UNIVERSITI PUTRA MALAYSIA

THE EFFECTS OF DOLOMITIC LIMESTONE AND GYPSUM ON CHEMICAL PROPERTIES OF AN ULTISOL AND OXISOL IN

MALAYSIA AND ON THE GROWTH OF CORN (ZEA MAYS L.)

ISMAIL BIN HASHIM

FPP 1992 1

THE EFFECTS OF DOLOMITIC LIMESTONE AND GYPSUM ON CHEMICAL PROPERTIES OF AN ULTISOL AND OXISOL IN MALAYSIA

AND ON THE GROWTH OF CORN (Zea mays L . )

by

Ismail bin Hashim

Thesis Submitted in Fulfil lment of the Requirements for the Degree of Master in Agricultural Science

in the Faculty of Agriculture , Universiti Pertanian Malays ia , Serdang , Selangor Darul Ehsan .

July 1992

ACKNOWLEDGEMENTS

The author would like to express his profound

gratitude and appreciation to the fol lowing people for

their invaluable contributions in the completion of this

dissertation :

My chairman , Associate Professor Dr . Shamshuddin

Jusop , for his constant encouragement , guidance and

valuable comments in completing of the thesis ;

To my committee members , Tuan Haj i Syed Omar Syed

Rastan and Dr . Hamdan Suhaimi , for their understanding and

constructive criticism and also for being members of the

graduate committee ;

Tuan Haj i Ahmad and his assistants at MARDI for help

in the analysis using Inductively Coupled Plasma Emiss ion

Atomic Spectrophotometer ;

The members of Soil Mineralogy Analyses Laboratory ,

Department of Soi l Science , UPM , especially Azal i ,

Jamilah , Mas and khuzaimah , who have directly or

indirectly contributed to the success of this thesis ; and

My wife , my son , and members of my family for their

continued encouragement , moral and f inancial support

throughout the study .

ii

TABLE OF CONTENTS

ACKNOWLEDGEMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

LIST OF TABLES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

LIST OF FIGURES

LIST OF ABBREVIATIONS

ABSTRACT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

ABSTRAK

CHAPTER

I INTRODUCTION

I I REVIEW OF LITERATURE

Parent Materials

Weathering

Mineralogy

Chemical Properties

Charge Properties

Soil pH

Exchangeable AI , Ca and Mg

Soil Solution Composition

Soils in Malaysia

Effects of Limestone on Ultisols

Page

i i

vi

vi i i

x

xi

xiv

1

4

6

7

12

12

13

1 5

1 6

1 6

and Oxisols . . . . . . . . . . . . . . . . . . . . . . . . 19

Effects of Gypsum on Ultisols and Oxisols . . . . . . . . . . . . . . . . . . . . . . . . 2 1

Growth of Corn on Ultisols and Oxisols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 2

The Need for Further Work . . . . . . . . . . 2 4

iii

I I I MATERIALS AND METHODS

Soil Sampling

Chemical Analyses . . . . . . . . . . . . . . . . .

Mineralogical Analysis

Charge Characterization

Leaching Experiments

Soil Columns

Experimental

Soil Solution Extraction and Al

Page

2 6

2 6

2 9

3 0

3 1

3 3

Speciation . . . . . . . . • • . . • • . . . . . • . 3 4

Pot Trials

Experimental 3 4

Soil and Soil Solution Analysis . . . . . . . . . . . . . . . . . . . . . . . 3 5

Tissue Analysis

IV RESULTS AND DISCUSSION

untreated Soils

Chemical properties and

3 6

Mineralogy . . . . . . . . . . . . . . . . . . . . . 3 7

Charge Characteristics

Effects of Limestone and Gypsum on Chemical Properties of Bungor and

3 9

Prang Series . . . . . . . . • • . . . . . . • . . . . . 4 3

Changes in Charge and Chemical properties

Effects of GML

Effects of Gypsum

Movement of Ions in Soils

iv

4 6

4 7

5 2

Page

Properties of Leachate

pH 5 5

Electrical Conductivity 5 6

Nitrate and Sulfate 5 8

Calcium , Magnesi um and Aluminium . . . . . . . . . . . . . . . . . . . 58

Soil Solution Properties 6 1

Effects of GML and Gypsum on Corn 67

v CONCLUSION 7 9

BIBLIOGRAPHY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 2

BIOGRAPHICAL SKETCH 8 9

v

LIST OF TABLES

Table

1 Quantitative Distribution of Kaol inite G ibbs ite , Fe203 , Mica/Chlorite and Sand + s i lt in Highly Weathered Malaysian

