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Perunika 10(2), 125 - 134 (1987)

Soil Suitability and Management Implications of Soil Taxonomywith Special Reference to Tree Crop Cultivation

S. PARAMANANTHANDepartment of Soil Science,

Faculty of Agriculture,Universiti Pertanian Malaysia,

43400 Serdang, Selangor, Malaysia.

Key words: Soil suitability; management; soil taxonomy; tree crop cultivation.

ABSTRAK

Di kebanyakan negara yang sedang membangun, tinjauan tanah dijalankan dengan tujuanutamanya untuk menafsirkan keputusan daripada tinjauan tanah ini bagi kegunaan pertanian.Sekiranya keuntungan maksimum daripada tanah dikehendaki, satu pemilihan tanaman yang sesuaiadalah perlu. Dinegara-negara ini kegunaan Taksonomi Tanah sebagaisatu sistem pengelasan tanahsemakin meningkat. Kertas kerja ini meneliti tafsiran-tafsiran penyesuaian dan pengurusan tanahyang dapat dibuat dengan menggunakan Taksonomi Tanah, bagi tanaman jangka panjang sepertigetah, kelapa sawitt koko dan kelapa. Iklim, topografi, kelembapan, keadaan fizik dan kimia tanahtermasuk dalam limitasi-limitasi yang mempengaruhi tumbesaran tanaman. Tiap-tiap satu daripadalima kumpulan ini boleh dibahagikan pula kepada ciri-ciri tanah yang berlainan. Kesemua limitasi inikecuali topografi boleh ditajsirkan mengikut pengelasan famili dalam Taksonomi Tanah. Disampingitu keperluan pengurusan bagi limitasi ini juga dapat ditentukan. Penggunaan Taksonomi Tanahjuga dapat memberi kemudahan kepada saintis-saintis tanah dari negara-negara asing untuk ber-hubung diantara satu sama lain dan seterusnya dapat menjimatkan masa dan wang bagi mengulangipercubaan-percubaan yang telah dijalankan.

ABSTRACT

Soil surveys are carried out in many developing countries with the main objective of inter-preting the results of these soil surveys for agriculture use. A proper selection of crops is vital if maxi-mum benefits from the land are to be obtained. Soil Taxonomy as a system of soil classification isincreasingly being used in these countries. This paper examines the soil suitability and managementinterpretations that can be made using, Soil Taxonomy, for perennial cropz viz. rubber, oil palm,cocoa and coconut. Limitations that affect crop growth include climate, topography, wetness,physical and chemical soil conditions. Each of these five groups can be further subdivided into diffe-rent land characteristics. Except for topography, most of the other limitations can be evaluated usingthe family classification in Soil Taxonomy. In addition various management requirements to over-come these limitations can also be ascertained. Soil Taxonomy is also a means by which soil scientistsjrorn different countries can communicate with one another thereby saving both time and money inrepeating experiments.

INTRODUCTION pose of any classification is to organize our know-The logic of soil classification has been sum- ledge into groups so that the properties of themarised by Cline (1949). He stated that the pur objects classified may be easily remembered and

S. PARAMANANTHAN

the relationships between members of groupsand between members within a group are readilyunderstood. Cline also states that any classifica-tion must have specific objectives. Thus any pro-posed system of soil classification should satisfythese objectives.

In many countries particularly, the develop-ing countries of the Tropics, soil classificationand soil surveys have and are being carried outwith the objective of interpreting the results ofthese soil surveys for agricultural use. Data fromsoil surveys is vital for crop selection and for themanagement of the soils so that maximumbenefits can be obtained. Increasingly morecountries are using Soil Taxonomy (Soil SurveyStaff, 1975) as a basis for carrying out soilsurveys and interpreting the resultant soil maps.

The objectives of this paper is to examinethe interpretations that can be made using, SoilTaxonomy, for the suitability and managementof perennial crops. The importance of SoilTaxonomy as a means of technology transfer forperennial crops will also be briefly discussed.

