Soil Profiles: Prang

Typifying Pedon
Type Location
Range in Characteristics
Competing Soils and Their Differences
Setting
Principal Associated Soils
Drainage and Permeability
Use and Vegetation
Distribution and Extent
Series Established
Remarks on Classification
Suitability for Agriculture
Analytical Data

Prang Series
The Prang Series is a member of the Segamat Family which is a very fine, oxidic, isohyperthermic, red Tipik Akrolemoks. It is developed over amphibolite and schist parent materials. These are deep (> 100 cm) uniformly red coloured soils. These soils are characterized by thin clayey A horizons with dark reddish brown colours and B horizons having yellowish red to red colours, heavy clay textures with very weak, medium to fine subangular blocky structures and very friable consistence. These soils are often very deep but hard petroplinthite concretions may occur as a loose band at depths below 100 cm.

Typifying Pedon 

Type Location 
Soils of the Prang Series were first established in Prang Besar Estate, near Kuala Lumpur during the Reconnaissance Soil Survey of Selangor (Wong 1966). The above pedon was described from the same estate at the midslope of a rolling hill (16–20% or 8–10°) slope at an elevation of about 70 metres (200 ft) above sea level. Location: Topographic Sheet 3756, 2°55′ N, 101°42′ E (Grid Reference 3756 – 120230 m)

Range in Characteristics
The A horizons of the Prang Series range in colour from dark reddish brown to reddish brown (5YR3/3, 3/4, 4/3; 2.5YR2.3/4) with clay loam to clay textures. The B horizons range in colour from red to yellowish red (2.5YR4/6, 4/8, 5/6, 5/8; 5YR4/6, 5/6, 5/8). Textures are uniformly clayey with clay contents often over 65% but in the mechanical analyses lower clay contents are obtained due to poor dispersion. Structures are weak to very weak medium to fine subangular blocky and consistence very friable. Clayballs are sometimes found in the B horizons. Horizonation is weak and the profiles are often deep. Occasionally particularly at the crest of the hills petroplinthite nodules or iron coated schist material may be present but embedded in the clayey B matrix. This laterite band often occurs at depths of about one metre or greater. Sometimes a thin loose band of pisiform petroplinthite nodules may also occur within one metre but these are then thin bands.

Competing Soils and Their Differences 
The Prang Series because of its typical reddish colours is easily mistaken for the Segamat, Patang, Kampong Kolam, Tarat and Apas Series. In fact unless the parent material is known it is virtually impossible to separate these soils. The Prang Series often has somewhat slightly more sand compared to the Segamat Series but as mentioned earlier poor dispersion may even make such differentiation impossible. The Patang Series mapped in Terengganu and Johore is also very similar to the Prang Series. The Patang Series is reported to be slightly firmer with depth and often has outcrops of hornfels at the surface. The Patang Series has a CECclay of more than 1.5 cmol. The Tarat Series and Apas Series are developed over andesites or basalts and have cation retention capacity over 1.5 cmol (+) kg–1 clay.

Setting 
The soils of the Prang Series typically occur on undulating to rolling terrain. They have to-date been mapped at elevations of 0–100 metres (0–300 ft). These soils often occur on the lower slopes of hills which have the Malacca or Seremban Series on their crests.

Principal Associated Soils 
The Prang Series have often been mapped in association with soils of the Munchong Series, Chat Series, Seremban Series and Malacca Series. Sometimes they have also been mapped in association with soils of the Serdang Series. The Munchong Series is separated from the Prang Series by its yellower hues. The Munchong Series has hues of 7.5YR and 10YR in the upper part (50 cm) of the B horizon. The Chat Series has colours similar to that of the Munchong Series and has an argillic horizon. The Seremban Series also has red colours but is characterized by the presence of platy iron-coated schist fragments within 50 cm. The Malacca Series is characterized by the presence of a thick band of angular petroplinthite gravels which occur within 50 cm of the surface.

Drainage and Permeability 
Drainage in the Prang Series is somewhat excessive. Permeability is good. These soils because of the aggregation of the clay are very porous.

Use and Vegetation 
The Prang Series has been mainly planted with rubber, fruit trees and oil palm. In some areas these soils are still under primary forest vegetation.

Distribution and Extent 
The Prang Series as defined here has been mapped in around Kajang in Selangor, near Tanjong Malim in Perak, around Sg. Tebak in Terengganu and near Bekok in Johore and in isolated pockets in Malacca and Pahang. Recently it has also been found in Kedah. The actual extent of these soils is not fully known as they have often been mapped in association with other soils.

Series Established 
This soil was established in Prang Besar Estate, near Kuala Lumpur. The source of name is Prang Besar Estate, Selangor, Peninsular Malaysia. This area has now been cleared for urban development.

Remarks on Classification 
The Prang Series is classified here according to the Malaysian Soil Taxonomy – Second Approximation (Paramananthan 1998) as a member of the very fine, oxidic, isohyperthermic, red family of Tipik Akrolemoks which is developed over amphibolites and schists. They are classified here as soils having a deep oxic horizon, heavy clay textures, weak structures and a low (< 1.5 cmol (+) kg–1) clay cation retention capacity in the B horizon. In the Keys to Soil Taxonomy – Eighth Edition (Soil Survey Staff 1998) the Prang Series would probably be classified as Typic Hapludox. In the FAO/ UNESCO Soil Map of the World – Revised Legend (FAO 1990) the Prang Series would probably be classified as Geric Ferralsols.

Suitability for Agriculture 
Soils of the Prang Series have a somewhat excessive drainage. Thus moisture availability particularly the establishment of the crop can be difficult. These soils also have low nutrient content and can fix large amounts of phosphorus. These soils have however been classified as Class 1 soils for rubber. In the case of oil palm and cocoa the rainfall distribution pattern of the area where the Prang Series occurs will determine its suitability rating.