Benefits of Soil Organic Matter and Humus
- The process that converts raw organic matter into humus feeds the soil population of microorganisms and other creatures, thus maintains high and healthy levels of soil life.
- The rate at which raw organic matter is converted into humus promotes (when fast) or limits (when slow) the coexistence of plants, animals, and microbes in soil.
- Effective humus and stable humus are further sources of nutrients to microbes, the former provides a readily available supply, and the latter acts as a longer-term storage reservoir.
- Decomposition of dead plant material causes complex organic compounds to be slowly oxidized (lignin-like humus) or to break down into simpler forms (sugars and amino sugars, aliphatic, and phenolic organic acids), which are further transformed into microbial biomass (microbial humus) or are reorganized, and further oxidized, into humic assemblages (fulvic and humic acids), which bind to clay minerals and metal hydroxides. There has been a long debate about the ability of plants to uptake humic substances from their root systems and to metabolize them. There is now a consensus about how humus plays a hormonal role rather than simply a nutritional role in plant physiology.
- Humus is a colloidal substance, and increases the soil's cation exchange capacity, hence its ability to store nutrients by chelation. While these nutrient cations are accessible to plants, they are held in the soil safe from being leached by rain or irrigation.
- Humus can hold the equivalent of 80–90% of its weight in moisture, and therefore increases the soil's capacity to withstand drought conditions.
- The biochemical structure of humus enables it to moderate – or buffer – excessive acid or alkaline soil conditions.
- During the humification process, microbes secrete sticky gum-like mucilages; these contribute to the crumb structure (tilth) of the soil by holding particles together, and allowing greater aeration of the soil. Toxic substances such as heavy metals, as well as excess nutrients, can be chelated (that is, bound to the complex organic molecules of humus) and so prevented from entering the wider ecosystem.
- The dark color of humus (usually black or dark brown) helps to warm up cold soils in the spring.
Read more about this topic: Humus
Famous quotes containing the words benefits of, benefits, soil, organic and/or matter:
“It is too late in the century for women who have received the benefits of co-education in schools and colleges, and who bear their full share in the world’s work, not to care who make the laws, who expound and who administer them.”
—J. Ellen Foster (1840–1910)
“I do seriously believe that if we can measure among the States the benefits resulting from the preservation of the Union, the rebellious States have the larger share. It destroyed an institution that was their destruction. It opened the way for a commercial life that, if they will only embrace it and face the light, means to them a development that shall rival the best attainments of the greatest of our States.”
—Benjamin Harrison (1833–1901)
“An underground grower, blind and a common brown;
Got a misshapen look, it’s nudged where it could;
Simple as soil yet crowded as earth with all.”
—Richard Wilbur (b. 1921)
“The human face is the organic seat of beauty.... It is the register of value in development, a record of Experience, whose legitimate office is to perfect the life, a legible language to those who will study it, of the majestic mistress, the soul.”
—Eliza Farnham (1815–1864)
“Friends broaden our horizons. They serve as new models with whom we can identify. They allow us to be ourselves—and accept us that way. They enhance our self-esteem because they think we’re okay, because we matter to them. And because they matter to us—for various reasons, at various levels of intensity—they enrich the quality of our emotional life.”
—Judith Viorst (20th century)