CATEGORIES OF CLASSIFICATIONSix categories have been recognized in SoilTaxonomy, viz: Order, Suborder, Great Group,Subgroup, Family and Series. These categoriesserve specific purposes and the amount of detailthat goes into each of the definition increases inthe lower categories. In addition since SoilTaxonomy is an hieracial system, any propertyor criteria used at a higher level is also implied atthe lower levels. The general criteria used ateach categorical level is summarised below.

OrdersThe orders are differentiated by the presence orabsence of diagnostic horizons or features. Theseare indicators of differences in the degree andkinds of dominant sets of soil-forming processesthat have helped to form the soil. Ten orders aredescribed in Soil Taxonomy — Alfisols,

Entisols, Histosols, Inceptisols,Oxisols, Spodosols, Ultisols and

Aridisols,Mollisols,Vertisols.

SubordersThe suborders generally are defined on the basisof properties that affect the current processes of

soil development. In most suborders, soilmoisture and temperature regime are the pro-perties used. In the case of organic soils — Histo-sols — the degree of decomposition of theorganic soil material is used.

Great GroupsIn this category, a number of soil properties areused. The whole soil is characterized includingthe assemblage of horizons and the most signi-ficant property of the whole soil as determinedfrom the number and importance of accessoryproperties. Although the differentiating pro-perties of the great group are few, there aremany accessory properties.

SubgroupsThe categories above the subgroup focus on theindications of causes of sets of processes thatappear to dominate the course of degree ofdevelopment. However, many soils have in addi-tion to these, properties that are subordinate butyet important indications of soil-forming pro-cesses.

Within a given great group, the soil mayshow subordinate indicators of processes that aredominant in other orders, suborders or greatgroups but in the given great group these pro-cesses serve only to modify other more importantand dominant processes. Identifying these lesssignificant processes at the subgroup level helpsto show the relationship to other kinds of soils.

FamiliesIn this category, the intent has been to group thesoils within a subgroup that have similar physicaland chemical properties affecting their responseto use and management in particular to agri-culture.

SeriesThe soil series is the lowest category. Differen-tiating characteristics of a series cannot fall out-side the limits established for the family.

SOIL SUITABILITY ANDMANAGEMENT INTERPRETATIONS

126

General PrinciplesThe determination of the suitability of a piece of

PERTANIKA VOL. 10 NO. 2, 1987

SOIL SUITABILITY AND MANAGEMENT IMPLICATIONS OF SOIL TAXONOMY

land for a specific agricultural use and the typeof management is one of the more importantuses of a soil map (Paramananthan and Law,1980). Before examining how the Soil Taxonomycan be used for this purpose, it may be pertinentto examine briefly the general principles of suchinterpretations.

Experience and research on crops grown ona variety of soils form the basis of such inter-pretations. This experience may come frommany sources including experimental andfarmer experience. The lack of a common basisfor comparing soils between different countrieshas for a long time limited the use of such data towithin a country. However, with the wider use ofSoil Taxonomy, the data base used has becomeinternational.

Based on research and experience, tableshave been developed showing the limitations tocrop growth. Initially these tables only con-sidered the soil characteristics (Wong, 1974).Today however, other criteria such as climateare also included (Bunting, 1981). The limita-tions to crop growth are rated as being minor,moderate, serious or very serious for the growthof a particular crop with the degree of severitybeing based on estimated decline in yield due tothat characteristic.

From the results of the soil survey, a tableshowing the physical and chemical charac-teristics of the soil can also be developed. Inevaluating a piece of land for the suitability of aparticular land use, one has just to compare thetable of limitations to crop growth with that ofthe soil properties. By this comparison, the landcan be evaluated for that particular land use. Inthe simplest method of evaluation, the soilmapping unit is given the worst rating it receivesas an overall land suitability rating. However,some limitations such as drainage class, presenceof acid sulfate horizon may be overcome byvarious management practices. Hence it ispossible to identify various management prac-tices that can be used to overcome a particularlimitation thereby upgrading the soil.