Page

Soils . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1

2 Quantitative Distribution of Kaolinite Gibbsite , Goethite and Mica/ Chlorite in Clay Fraction of B Horizon of Highly Weathered Malaysian Soils . . . • • . . . . . • . . . 17

3 Soi ls Ser ies for preliminary Study and Charge Characterization • • • . . . . . . . . • 2 7

4 Elemental Composition of Limestone and Gypsum . . . . . . . . . . . . . . . . • . . . . . . • . . . . . 3 3

5 Relationship Between CECT, CECB and AEC of Bungor and Prang Series Soils and pH 4 2

6 Selected Chemical Properties of the Top Soils ( 0- 15 cm) and Subsoils ( 4 5 - 6 0 cm) of Bungor and Prang Series • • . . . . . • . . . . 4 5

7 Effects of Gypsum Application on pH of Top soil ( 0-15 cm) of Bungor and Prang Series . . . . . . . . . . . . . . . . . . . . . . . . . . 4 7

8 Effects of S04 adsorption on Soil pH , Negative Charge and Ca Adsorption in Top Soil ( 0-15 cm) of Prang Series ( P < 0 . 0 1 ) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 8

9 Effects of GML and Gypsum on Exchangeable Ca and Al in the Soi l of Bungor Series 5 3

1 0 Changes i n Extractable S04 and N03 with Depth in the Prang Series Soil by Gypsum Application . . . . . . . . . • . . . . . . . . 55

1 1 Effects of GML and Gypsum on pH , EC , S04 and N03 in the Leachates of Bungor and Prang Series Soils . . . . . . . . . . • . . . . . . 5 7

1 2 Effects o f GML and Gypsum on Concentration of Ca , Mg and Al in the Leachates of Bungor and Prang Series Soils . . . . . . . . . . . . . . . . . 5 9

vi

Table

1 3

1 4

1 5

1 6

Chemical Properties o f Soil Solution in the Top Soil ( 0-15 cm) of Bungor and Prang Series Soils as Affected by GML and Gypsum Application . . . . . . . . . . . . .

Effect of GML and Gypsum Applications on pH and Activity of Ions in the Soil Solution of Bungor and Prang Series Soils ( 0-15 em) . . . . . . . . . . . . . . . . . . . . . . .

Changes in Soil Solution Chemical Properties of Bungor and Prang Series with Depth as Affected by GML and Gypsum Applications . . . . . . . . . . . . . . . . . . .

Effects of GML and Gypsum on pH , EC and Corn Growth . . . . . . . . . . . . . . . . . . . . . . .

vii

Page

6 2

6 5

6 6

6 8

LIST OF FIGURES

Figure

1

2

3

4

5

6

7

8

9

1 0

1 1

1 2

1 3

1 4

Rock Type Distribution i n Peninsular Malaysia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

X-ray Diffractograms of the Clay Fraction ( B2 t ) in Kuala Brang Series Soil . . . • . .

X-ray Diffractograms of the Clay Fraction in Rengam Series Soi l . . . . . . . . . • . . . . . . .

X-ray Diffractograms of the Clay Fraction in Kuantan Series Soi l . . . . . . . . . . . . . • . . .

Charge Development on the Surface of Mineral Hydroxides . . . . . . . . . . . . • . . . . . . . .

D iagrammatic Representation of Soil Profi le Reconstructed in a PVC Column

X-ray Diffractograms of the Clay Fraction in Ul tisols . . . . . . . . . . . . . . . . . . . . . . . . . . . .

X-ray D iffractograms of the Clay Fraction in oxisols . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Changes in the pH , CECT , CECB and AEC in the Top Soil of Bungor and Prang Ser ies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Grouping Soils into Type 1 , 2 and 3 on the Basis of charge Character istics

Effects of Gypsum Application on Negative Charge of Soils of Bungor and Prang Ser ies . . . . . . . . . . . . . . . . . . . . . . . . . . .

