By Francine Lheritier, Soil Scientist, USDA-Natural Resources Conservation Service

“Most people don’t realize that just beneath our feet lies a diverse, complex, life-giving ecosystem that sustains our entire existence,” said Jason Weller, Chief of USDA’s Natural Resources Conservation Service (NRCS). To increase awareness of soils and the understanding of soils’ important functions, the United Nations and the USDA have proclaimed 2015 as the International Year
of Soil. It is difficult to rate the importance of the different soil functions, since all are vital to our well-being.

However, the function of supporting food and agriculture worldwide is fundamental for the preservation and advancement of human life on this planet. Soil is also the basis for plant growth and contributes to the maintenance of natural and planted vegetation, including our diverse forests and grass-lands and the huge breadth of crop species and varieties (annuals, perennial shrubs, and trees) that are cultivated or managed for their diverse food fiber, fodder, fuel, and medicinal products in relation to the prevailing climate, landscape and soil type, and according to societal needs.

Through plant growth, the soil also plays an important role in supporting animal biodiversity above ground, including wildlife and domesticated livestock. Moreover, the soil itself contains millions of diverse organisms that play many vital functions such as breakdown of plant debris, taking in components from the atmosphere, aerating the soil as well as regulation of carbon, nutrient and hydrological cycling and breakdown of toxic elements.

Soil is increasingly recognized as playing a fundamental role in the quality and availability of our water supply. The soil, coupled with the landscape and its vegetation, is responsible for the distribution of all rainwater falling upon it and thus plays a key role with respect to the water cycle and supply as now recognized by hydrologists.

Related to how water moves through the soil and the absorption properties of soils is the soil’s ability to perform an important function in pollution control (pesticides, nitrates etc.). Soil has always been important for the foundation platform of buildings, roads and other communications. It also provides base materials for these.

Many people are interested in their origins and how earlier man lived. Soil plays an important part in the preservation of the earth’s history and cultural heritage. Finally, soils have been recognized as having a key role in modifying and ameliorating the risks and effects of climate change. Soil organic matter is one of the major pools of carbon in the biosphere and is important both as a driver of climatic change and as a response variable to climate change, capable of acting both as a source and sink of carbon.

Sources-From the Food and Agriculture Organization