Word: soils
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Dates: during 1950-1959
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...first steps was to get copies of a photographic air survey that Britain's Royal Air Force made of southern Etruria during World War II. Studied carefully, the photos often show hundreds of shadowy circles. These are Etruscan tombs, which affect slightly the fertility of the soil and therefore the darkness of the chlorophyll in green plants growing on the surface. When air photos are taken after a light snowfall, the tombs often show up as snowy patches surrounded by dark ground where the snow has melted...
Look, Then Dig. Next step was to drive metal stakes in the ground about 15 ft. apart, send a weak electric current between them, and measure in this way the electrical resistance of the soil. Since the air space of a tomb raises the resistance and the filled-in earth at its entrance lowers the resistance, a few readings often tell the diggers exactly where...
...ambitious young idealist comes to Washington with An Idea. A humanitarian botanist, he has developed a new kind of soil in which vegetables grow to enormous size. He merely needs a rather amusing ingredient. "I turn gold into dirt," he explains. And, not only as the central issue for a comedy, this is quite a pleasant idea...
Most of the strontium 90 created by past bomb tests is still in the stratosphere or in the soil, but it will tend to move for years into human bones. If no more large tests are made, the Columbia men figure, the average human bone should contain, by 1970, about 1.3 micromicrocuries of strontium 90 per gram of calcium. This is eleven times the present amount...
...Columbia men are concerned about such individuals as the Vancouver man who have a lot more strontium 90 than the average, and about people who get most of their calcium from vegetables that were grown in calcium-deficient soil. Such people may come much closer to the "permissible" level. The permissible level itself is still considered debatable. It was derived principally from a small amount of experience with the cancer-causing effects of radium in the bones; at that time no strontium 90 existed in the world. When more is known, the permissible level for strontium 90 may have...