Search results
Results from the WOW.Com Content Network
Carbon, as it relates to the organic matter of soils, is a major component of soil and catchment health. Several factors affect the variation that exists in soil organic matter and soil carbon; the most significant has, in contemporary times, been the influence of humans and agricultural systems.
The pool of organic carbon exists in dynamic equilibrium between gains and losses; soil may therefore serve as either a sink or source of carbon through carbon sequestration or greenhouse gas emissions, respectively, depending on exogenous factors.
Soil gases (soil atmosphere [1]) are the gases found in the air space between soil components. The spaces between the solid soil particles, if they do not contain water, are filled with air. The primary soil gases are nitrogen, carbon dioxide and oxygen. [2] Oxygen is critical because it allows for respiration of both plant roots and soil ...
Organic carbon held in soil is eventually returned to the atmosphere through the process of respiration carried out by heterotrophic organisms, but a substantial part is retained in the soil in the form of soil organic matter; tillage usually increases the rate of soil respiration, leading to the depletion of soil organic matter. [24]
Particulate organic matter (POM): is the organic matter that retains evidence of its original cellular structure, [18] and is discussed further in the next section. Humus: is usually the largest proportion of organic matter in soil, contributing 45 to 75%. Typically it adheres to soil minerals, and plays an important role structuring soil.
The plant remains have left the soils rich with carbon, although as drainage exposes the soils to oxygen the organic material can break down, releasing the carbon into the atmosphere. The process ...
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 ...
Soil respiration is a key ecosystem process that releases carbon from the soil in the form of carbon dioxide. Carbon is stored in the soil as organic matter and is respired by plants, bacteria, fungi and animals. When this respiration occurs below ground, it is considered soil respiration. Temperature, soil moisture and nitrogen all regulate ...