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:
“Green, green is El Aghir. It has a railway station,
And the wealth of its soil has borne many another fruit:
A mairie, a school and an elegant Salle de Fetes.
Such blessings, as I remarked, in effect, to the waiter,
Are added unto them that have plenty of water.”
—Norman Cameron (b. 1905)
“And what if all of animated nature
Be but organic Harps diversely framed,
That tremble into thought, as o’er them sweeps
Plastic and vast, one intellectual breeze,
At once the Soul of each, and God of all?”
—Samuel Taylor Coleridge (1772–1834)
“What does it matter how one comes by the truth so long as one pounces upon it and lives by it?”
—Henry Miller (1891–1980)