Types of SoilSoil is defined as the surface of the earth that serves as a natural medium for plant growth. “Soil is a combination of organic materials, mineral grains, water and gases” (Thompson & Turk, 1993, p.253). It is very important for the environment as it produces essential products and provides a fundamental ecosystem for life. In general, soils are classified into three main categories. Which are Histosols, Oxisols and Ultisols (refer to figure 1 in Appendix 1). The first soil type is Histosols. Histosols form in topical wetland climates with thick, weathered organic soils (greater than 20% organic materials by mass) or peaty soils (Bouwman, 1990). According to Histosol (n.d.), organic soils are formed by the accumulation of partially decomposed organic matter in waterlogged conditions of peat bogs, heaths and bogs. In this way the accumulation of plant and animal residues and their decomposition products are preserved, resulting in a high organic content in the soil. They are lightweight, have extremely high water holding capacity (WHC), and have high cation exchange capacity (CEC), and appear dark in color (University of Hawai'i, 2014). According to Grozav and Rogobete (2010), who studied Romanian soil, histosols have high compressibility, low bulk density and high decay rate during drainage. According to Kim (2000), thick and abundant deposits usually form in a waterlogged environment, where conditions are good. There are problems of lowering the level of the soil surface caused by natural drainage, where "continuous decomposition of organic substance caused by better aeration" (Kim, 2000, pp. 23-24). Since Histosols have very low bulk density values, it may be necessary to compact them in or... in the center of the paper... in order to obtain the yellow to red soil color (University of Hawaii, 2014) . Ultisols is considered low activity or low fertility due to its acidic condition and low basic state. However, it usually contains clay that is non-sticky and very workable (University of Hawai'i, 2014). Bouwman (1990) stated that ultisols often have high aluminum saturation and that cation exchange capacities (CECs) are saturated with less than 35% base cations. Although they have low nutrient availability, with proper liming, addition of organic matter, application of fertilizers and proper management, these soils can be productive agricultural lands in Malaysia (Kim, 2000). In conclusion, there are three main types of soil and they differ by the region in which they are formed and its pedological structure associated with the soil environments.