Soil Definition Of Soil

Soil Definitions

Soil is a combination of minerals, organic matter, gases, liquids, and various organisms that come together to support life on Earth (Gupta, 2015). Buol et al., (2011) described it as a tiny layer of material on the surface of the earth, which are made up a lot of things, such as weathered rock and decomposed plant and animal matter. Doran and Parkin, (1994) referred to it as the unconsolidated mineral or organic material on the direct surface of the earth that serves as a natural medium for the growth of land plants. Wild (1993), described as loose material composed of weathered mineral and other materials alongside partially decayed organic matter that covers large part of the land surface of the earth. While Gilluly et

The organic matter content of soils usually ranges between 2-5% or at times it may be less than 2% (Nelson and Sommers 1996). Organic matter that is partially decomposed in the soil is referred to as humus, and these are formed in the process whereby most of the cellulosic material disappears; lignins are transformed while proteins are retained. Although organic matter typically makes up a small percentage of most mineral soils (less than 10 percent by weight), it is very important because it positively influences or modifies the effects of almost all soil properties (Bauer and Black

In temper¬ate regions of the world where decomposition is slow, plenty of organic debris collects in the soil, whereas in tropical and subtropical regions, warm and humid conditions cause quick decomposition and mineralization of organic matter (Nelson and Sommers 1996)

(iii) Soil water/moisture obtained from atmosphere and reactions in the soil (chemical, physical and microbial). Water is another primary component of soil that can make up approximately 2% to 50% of the soil volume (Nelson and Sommers 1996). It is essential for transporting nutrients to growing plants and soil organisms and also for aiding both biological and chemical decomposition. Availability of soil water is the capacity of a particular soil to hold water that is available for plant use (Gardner et al., 2000).

Soil water is important for three special reasons:

• Water availability is essential for all life on earth; this includes lives of plants and organisms in the soil (Gardner et al.,