Crop Growth LimitationsDepending on the crop, a variety of factors canaffect growth. In general however, these limita-tions can be sub-divided into five main

groups: —i) Climatic Characteristics

ii) Topographyiii) Wetnessiv) Physical Soil Conditionsv) Soil Fertility Conditions

Each of these five groups can be furthersub-divided into different land characteristicsdepending on how these factors will influencethe growth, yield and management of that parti-cular crop. The class limits or degree of limita-tion for each characteristic will vary according tohow that characteristic affects the particularcrop. The list of characteristics used is notexhaustive and can be increased or decreasedbased on new data from research. The classlimits for the degree of limitations are more diffi-cult to establish but are established on the basisof research findings and experience.

Based on the author's experiences with thegrowth of rubber, oil palm, cocoa and coconuton a variety of soils. Tables 1, 2, 3 and 4 havebeen developed for use in Malaysia (Parama-nanthan, in press).

Use of Soil Taxonomy in the EvaluationProcessAs mentioned earlier, the criteria used at thefamily category in Soil Taxonomy have beenselected in such a way as to make agriculturalinterpretations. However depending on the landcharacteristics concerned they are used atvarious levels.

Climatic Characteristics. The climaticcharacteristics used in the land evaluationprocess include the presence/absence of a dryseason and the mean annual temperattrre. Bothof these characteristics are used in SoilTaxonomy. The soil moisture regime is oftenused as the Suborder level in Soil Taxonomy.Soils having an ustic moisture regime forexample such as the ustults are not suitable forboth oil palm and cocoa while they are marginalfor rubber. The soil temperature regime is usedat the family level and only those soils having anisohyperthermic temperature regime are wellsuited for the first three crops concerned. Thosewith isothermic and isomesic temperatures arenot suited for these crops.

PERTANIKA VOL. 10 NO. 2, 1987 127

S. PARAMANANTHAN

TABLE 1Evaluation of land characteristics for rubber

Characteristic

Climate

Annual rainfall (mm)

Loss of tapping days (months)

Dry season (months)

Mean annual max temp (°C)

Mean annual min temp (°C)

Mean annual temp (°C)

Topography

Slope (%)

Wetness

Drainage

Not limitingSI

+ 2,000

- 1

- 1

+ 29

+ 20

+ 25

0-12

Good

Degree of limitation

MinorS2

1,700-2,000

1 - 2

1 - 2

27-29

18-20

22-25

12-23

Moderate

ModerateS3

1,450-1,700

2 - 4

2 - 4

24-27

16-18

20-22

23-38

Imperfect

SeriousN l

1,250-1,450

+ 4

+ 4

22-24

14-16

18-20

38-48

Imperfect &

Very seriousN2

-1,250

—

+ 4

- 2 2

- 1 4

- 1 8

+ 48

Poor

Flooding

Physical soil conditions

Texture/structure '

Depth (cm)

Soil fertility conditions

Weathering stage (effective CEC)

Base saturation (%) A horizon

Organic carbon (%) A horizon

Not flooded

CL, Co, SC, SiCs, SCL, L SL, LS (f)Cs L

50-100

high W.T.

Minor Mod-severe

+ 150

+ 16

+ 35

+ 1.5

100-150

- 1 6

- 3 5

-1.5

LS (co), Sf,Cm, SiCm

25-50

Sco

- 2 5

From Tables 1 -3 , it appears that bothcocoa and oil palm are more sensitive tomoisture stress compared to rubber and henceyields of oil palm and cocoa will be seriouslyaffected by moisture stress. From these conside-rations one can interpret that oil palm and cocoagrown on well drained soils with an oxic horizonespecially those having red colours and wellaggregated structures would be seriously affectedby yield fluctuation. Hence rubber is preferredon such soils (Paramananthan and Eswaran,1984). It is for this reason that the northern partof Peninsular Malaysia is considered to be not

suitable for both cocoa and oil palm as theclimate there is marginal to ustic.

Topography. Topography or slope is oftenmapped at the phase level on a soil map. Thedifferent systems of harvesting employed for thethree crops considered, make slope an importantconsideration. Slopes also affect the erodabilityof the soil. This criteria is not readily inferredfrom the classification of the sol using SoilTaxonomy.

