Search results
Results From The WOW.Com Content Network
Soil, also commonly referred to as earth, is a mixture of organic matter, minerals, gases, liquids, and organisms that together support the life of plants and soil organisms. Some scientific definitions distinguish dirt from soil by restricting the former term specifically to displaced soil. Soil measuring and surveying device
Parent material is the underlying geological material (generally bedrock or a superficial or drift deposit) in which soil horizons form. Soils typically inherit a great deal of structure and minerals from their parent material, and, as such, are often classified based upon their contents of consolidated or unconsolidated mineral material that has undergone some degree of physical or chemical ...
Earthworms, for example, passively and mechanically alter the nature of soil environments. The bodies of dead worms passively contribute mineral nutrients to the soil. The worms also mechanically modify the physical structure of the soil as they crawl about (bioturbation) and digest on the molds of organic matter they pull from the soil litter.
When the organic component of a soil is substantial, the soil is called organic soil rather than mineral soil. A soil is called organic if: Mineral fraction is 0% clay and organic matter is 20% or more; Mineral fraction is 0% to 50% clay and organic matter is between 20% and 30%; Mineral fraction is 50% or more clay and organic matter 30% or ...
In classical [1] soil science, humus is the dark organic matter in soil that is formed by the decomposition of plant and animal matter. It is a kind of soil organic matter. It is rich in nutrients and retains moisture in the soil. Humus is the Latin word for "earth" or "ground". [2]
Soil fauna break plant residues into non-compact, loose arrangements mainly constituted of faunal droppings, which make up friable Fz horizons in moders. [6] The moder order, like mors, accumulates organic matter above the mineral horizons. [6] Fungal mycelia are reasonably expected, and plant residues may appear somewhat matted.
The mineral material from which a soil forms is called parent material. Rock, whether its origin is igneous, sedimentary, or metamorphic, is the source of all soil mineral materials and the origin of all plant nutrients with the exceptions of nitrogen, hydrogen and carbon.
The term comes from humus, which in turn comes from the Latin word humus, meaning "soil, earth". [1] Humic substances represent the major part of organic matter in soil , peat , coal , and sediments , and are important components of dissolved natural organic matter (NOM) in lakes (especially dystrophic lakes ), rivers, and sea water .