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:
“I love, cherish, and respect women in my mind, in my heart, and in my soul. This love of women is the soil in which my life is rooted. It is the soil of our common life together. My life grows out of this soil. In any other soil, I would die. In whatever ways I am strong, I am strong because of the power and passion of this nurturant love.”
—Andrea Dworkin (b. 1946)
“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)
“Roughly speaking, any man with energy and enthusiasm ought to be able to bring at least a dozen others round to his opinion in the course of a year no matter how absurd that opinion might be. We see every day in politics, in business, in social life, large masses of people brought to embrace the most revolutionary ideas, sometimes within a few days. It is all a question of getting hold of them in the right way and working on their weak points.”
—Aleister Crowley (1875–1947)