I l l ustration of Negative Charge Development by S04 Adsorption

Relationship Between Al in the Leaf (A) and Relative Top Corn Weight (B) and Soil Solution Al Concentration . . . . . . . . .

Relationship Between Ca in the Leaf (A) and Relative Top Corn Weight (B) and Soil Solution Ca Concentration . . . . . . . . .

vi i i

Page

5

8

9

1 0

1 4

3 2

3 8

4 0

4 1

4 4

5 0

5 1

7 0

7 2

Figure

1 5

1 6

1 7

1 8

Relationship Between Relative Top Corn Weight and Soil Solution Ca/AI Ratio

Relationship Between Al (A) and Mn ( B ) Concentration in the Soi l Solution of B ungor and Prang Series and pH

Relationship Between Mg in the Leaf (A) and Relative Top Corn Weight (B) and Soil Solution Mg Concentration . . • . . . . .

Relationship Between Top Corn Weight and Exchangeable Mg . . . . . . . . . . . . . . . . . . . •

ix

Page

7 3

7 6

7 7

7 8

GML

CEC

ECEC

kPa

PVC

ICPEAS

*

LIST OF ABBREVIATIONS

Ground Oolomitie Limestone

': cation Exchange Capacity

Effective Cation Exchange Capacity

Kilo Pascal

Polyvinylchloride

Inductively Coupled Plasma Emission Atomic Spectrophotometer

: Total cation Exchange Capacity*

: Bas ic cation Exchange capacity*

Anion Exchange capacity*

MicroSiemens per centimeter

as def ined by Gil lman and Sumpter ( 19 8 6 )

x

Abstract of the thesis submitted to the Senate of Universiti Pertanian Malaysia in fulfi lment of the requirement for the degree of Master of Agricultural Science.

THE EFFECTS OF DOLOMITIC LIMESTONE AND GYPSUM ON CHEMICAL PROPERTIES OF AN ULTISOL AND OXISOL IN MALAYSIA AND

ON THE GROWTH OF CORN ( Zea mays L . )

by

Ismai l Bin Hashim

July 1992

Cha irman Associate Prof . Dr . Shamshuddin Jusop

Faculty Agriculture

Ultisols and Oxisols are acidic in nature , with low

CEC, low exchangeable bases , and high Al saturation , and

are dominated by variable-charged minerals . The soi ls need

to be amel iorated before they can be uti l i z ed

productively . This study was conducted to determine the

reactions taking place in the soils as affected by

l imestone and gypsum appl ications and to assess the

effects of these changes on the growth of corn .

Based on mineralogy , charge and texture , two soi ls

were selected for investigation in the glasshouse . These

soi ls were Bungor (Ultisol ) and Prang series ( Oxisol ) . In

experiment 1 , the soi ls were repacked into PVC leaching

columns to a depth of 9 0 cm . Ground magnesium l imestone

( GML) , gypsum and their combinations were incorporated

xi

into the soils at 0-5 cm depth , and were s ubj ected to

leaching environments for 6 months . In experiment 2 , the

soils were mixed with GML , gypsum and their combinations

as a precursor to a glasshouse trial to asses the response

of corn to the amel iorants . The trial involved

equil ibrating the amel iorants and basal nutrients for 3 0

days prior to the corn growth for 4 0 days .

The results showed that the Ul tisols and Oxisols

differed in their mineralogy and charge properties . The

Ultisols contained mainly kaolinite , whi le the Oxisols

contained kaolinite , gibbsite , and goethite . The chemical

properties of these three minerals were affected by the

appl ication of l imestone and gypsum .

GML application increased soil pH , resulting i n an

increase in negati ve charge on clay surfaces . Thi s

explain the retention of Ca i n the z one o f GML

incorporation . In the gypsum treated soi ls , Ca moved

deeper into the profile , ameliorating Ca def iciency in the

s ubsoi l . The study indicates that GML application i n

combination with gypsum help al leviate A l toxicity in t he

top soil and Ca and/or Mg def iciency in the s ubsoi l .

S ul fate from the gypsum was adsorbed on the oxides of

Fe and/ or AI . The adsorption of so/- resul ted in an

increase in negative charge and soi l pH . This phenomenon

was we ll manifested in the Oxisol due to the presence h igh

xii

amount of oxides . Data from soi l solutions and leachates

showed that gypsum appl ication resulted in precipitation

of alunite and/ or j urbanite .

