2013 Volume 13 Issue 1 Pages 4-13
The land surface of the earth is covered by different types of soils, which are commonly considered as microcosms with ecological functions. Although the soil layer is less than 200 cm thick, soils contribute profoundly to the environmental stability of the earth, notably through the circulation of functional substances. Blackish soils, which are widely distributed in humid areas, are rich in organic matter and comprise various types of biological habitats and circulate the substances that are essential elements for all living organisms such as carbon, nitrogen, and sulfur. Although arid soils of lighter color harbor little biological activity and do not contribute much toward global circulation of essential elements, their albedo is important for maintaining the energy budget from the sun and atmospheric circulation. Therefore, soils lying anywhere on land have some great contribution for the stable maintenance of the global environment. For more than 2000 years, human beings have subsisted on foods obtained by cultivating the thin soil layer, sowing seeds, raising crops, and harvesting them. The duration of this human agricultural system indicates its acceptance as the most practical and sustainable method for obtaining food. However, our undiminished pursuit of wealth and use of soil resources has led to severe land degradation (desertification) and soil contamination globally. Once soil degradation proceeds, the global environment exacerbates its instability and decreases its ability to support a stable global ecosystem. Because of the growth in instability of these factors, the global environment may become fragile and erratic. Although scientific evidence does not yet associate the recent phenomena of extraordinary weather events with notions of global environmental decay, we must pursue sustainability through sincere discussions of local to global soil environments.
