8342937101

EDGARDO A. AUXTERO,J. SHAMSHUDDIN AND S.PARAMANAN I HAN

1.    To characterize acid sulfate soils in Pulau Lumut morphologically, chemically and mineralogically

2.    To classify the soils according to Soil Taxonomy (Soil Survey Stall 1987).

MATERIALS AND METHODS

Acid sulfate soils for this study were sampled from Pulau Lumut, which isan islandwithanapproximate size of6000 ha, situated off Port Kelang, Selangor, Malaysia (Fig. /).The drained part of the island was divided into two parts:

1.    Cultivated areas (drained > 25 yr)

2.    Newly reclaimed areas (drained in 1982)

area were regarded as tnie acid sulfate soils a defined by the Malaysian Soil Classifieation Systen (Param an ant han and Noordin \ 986). Fig. 2show soil distribution in the island, while l abie 1 give-the relevant physico-chemical data of the soils iden tified.

Chemical and Mi nera logi rai A nalyses Soils were sampled according to genetic horizom The sam pies were air-dried, ground and sievec through a 2 mm sieve. Sonie analyseswere carried out on fresh samples. Soil pi l was measured on the fresh and air-dried sampleson suspension of 1 par

soil in 2.5 parts water and 0.01 M CaCl₂ solutior

Pulau

Pu«o u Plnong

Pulau

Katom

Pulou

Kiong

Pulou

Tango

Pulou Cha Mat Z in

Pulou Coray

P Tlomon

o

Singopura

Scalę

--1

0    200 km

ftg J: A Map aJPrmnsular Malaysia shounng the position of Pulau Lumut

A detailed soil survey was carried out by the Department of Agriculture, Malaysia (in collabora-tion with the Department of Soil Science, Univcrsiti Pertanian Malaysia) in order to map soil distribution in the island. I hesurvey was carried out using an auger. Twen ty soil profiles were dug for detailed investigation. Horizon designation ofSoil Taxo-nomy (Soil Survey Staff 1987) was adopted. Four soils(Tongkang, Sedu,Jawa and Parit Botak Series) wereidentifiedin the cultivated areas and another (Sedu silty) was identified in the newly reclaimed areas. Water table level in the study area fluctuates around a mean of50cm below the surface in the dry

month of July. Ali the soils identified in the studv

/

after 1 h ofintermittentshakingand an overnight stand. Electrical conductivityof the air-dried samples was measured in a suspension of soil in water at 1:5 ratio after 1 h of intermittent shaking and an overnight stand. CEC was determined by the NHjOAc method buffered at pH 7 (Chapman 1965). Basic cations were determined from the NH jOAc extracts; Ca and Mg were determined b' atomie absorption spectrophotometry, while Na and k were determined by flame photometry. Al was extracted by 1 M KC1 and determined co-lorimetrically (Barnhisel and Bertsch 1982). Free iron was determined by the method of Mehraand Jackson (1960). Particie size distribution wat

44

PERTAN1KA VOL. 14 NO.I. 1991