Wetness. The wetness characteristic isdivided into drainage and flooding. Thedrainage class of a soil can be inferred from the

128 PERTANIKA VOL. 10 NO. 2, 1987


TABLE 2Evaluation of land characteristics for oil palm


Characteristic Not limitingSI

MinorS2

ModerateS3

SeriousNl

Very seriousN2

Climate


Dry season (months)

Mean annual max temp (°C)


Mean annual temp (°C)

Topography

Slope

Wetness

Drainage

Flooding


Texture/structure

Depth (cm)

Depth to top of sulfuric horizon

Soil fertility conditions


Base saturation (%) A horizon

Organic carbon (%) A horizon

Salinity millimohs (50cm)

+ 2,000

+ 29

+ 20

+ 25

0-4

1,700-2,000 1,450- 1,700 1,250- 1,450

- 1 1-2 2 -3

27 - 29 24 - 27 22 - 24

18-20 16-18 14-16

22-25 20-22 18-20

4-12 12-23 23-38

Moderate toimperfect

Not flooded

Cs, SC, CL,SiCs, SiCL

100 +

100 +

+ 16

+ 35

+ 1.5

0 - 1

Well andsomewhatexcessive

Not flooded

Co, L, SCo

75-100

75-100

- 1 6

20-35

-1 .5

1 - 2

Poor (aerie)(easily

drained)

Minor

SCL

50-75

50-75

- 2 0

-

2 - 3

Poor (typic)difficult to

drain

Moderate

SL, LSf

25-50

25-50

-

-

3 - 4

-1,250

3 +

- 2 2

- 1 4

- 1 8

+ 38

Very poor

Severe

LSco, S

- 2 5

- 2 5

4 +

classification of the soil. Soils which are poorlydrained often have mottles with a low chromaand have an aquic moisture regime. Hence soilsthat belong to the Aquepts and Aquults have anaquic moisture regime. Soils that have colourswith a low chroma lower down in the subsoil areimperfectly drained and this is indicated by thesubgroup in the classification e.g. Aquic Tropu-dult. Oil palm tolerates poorly drained condi-tions while rubber does not. Cocoa on the otherhand can grow well on poorly drained soils if the

watertable is kept below 75cm. Thus manycoastal areas which have been drained artifi-cially have soils of the order Aquepts. Such soilscan be planted with oil palm and cocoa but areconsidered to be unsuitable to marginal forrubber. On the other hand, the imperfectlydrained soils (aquic subgroups) can support allthe three crops. With improvement in drainage,the performance of rubber improves thePaleudults, Haplorthox and Dystropepts.


S. PARAMANANTHAN

TABLE 3Evaluation of land characteristics for cocoa

Characteristic

Climate


Length of dry season (months)



Relative humidity (month withlowest value)

Topography

Slope (%)

Wetness

Drainage

Flooding


Texture/structure

Depth (cm)

Depth to acid sulfate layer

Chemical soil conditions


Base saturation (% A horizon)

Organic carbon (% A horizon)

Organic carbon (% B horizon)

Salinity (m mhos)

Not limitingSI

1,600-2,000

- 1

- 2 8

+ 20

45-60

0 - 4

Well tomoderate

Not flooded

Cs, SC, CL,SiCs. SiCL

100 +

100 +

+ 24

+ 50

-1 .5

-1 .5

0-0.5


MinorS2

1,400-1,6002,000-2,500

1 - 2

28-30

15-20

40-4456-60

4 - 12

Somewhatexcessiveimperfect

-

Co, L. SCo

75-100

-

16-24

35-50

1.5-2.4

-

0.5-1

ModerateS3

1,200-1,4002,500-3,500 3

2 - 3

+ 30

13-15

35-3961-65

12-23

Somewhatpoor

SCL

50-75

75-100

- 1 6

20-35

2.5-5.0

1.5-3.0 3

1-1.5

SeriousNl

-1,200.500-4,500

3 - 4

-

10-13

30-3466-75

23-38

Poor

Minor

SL, LSf

25-50

50-75

—

- 2 0

-5.0

.0 +

1.5-2

Very seriousN2

+ 4,500

+ 4

—

- 1 0

-30+ 75

+ 38

Very poor

Mod-severe

LSco, S

- 2 5

- 5 0

-

-

-

—

+ 2

Physical Soil Conditions. A number of soilcharacteristics can be evaluated under thiscategory. The texture or particle-size class whengravels are present is an obvious characteristicthat can be used. In Soil Taxonomy, the particlesize class is used at the family level and hence thisinterpretation can be readily made. In order toaccomodate textural variations with depth and