Corn can be grown on Ultisol and Oxisol in Malaysia

if the soils are treated by GML in combination with gyps um

at a suitable rate . It was found that 2 t GML applied

together with 1-2 t gypsum ha- 1 yielded near maximal top

corn weight . At this rate of application , soi l solution

pH increased from 4 . 0 to about 5 . 3 , with a consequent

reduction in Al and Mn concentrations to about 2 0 and 6

�M , respectively . It was observed that Al concentration

in the soil solution was positively correlated with the

amount of Al in the leaf , but negatively correlated with

relat ive top corn weight . S imi larly , Ca and Mg in the

soil solut ions were positively correlated with Ca and Mg

in the leaf . It was observed that Mg in the soi l solution

was positively correlated with relative top corn weight .

Thi s study shows that AI , Ca and Mg concentrations , and

Ca/AI concentration ratio in the soi l solution can be used

as indices of soil acidity .

xi i i

Abstrak tesis yang dikemukakan kepada Senat universiti Pertanian Malaysia sebagai memenuhi keperluan untuk mendapatkan Ij azah Master Sains Pertanian .

KESAN BATUKAPUR DOLOMIT DAN GIPSUM KE ATAS S IFAT KIMIA TANAH ULTISOL DAN OKSISOL DI MALAYSIA DAN KESANNYA

KE ATAS PERTUMBUHAN JAGUNG ( Zea mays L . )

Oleh

Ismail Bin Hashim

Julai 1992

Pengerus i Profesor Madya Dr . Shamshuddin Jusop

Fakulti Pertanian

Ultisol dan Oksisol adalah tanah berasid , mempunya i

KPK , bes bertukarganti yang rendah sementara t inggi

ketepuan Al dan mengandungi mineral muatan berubah .

Tanah-tanah ini perlu diperbaiki sebelum ianya boleh

digunakan untuk pertanian . Penyelidikan telah dij alankan

untuk menentukan reaksi kimia yang berlaku pada tanah dan

seterusnya menilai perkaitannya terhadap pertumbuhan

j agung .

Berdasarkan kepada mineralogi , s ifat muatan dan

tekstur , dua siri tanah telah dipilih untuk penyel idikan

di rumah kaea . Tanah tersebut adalah siri Bungor

( Ultiso l ) dan Prang ( Oksisol ) . Di dalam penyel idikan

pertama, profil tanah sedalam 90 em telah dimasukkan ke

dalam t i ub larutlesap PVC . Batukapur dolomit , gipsum dan

kombinasi antara kedua-duanya diberikan pada paras 0-15 em

xiv

dan proses larutlesap dij alankan selama 6 bulan . Pada

penyel idikan kedua tanah yang telah dicampurkan dengan

GML , gi psum dan kombinasi antara kedua-duanya digunakan di

dalam penyel idikan rumah kaca untuk melihat reaksi tanaman

j agung terhadap rawatan yang telah diberikan . Baj a asas

j uga diberikan 3 0 hari terdahul u dan j agung dituai selepas

berumur 40 har i .

Has i l analisis menunj ukkan Ultisol dan Oksisol adalah

berbeza dari segi mineralogi dan sifat muatannya . Tanah

Ultisol mengandungi kaol init manakala Oks isol mengandungi

kaolinit , gibsit dan goetit sebagai mineral utama . S ifat

k imia ketiga-tiga mineral tersebut dipengaruhi oleh

pember ian batukapur do lomit dan gips um .

GML meningkatkan pH tanah yang mengakibatkan

bertambahnya muatan negatif pada permukaan lempung . Ini

dapat menerangkan bagaimana Ca tetap kekal di bahagian di

mana GML diberikan . Di dalam tanah yang dirawat dengan

gips um , Ca bergerak lebih j auh ke dalam prof i l tanah ,

seterusnya dapat memperbaiki kekurangan Ca di profi l

bawah . Penyel idikan ini menunj ukkan GML dan kombinasinya

dengan gi ps um dapat memperbaiki keracunan Al di lapisan

atas serta memperbaiki kekurangan Ca dan/atau Mg di profi l

bawah .

