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A hydric soil is defined by federal law [4] to mean "soil that, in its undrained condition, is saturated, flooded, or ponded long enough during a growing season to develop an anaerobic condition that supports the growth and regeneration of hydrophytic vegetation".
Soil may be regarded as waterlogged when it is nearly saturated with water much of the time such that its air phase is restricted and anaerobic conditions prevail. In extreme cases of prolonged waterlogging, anaerobiosis occurs, the roots of mesophytes suffer, and the subsurface reducing atmosphere leads to such processes as denitrification ...
Anaerobic digestion occurs naturally in some soils and in lake and oceanic basin sediments, where it is usually referred to as "anaerobic activity". [ 2 ] [ 3 ] This is the source of marsh gas methane as discovered by Alessandro Volta in 1776.
Soils in freshwater marshes are considered hydric; soils that are saturated during the growing season and have anaerobic, or no oxygen, conditions due to the saturation. [12] The soils in freshwater marshes have high organic matter due to slow decomposition rates and are often black or brown.
Obligate anaerobes are found in oxygen-free environments such as the intestinal tracts of animals, the deep ocean, still waters, landfills, in deep sediments of soil. [9] Examples of obligately anaerobic bacterial genera include Actinomyces, Bacteroides, Clostridium, Fusobacterium, Peptostreptococcus, Porphyromonas, Prevotella ...
This allows anaerobic conditions to prevail and depress aerobic microbial activity. Studies have shown that soil moisture only limits respiration at the lowest and highest conditions with a large plateau existing at intermediate soil moisture levels for most ecosystems. [10]
Nitrogen fertilizer being applied to growing corn in a contoured, no-tilled field in Iowa.. Nutrient management is the science and practice directed to link soil, crop, weather, and hydrologic factors with cultural, irrigation, and soil and water conservation practices to achieve optimal nutrient use efficiency, crop yields, crop quality, and economic returns, while reducing off-site transport ...
The rows formed slow surface water run-off during rainstorms to prevent soil erosion and allow the water time to infiltrate into the soil. Soil conservation is the prevention of loss of the topmost layer of the soil from erosion or prevention of reduced fertility caused by over usage, acidification, salinization or other chemical soil ...