the presence of stonelines, the characteristic isevaluated using a weighted average to 100cm.Where gravel layers are present a further down-grading is used. Within one textural class e.g.clay and soil may have fine structures and friableconsistence as in Oxisols or be coarse structuredand compact as in some Tropudults. This dif-ference can often be inferred from some acces-

130 PERTANIKA VOL. 10 NO. 2. 1987


TABLE 4Evaluation of land characteristics for coconut

Characteristic

Climate


Mean annual temperature (°C)

Leneth of dry season (months)

Not limitingSI

+ 2,000

27 - 32

- 1


MinorS2

1,600-2,000

24-2632 +

1-2

ModerateS3

1,250-1,600 1

22 - 24

2 - 3

SeriousNl

,000 1,250

20 - 22

3-4

Very seriousN2

-2,000

-20

+ 4

Topography

Slope (%)

Wetness

0 - 4 4-12 12-23 23-38 38 +

Drainage

Flooding

Physical soils conditions

Texture and structure

Depth (cm)

Chemical soil condition

Weathering state (effective CEC)

Base saturation (A horizon %)

Organic carbon (A horizon %)

Salinity (m mhos) 0 - 4

Imperfect,moderately,well, well

Not flooded

CL, Co, SC,Cs, SCL, L

+ 100

-

+ 35

+ 1.5

Somewhatexcessive

-

LS, SICsSL

75-100

-

20-30

-1.5

4 - 8

Poor

Minor

S

50-75

-

- 2 0

-

8-16

Very poor

Moderate

Cm, SICm

25-50

-

-

-

16-20

Severe

—

- 2 5

-

-

+ 20

sory properties. Oxisols generally tend to be finestructured and friable thereby making rootpenetration and workability relatively easy.

The presence of rock or other substratum willseverely inhibit root growth. In Soil Taxonomythe lithic, paralithic and petroferric contactreflect these conditions. These criteria are usedat the subgroup level. Similarly the presence of asulfuric horizon at various depths in the soil willdetermine its suitability and management. Asulfuric horizon which occurs within 50cm of thesoil surface will key the soil out at great grouplevel as a Sulfaquept. If the sulfuric horizonoccurs below 50cm depth then it is indicated at

the subgroup level as a Sulfic Tropaquept. Theutilization and management of these scid sulfatesoils is strongly related to the depth of this acidsulfate layer (Paramananthan and Eswaran,1984). The knowledge of the depth of thesulfuric horizon is vital to determine the type ofwater control and management that has to beused if these soils are to be successfully used foragriculture.

Soil Fertility Conditions. The low fertility oftropical soils has long been considered to be thecause of low yields. The mineralogy and organicmatter content of the soil reflect the fertilitystatus of the soil. The mineralogy of the soil is


S. PARAMANANTHAN

reflected in the mineralogy class at family level.Soils belonging to the kaolinitic or oxidic classare obviously less fertile than those of the mixedmineralogy class. Soils of the oxidic family mayalso present problems of phosphate fixation. Thelow fertility of tropical soils is often reflected intheir low effective cation exchange capacity.Thus soils with an oxic horizon have an effectiveCEC of less than 16 while soils belonging to theoxic or orthoxic subgroup have an effective CECof less than 24. This low CEC implies that if highyields are to be obtained and maintained a goodmanurial programme is essential.

The adaptability of the different perennialcrops to such low fertility conditions varies.Rubber is somewhat more tolerant of such soilswhile cocoa is least tolerant. In Oxisols, thecalcium and magnesium levels are often low, afactor which is critical for cocoa. On the otherthan, fertile soils developed over marine clayswith smectitic mineralogy have high values forthese two elements. This high level of magne-sium can cause coagulation of latex in rubberand hence reduce yields.

