Soil organic matter (SOM) is the organic matter component of soil. It can be divided into three general pools: living biomass of microorganisms, fresh and partially decomposed residues, and humus: the well-decomposed organic matter and highly stable organic material. Surface litter is generally not included as part of soil organic matter.
According to Troeh and Thompson's Soils and Soil Fertility, "Organic matter constitutes from 1 to 6% of the topsoil weight of most upland soils. Topsoils with less than 1% organic matter are mostly limited to desert areas. At the other extreme, the organic matter content of soils in low wet areas may be as high as 90% of more. Soils with more than 12-18% organic carbon (approximately 20-30% organic matter) are called organic soils."
Famous quotes containing the words soil, organic and/or matter:
“Weather is not as important as good soil, and good soil is not as important as human harmony.”
—Chinese proverb.
Mencius.
“The best thing about the sciences is their philosophical ingredient, like life for an organic body. If one dephilosophizes the sciences, what remains left? Earth, air, and water.”
—Novalis [Friedrich Von Hardenberg] (1772–1801)
“No face which we can give to a matter will stead us so well at last as the truth. This alone wears well.”
—Henry David Thoreau (1817–1862)