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Essay / Types of Soil Essay - 737
Types of SoilSoil is defined as the surface of the earth that serves as the natural environment for plant growth. “Soil is a combination of organic matter, mineral grains, water and gases” (Thompson & Turk, 1993, p.253). It is very important for the environment because it produces essential products and provides an essential ecosystem for life. In general, soils are classified into three broad categories. Which are Histosols, Oxisols and Ultisols (See figure 1 in appendix 1). The first type of soil is that of Histosols. Histosols form in topical wetland climates with weathered, thick organic soils (more than 20% organic matter by mass) or peaty soils (Bouwman, 1990). According to Histosol (nd), organic soils are formed by the accumulation of partially decomposed organic matter in waterlogged conditions of peatlands, heaths and swamps. Thus, accumulated residues of plants and animals and their decomposition products are preserved, leading to a high organic content in the soils. They are lightweight, with extremely high water holding capacities (WHC) and high cation exchange capacity (CEC). They also appear dark in color (University of Hawaii, 2014). According to Grozav and Rogobete (2010), who studied the soil in Romania, histosols have high compressibility, low bulk density and high decomposition rate during drainage. According to Kim (2000), in a water-saturated environment, where conditions are good, thick and large deposits generally form. There is a problem of falling ground surface level caused by natural drainage, where “continued decomposition of organic matter caused by improved aeration” (Kim, 2000, pp. 23-24). Since histosols have very low bulk density values, it may be necessary to compact them middle of paper...resulting in a yellow to red color of the soils (University of Hawaii, 2014). . Ultisols are considered to have low activity or low fertility due to their acidic state and low basic status. However, they generally contain clay that is non-sticky and very malleable (University of Hawaii, 2014). Bouwman (1990) stated that ultisols often have high aluminum saturation and cation exchange capacities (CECs) are saturated with less than 35% base cations. Although they are low in nutrient availability, with adequate liming, addition of organic matter, application of fertilizer and appropriate management, these soils can be agriculturally productive soils in Malaysia (Kim, 2000). In conclusion, there are three main types of soil. soil and they are differentiated by the region where they form and its soil structure associated with soil environments.