In many Oxisols, the only source of nut-rieints is the organic matter. The organic mattercontent of these soils is reflected in the colour ofthe surface horizons. Thus the darker coloured

umbric epipedons are probably more fertile thanthe light coloured ochric epipedons. The basesaturation which is also used as a soil fertilitycharacteristic is used both at the order level vizAlfisols and Ultisols and at the great group levelviz Dystropepts and Eutropepts.

MANAGEMENT IMPLICATIONSThe differing soil and climatic requirements ofthe tree crops considered play a dominant role inthe crop diversification programme. In thepre-1950 years rubber was planted on bothpoorly drained Aquepts and well drainedOxisols. However, once soil survey and crop per-formance data were available rubber was movedto the Great Groups of Paleudult, Tropudult,Acrorthox and Haplorthox. Oil palm on theother hand was increased on the Tropaqueptsand Sulfaquepts. Cocoa, requiring more fertilesoils was planted on the Tropaquepts, Tropu-dults and Eutrorthox. The extent of coconut inMalaysia has been reduced somewhat being nowconfined to the Tropaquepts and Sulfaquepts.

The relationship between crop performanceand soil units have been studied by many workersan summarised by Ng (1983). This is as repro-duced in Table 5. From this table it is obviouswhy oil palm or cocoa/coconut is preferred to

TABLE 5Yield performance on different soil groups (After Ng, 1983)

Soil group

Tropaquept

Sulfaquept

Dystropept

Sulfaquent

Paleudult

Tropudult

Acrothox

Haplorthox

Quartzipsamment

Tropaquod

Tropohumod

Tropofibrist

Rubberkg/ha/yr.

1,300-1,500

1,200

1,400-1,700

700

1,500-1,700

1,400-1,600

1,400-1,800

1,700

800

600

700

600

Oil palmtonne/ha/yr.

25-30

20-25

18-22

15-20

20-22

20-22

20-22

22-25

18-20

-

-

12-15

Cocoakg/ha/yr.

1,000-1,200

700 - 800

600 - 700

400 - 500

800 - 900

900-1,000

900-1,100

1,100-1,200

500 - 600

-

-

<400

Coprakg/ha/yr.

1,500- 1,800

1,000- 1,200

-

600 - 800

-

-

-

-

400 - 500

500 - 600

—

1S2 PERTANIKA VOL. 10 NO. 2, 1987


TABLE 6Principal & subsidiary nutrient inputs for various tree crops (After Ng. 1983)

Soil group

Tropaquept

Sulfaquept

Dystropept

Sulfaquent

Paleudult

Tropudult

Acrothox

Haplorthox

Quartzipsamment

Tropaquod

Tropohumod

Tropofibrist

Rubber

N, k

P, n, k

P, N

P

N, K. P

N, K, p

N, K, P

N, K, p

K, P, N, mg

-

-

-

Oil palm

N. k

P, CA, n, k

P, N, k, mg

P, CA, n, k

N, K, P, mg

N, K, P. mg

N, P, K, mg

N. P. k, mg

N, P, K, MG, B

-

-

CU, K, CA. B

Cocoa

N, CA, k

CA. P, N

CA, P, N

CA, P. n,

CA( N, K,

CA. N, K,

CA, P, N.

CA, P, N,

-

-

-

-

k

P

P

k

k

Coconut

N, k

P, ca

-

P. CA, n

N, K, P

N, K, P

-

-

-

k, n

K, n, p

K, CA

Note: Capital letter denotes Principal Input.Small letter denotes Subsidiary Input.

rubber on Aquepts.The increasing interaction between the use

of soil survey data and cultivation practice andfertilizer use has resulted in the identification ofthe nutrient inputs required for a particular cropon a specific soil unit. This information has beencomplied by Ng (1983) and is given in Table 6.From this table it can be seen that priorities ofnutrient inputs vary with soil characters as wellas crops. Thus in the case of oil palm, the lowerdemand for nutrients is apparent in most of theAquepts while higher nutrient requirementsincluding copper and boron are needed on thePsamments and Fibrists. For cocoa, calcium is anecessity but not for rubber.

