journal of












Volume 2014

Advances in









Geophysics














characterization and classification of soils of abobo area, western

Documents