Geochemical Properties of Peat Soil in Sarawak - A Review

Abstract

In geotechnical field, peat soil is defined as soil which is formed by accumulation of purely one hundred percent organic matter and which the distinction between soil and vegetative accumulation is not clear. The main objectives of this review paper are to summarize and compare the geochemical properties of peat soil in different districts of Sarawak. Case studies that have been chosen covered central of Sarawak up to the North of Sarawak. Geochemical properties of peat soil that being observed are pH, total carbon, organic matter, bulk density and the total nitrogen. Geochemical properties are found to be governed by the types of material inside the soil and also strongly correlated with the engineering properties of soil. Notably showed that the types of organic matter, namely fibre and/or humidified organic inside the soil will influence the soil porosity. The findings of the studies showed that geochemical properties of the peat soil in different districts of Sarawak is site dependent and could be affected by the different land use or land activities. The differences in land use and land activities affected the bulk density, pH and types of organic matter in the soil. The result indicated that peat soil land in different district can categorized as acidic soil because of the pH range is between 3.3-3.75. For the bulk density, the lowest value is recorded at the Dalat sago plantation site, which is 0.14 g/cm 3 . For the value of the total carbon, peat soil from the Laogan Bunut National Park is the lowest, 47.6%. Furthermore, total carbon is related to the soil organic matter, coincidentally the value of soil organic matter in Miri found to be the lowest which is 74.59%. Result for the total nitrogen, there are little difference between the district. Range of the total nitrogen is from 0.9% to 2.4%, Sibu site is getting the lowest value in this case.