POTENTIAL FOR AGROTECHNOLOGYTRANSFER

In the past, large amounts of money, time andenergy have been wasted by duplicating researchin many countries. This was because no commonsystem of soil classification was used. However,with the introduction and use of Soil Taxonomy,a common basic language of communication hasbeen developed. The Soil Taxonomy hasenabled us to compare soils in different countriesand assist in the transposing of research findings

from one country to another.If a Malaysian soil scientist says that the

Rengam Series is well suited for rubber, oil palmand cocoa, it does not mean very much to othersoil scientists who are not familiar with the soil.However, if he says in addition that the RengamSeries is a clayey, kaolinitic isohyperthermic,Typic Paleudult developed over granite, thenthe soil scientist in Thailand can equate this soilwith the Phuket Series in their country. Theresearch findings on the Malaysian soil couldthen be used in Thailand as a basis for furtherresearch without the need to repeat any basicexperiments already carried out in Malaysia.This transfer of technology is much easier withperennial crops as these crops are less demand-ing. Annual crops depend largely on topsoilcharacteristics. These characteristics can beeasily modified by erosion. Subsoil characteris-tics which are more stable are used in the evalua-tion of soils for perennial crops.

CONCLUSIONThe soil family in Soil Taxonomy has beendefined to assist in making interpretations foragriculture. The classification of a soil to thefamily level is a summary of both land and soil

PERTANIKAVOL. 10 NO, 2, 1987 133

S. PARAMANANTHAN

characteristics which can assist in the landevaluation and management. It is apparent thatmany of the criteria used in Soil Taxonomy canbe used to interpret for evaluating these soils forperennial crops. By matching our experience ofcrops grown on a variety of soils, the necessaryinterpretations on suitability is feasible.

Soil Taxonomy also assists research workersby providing a means of communication withone another. This has made the need to repeatmany experiments obsolete and transfer oftechnology between countries a reality.

REFERENCES

BUNTING, E.S. (1981): Assessments of the Effects onYield of Variations in Climate and Soil Charac-teristics for Twenty Crop Species Tech. Note No.12. Land Resources Evaluation with Emphasis onOuter Islands Project, Ministry of Agriculture,Indonesia and UNDP/FAO.

CLINE, M.G. (1949): Basic Principles of Soil Classifica-tion. SoilSci. 7:81-91.

NG, S.K. (1983): Applications of Soil Survey andClassification for Tree Crop Development andImprovement — The Malaysian Experience.Proc. 4th Int. Forum on Soil Taxonomy and

Agrotechnology Transfer. Dept. of Land Deve-lopment Thailand, SMSS and USAID p. 272 -281,

PARAMANANTHAN. S. and W.M. LAW. (1980): A BasicResource Inventory. Proceedings Silver JubilieeCongress on Science and Technology in ResourceDevelopment. Kuala Lumpur, 1980, H.M.Collier, Malayan Scientific Association, KualaLumpur, 1981.

PARAMANANTHAN. S. and H. ESWARAN. (1984):Problem Soils of Malaysia. Their Characteristicsand Management. In: Problem Soils of Asia.Food and Fertilizer Technology Centre BookSeries No. 27, p. 1 -12 .

PARAMANANTHAN, S. (in press). Guidelines for LandEvaluation in Malaysia.

SOIL SURVEY STAFF. (1975): SOIL TAXONOMY, ABasic System of Soil Classification for making andInterpreting Soil Surveys. Soil ConservationService, U.S.D.A. Agric. Handbook No. 436, 446pp.

WONG. I.F.T. (1974): Soil-Crop Suitability Classifica-tion for Peninsular Malaysia. Soil and AnalyticalServices. Bulletin No. I. Ministry of Agricultureand Fisheries, Kuala Lumpur, Malaysia.

(Received 26 July, 1986)

134 PERTANIKA VOL. 10 NO. 2, 1987

soil suitability and management implications of soil ...pertanika.upm.edu.my/pertanika papers/pert...

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