S ul fat daripada gipsum dijerap oleh oks ida Fe

dan/ at au AI . Jerapan ini mengakibatkan peningkatan muatan

xv

negatif dan pH tanah . Fenomena ini ter j adi dalam Oks isol

kerana kandungan mineral oksida yang tinggi . Data dari

larutan tanah dan hasil larutlesap menunj ukkan gipsum

menyebabkan pemendakan alunit dan/atau j urbanit .

Tanaman j agung dapat tumbuh dengan lebih baik di

tanah Ultisol dan Oks isol di Malays ia sekiranya tanah­

tanah tersebut terlebih dahulu dirawat dengan GML berserta

gip s um dengan kadar dan kombinasi yang sesuai . Kadar 2 t

GML berserta 1-2 t gipsum ha-1 memberikan has il j agung yang

hampir tertinggi . Pada kadar tersebut , pH larutan tanah

meningkat dari 4 . 0 kepada kira-kira 5 . 3 , manakala

kepekatan Al dan Mn turun kepada 2 0 dan 6 �M . Ternyata

bahawa kepekatan Al di dalam larutan tanah mempunyai

perka itan pos itif dengan j umlah Al di dalam daun ,

sementara perkaitannya adalah negatif degan berat relatif

j agung . Kepekatan Ca dan Mg di dalam Iarutan tanah j uga

menunj ukkan perkaitan positif dengan j umlah Ca dan Mg di

dalam daun . Mg di dalam larutan tanah mempunyai perkaitan

positif dengan berat relatif j agung . Kaj ian ini

menj e laskan bahawa AI , Ca dan Mg di dalam larutan tanah ,

serta nisbah Ca/AI di dalam larutan tanah boleh digunakan

untuk menentukan tahap kemasaman tanah .

xvi

CHAPTBR I

INTRODUCTION

The world is us ing about 4 0 % of the potential land

sources for agricultural purposes ( Sanchez and Sal inas ,

1 9 8 1 ) . The areas which have high potential for

agricultural development are partly located in tropical

region where the soils are acidic and have low ferti lity

status . These soils are classified by the united states

Soil Taxonomy as Ultisols and Oxisols ( Soil Survey Staff ,

1 9 7 5 ; 199 0 ) . Oxisols are soils that have undergone

intensive weathering , and have oxic B hori z ons rich in

kaol inite and sesquoxides . They do not have arg i l l ic

hor i z ons . On the other hand , Ultisols are characteri z ed

by the presence of argi l l ic horizons . They are acid soils

and have base saturations of less than 3 5% at a depth of

75 cm .

Ultisols and Oxisols occupy about 7 2 % of the land

surface in Malaysia ( IBSRAM , 1 9 8 5 ) . The soi ls are acidic

in nature , with pH values ranging from 4 to 5 ( Tessens and

Shamshuddin , 198 3 ) . The soils are high in Al saturation

and base deficient . Their cation exchange capacities

vary with the change in pH . The low fertil ity status is

the reason for the soi ls being not agricultural ly very

productive , unless they are amended with l ime and/or

organic matter .

1

2

The charges on the surfaces of the oxides and

kaolinite in Ultisols and Oxisols are variable in nature .

The values change with pH and ionic strength ( Uehara and

G i l lman , 1 9 8 1 ) . The chemistry of the soils containing

these minerals can be manipulated by appl ication of

inorganic and organic amendments such as l ime , gypsum and

palm oil mil l eff luents .

Lime has been appl ied frequently in cocoa plantation

to reduce soil acidity . As a result , cocoa production has

improved . The yield of corn grown on Ultisols is reported

to improve as a result of l ime appl ication ( Shamshuddin

et a l . , 199 1 ) . The effects of these amendments on soil

chemical properties and yield of crops have been studied ,

but the mechanism of N03_, S042- and Ca2+ movements in the

soil prof i les treated with the amendments has not been

clearly explained .

Most of the Ca from lime appl ication does not move

beyond the zone of incorporation ( Pavan et al . , 1 9 8 4 ;

G i llman et al . , 19 8 9 ) , thus the subsoil remain def icient

in Ca after l ime application . Sumner et al . ( 19 8 6 )

suggested that Ca subsoil deficiency could be overcome by

surface appl ication of gypsum . Top soil and subsoi l

calcium deficiency can be alleviated by surface

application of l ime together with gypsum ( Pavan et a l . ,

19 8 4 ) .

