| dc.description.abstract | Soil is a natural body consisting of layers (soil horizons) that are composed of weathered mineral
materials, organic material, air and water (Bockheim et al., 2005). It is the end product of the combined
influence of the climate, relief (slope), organisms (flora and fauna), parent materials (original minerals),
and time. The most widely recognized function of soil is its support for food production. Farmers who
use soil in crop production know very well that it is the foundation for agricultural production. This is
because it is the medium in which growth of food-producing plants occurs. It supplies the plants with
nutrients, water, and support for their roots. The plants, in turn, support human and animal life with
food and energy. Soil also acts as a repository for seeds, germplasm, and genes for flora and fauna.
In general, soil is the medium for preservation and advancement of life on earth (Brady, 1984; Foth
and Ellis, 1997). Besides supplying water treatments to plants, soil also supports millions of organisms
living in it. These organisms have proven useful in medicine, biodegradation and recycling of waste, as
food, as well as being essential in the conversion of minerals and nutrients to readily useable formats
for plants and in turn animal nutrition.
In hydrology, soil interacts with the hydrosphere as a medium that absorbs, purifies, transports,
and releases water. In the hydrological cycle, the water that passes through the soil accumulates
temporarily in the form of rivers, lakes/oceans/dams, soil water, and groundwater. During the
storage process, soil filters the water against pollutants including natural and synthetic compounds.
It also acts as a buffer against natural phenomena such as floods and soil erosion. In hydrology, the
interaction of soil with the atmosphere has numerous environmental benefits. It can absorb excess
energy radiation from the sun and release it gradually. Soil’s gaseous exchanges with the atmosphere
involve carbon dioxide, nitrogen oxides and methane and are of a magnitude that has been reported to
have profound effects on the global climate. In fact, soil has been recognized as the largest terrestrial
sink for carbon dioxide and consequently has great importance in mitigating the impacts of climate
change (FAO, 2004). | en |
