natural body consisting of layers that are primarily composed of minerals

Soil (terra, dirt, and, as applicable, land and ground) is a mixture of organic matter, minerals, gases, liquids, and organisms that together support life. The Earth's body of soil is the pedosphere, which has four important functions: it is a medium for plant growth; it is a means of water storage, supply and purification; it is a modifier of Earth's atmosphere; it is a habitat for organisms; all of which, in turn, modify the soil.


  • The soil is the great connector of our lives, the source and destination of all.
  • Es giebt ja in der ganzen Natur keinen wichtigeren, keinen der Betrachtung würdigeren Gegenstand und wenn ein berühmter Philosoph und Staatsmann der Vorzeit (Cic. de off. I. 42.) den Ackerbau für das würdigste Geschäft eines freien Bürgers erklärt, so muß es auch ein ebenso würdiges Geschäft für ihn sein, sich mit dem Boden bekannt zu machen, ohne welchen kein Ackerbau denkbar.
    • There is no more important object in nature, no object more worthy of contemplation, and if a famous philosopher and statesman of the past declares agriculture to be the worthy business of a free citizen (Cic. de off. I. 42.) it would also be an equally worthy business for him to get acquainted with the soil, without which agriculture is not conceivable.
      • Friedrich Albert Fallou (1862) Pedology or General and Special Soil Science Prospectus, Dresden 1862. [1]. Translation by Google Translate
        • Omnium autem rerum, ex quibus aliquid adquiritur, nihil est agri cultura melius, nihil uberius, nihil dulcius, nihil homine libero dignius.
          • 'For of all gainful professions, nothing is better, nothing more pleasing, nothing more delightful, nothing better becomes a well-bred man than agriculture'
            • Cicero De officiis (On Dutiable Action). Book I, Section 42. Translation by Cyrus R. Edmonds (1873), p. 73
  • Worldwide, pharmaceutical use has been on the increase for the past century and will continue to increase into the future with the development of new medicines to cure recently discovered diseases as well as previously untreatable conditions. Following use by the patient, active pharmaceutical ingredients (APIs) and their metabolites are excreted to the sewerage system. They are then typically transported to a wastewater treatment works, where, depending on their molecular structure and physicochemical properties, they can be either degraded by biological treatment processes or released to the environment in effluents or sorb to sludge. The soil environment will therefore be exposed to APIs and their metabolites when sludge from treatment processes is applied to land as an agricultural fertilizer or when soil is irrigated with reclaimed wastewater effluent. While only a few studies have explored the occurrence of APIs in the soil environment, available data indicate that a range of API classes, including nonsteroidal anti-inflammatory drugs, antidepressants, anticonvulsants, and antibacterial agents do occur in soils in concentrations up to the low mg/kg level.
    Because of detection of pharmaceuticals in soils, concerns have been raised over the potential for these substances to be taken up into human food items and to pose a risk to human health. A number of studies have demonstrated the uptake of pharmaceuticals used in human and veterinary medicine into plants. Studies have explored the uptake and translocation of a variety of APIs with a particular focus on the antidepressant drug fluoxetine and antibacterial chemicals including sulfamethazine, sulfamethoxazole, and trimethoprim into numerous plant species including root and shoot crops such as soybean, lettuce, and carrot.
  • Man has only a thin layer of soil between himself and starvation.
    • Bard of Cincinnati; reported as unverified in Respectfully Quoted: A Dictionary of Quotations (1989).
  • There is no such thing as a dead soil The decomposition of organic matter in soil is a physiological process associated with the life activities of innumerable microscopic soil inhabitants.
  • We are able to breathe, drink, and eat in comfort because millions of organisms and hundreds of processes are operating to maintain a liveable environment, but we tend to take nature's services for granted because we don't pay money for most of them.
  • The fate of the soil system depends on society's willingness to intervene in the market place, and to forego some of the short-term benefits that accrue from 'mining' the soil so that soil quality and fertility can be maintained over the longer term.
    • Eugene Odum (1993) Ecology and our endangered life-support systems. p. 143
  • The Nation that destroys its soil destroys itself.
    • Franklin D. Roosevelt, Letter to all State Governors on a Uniform Soil Conservation Law (26 February 1937)
  • We travel together, passengers on a little spaceship, dependent on its vulnerable reserves of air and soil; all committed, for our safety, to its security and peace; preserved from annihilation only by the care, the work and the love we give our fragile craft.
    • Adlai Stevenson, Speech to the UN Economic and Social Council, Geneva, Switzerland (9 July 1965).
  • To increase materially the productivity of the soil, it must be more effectively fertilized by artificial means. The question of food-production resolves itself, then, into the question how best to fertilize the soil. What it is that made the soil is still a mystery. To explain its origin is probably equivalent to explaining the origin of life itself. The rocks, disintegrated by moisture and heat and wind and weather, were in themselves not capable of maintaining life. Some unexplained condition arose, and some new principle came into effect, and the first layer capable of sustaining low organisms, like mosses was formed. These, by their life and death, added more of the life sustaining quality to the soil, and higher organisms could then subsist, and so on and on, until at last highly developed plant and animal life could flourish. But though the theories are, even now, not in agreement as to how fertilization is effected, it is a fact, only too well ascertained, that the soil cannot indefinitely sustain life, and some way must be found to supply it with the substances which have been abstracted from it by the plants. The chief and most valuable among these substances are compounds of nitrogen, and the cheap production of these is, therefore, the key for the solution of the all-important food problem. Our atmosphere contains an inexhaustible amount of nitrogen, and could we but oxidize it and produce these compounds, an incalculable benefit for mankind would follow.
    Long ago this idea took a powerful hold on the imagination of scientific men, but an efficient means for accomplishing this result could not be devised. The problem was rendered extremely difficult by the extraordinary inertness of the nitrogen, which refuses to combine even with oxygen. But here electricity comes to our aid: the dormant affinities of the element are awakened by an electric current of the proper quality. As a lump of coal which has been in contact with oxygen for centuries without burning will combine with it when once ignited, so nitrogen, excited by electricity, will burn.
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