3

The obj ectives of the study were : ( i ) to determine

the effects of dolomite limestone ( GML) and gypsum

appl ications on chemical properties of an Ultisol and

Oxisoli ( i i ) to study the mechanism of cations and anions

movement in the soils; and ( ii i ) to determine the effects

of l imestone , gypsum and their combinations on corn

growth .

CHAPTER II

REVIEW OF LITERATURE

Parent Materials

Soil series in Malaysia have been defined at least in

part by the rocks from which the soils are derived

( Paramananthan , 19 8 7 ) . Beside parent materia l ,

geomorphology plays a very important role in soi l

formation i n Peninsular Malays ia ( Paramananthan and

Zauyah , 19 8 6 ) . Soi l chemical properties are also being

used to def ine soil series . The differences in chemical

and mineralogical composition of different rock types are

often reflected in the resultant soil types . For instance ,

the rate of weathering of the rock depends on its iron

content. Rocks with high iron content weather more

readily , resulting in soils which have low silt content

and r ich in oxides of iron and aluminium .

Granite is the most important rock type in Peninsular

Malaysia , occupying large areas in the upland . Other

rock types include shale , limestone , sandstone and

volcanic tuff . Figure 1 shows rock type distribution in

Peninsular Malays ia . These rocks become the maj or parent

materials of the soils in the Peninsula .

4

o alluvIum

IITJ granite

• baa.,t

iii gabbro

� tuff, rhyollt., daclt.

II IIm •• tone

acal.

a 50 100km • , «

Ell oth.r. Including .. ndaton., ahal.,

Figure 1

Rock Type Distribution in Penins ular Malaysia ( Law, 1968; Staufer, 1973) .

5

6

Detailed morphological , chemical , mineralogical

studies of a wide range of soils have been carried out in

an effort to characterize and reclassify the major soils

found in Peninsular Malaysia ( Paramananthan , 19 7 7 ; Tessens

and Shamshuddin , 198 3 ) . The results of these studies have

been reported in journals , seminars and monographs . The

information gathered from these publications has been used

to identify soil series required for this study .

weatherinq

Malaysia is located on the Equator . Like many of the

tropical countries in southeast Asia , Malaysia has a warm

humid climate , which is classif ied as subtype Af using

Koppen ' s Classification ( Paramananthan and Eswaran , 1 9 8 3 ) .

The mean annual air temperature is 2 4 °c , while the mean

annual rainfall is 2 00 0 rom . This high temperature and

rainfal l result in a high degree of rock weathering . The

soils that form under these conditions are highly leached

and weathered .

The rapid rock weathering in Ma laysia results in

soils containing kaolinite , iron oxide and a luminium oxide

( Tessens and Shamshuddin , 1 9 8 3 ; Paramananthan and Eswaran ,

1 9 8 3 ) , which are clay minerals with variable charges .

Most of the physico-chemical properties of the soi ls are

inf luenced by the properties of these minerals . The

7

minerals have low nutrient retention properties , thus , the

soils are reduced almost to an inert medium ( Eswaran and

Sys , 198 4 ) .

Mineralogy

As a stated above , weathering under condition of high

temperature and rainfall produces the soils containing

1 : 1 clay minerals and oxides of Al and Fe . The dominance

of a mineral type depends largely on the degree of

weathering . Less weathered soils ( fig . 2 ) contain large

amounts of kaol inite , mica ( 10 A) and smectite ( 14 . 5 A) .

smectite was absent in a more highly weathered soil ( fig .

3 ) . Gibbsite and kaol inite dominate the clay fraction of

a soi l in an ultimate stage of weathering ( f ig . 4 ) . Data

in table 1 shows the mineralogy of the soil residual

parent materials in Peninsular Malaysia arranged in

increasing order of degree of weathering . It can be

noticed that Fe oxides increase with degree of weathering .

On the other hand , mica content decreases with increase

degree of weathering .

3.51 5 7.2 1214.5

Figure 2

Ma

Glycol

K

550 C

X-ray Diffractograms of the Clay FractiQn ( B2 t ) in Kuala Brang Series Soil ( Shamshuddin, 1 9 9 0 ) .

8