Saturday, November 6, 2010

Be Careful What You Post

Someone made a mistake of saying on croptalk that Ohio was covered with trees before man and had 1-2 inches of topsoil. I think he claimed our productive soil was due to years of plowing!

You know it only takes a few minutes to see that Ohio and the midwest soil was formed by glaciers. Everything that has happened since has affected what we have today but it all started with the Big White Plow.

Soil Regions 1 through 8 represent the portion of Ohio that was covered by glacial ice during one or more glaciations. That is the gray part of the picture. Most people think that IS Ohio. The most common soils in these regions formed in glacial deposits. The older glacial deposits are in Regions 7 and 8. Most of the soils in the glaciated part of the state are very deep to bedrock.

The most common soils in Regions 9 through 12 formed in materials weathered from sedimentary rocks. Because soil forms more slowly from bedrock than from unconsolidated glacial material, soils in Regions 9 through 12 tend to be more shallow to bedrock than soils in Regions 1 through 8. Weathered rock, that is good for pature, trees and hiking!

Soil Regions 1, 3, 4, 7 and 9 occur in the part of Ohio where limestone, dolomite and limy shales are the most common bedrocks, and so the soils in these regions tend to have a relatively high lime content in the substratum. The glacial deposits in Regions 2, 5, 6, and 8 have a lower lime content. In most of Regions 10, 11 and 12 the soils formed in materials weathered from acid sedimentary rocks, mainly sandstone, siltstone and shale. Remember dolomite is magnesium rock and calcitic rock is high in calcium. Most of Ohio is Dolomitic rock formed.

Soils naturally become more acid over time under Ohio's weather conditions, but soils with lime in the substratum are neutral or only slightly acid in part of the subsoil. Since most plant nutrients are chemically active under neutral or slightly acid conditions, soils with more lime in the substratum are generally more fertile for crop production. Ohio farmers commonly increase crop yields by spreading lime to neutralize the acidity of the topsoil and the upper part of the subsoil.
Ohio is a pretty neat state for many reasons. It's location in the midwest, mid-atlantic and the way it was formed makes it the neat state it is.
Tomorrow I will introduce you to a friend who will write this page while we take a little sabbatical.
Be Careful What You Post!

1 comment:

  1. Natural history museums often have the skeletal remains of Ice Age mammals. They are enough to inspire awe in part because many of the species alive during that time were much bigger than modern animals. The Ice Age was a time of giant deer and moose, with a species of beaver as large as a modern black bear.

    In short, it was a time not long ago with a climate and ecology so different it intrigues both geologists and school children.

    Imagine my pleasure, then, when I recently got to hold a sample of 16,000 year old woolly mammoth poop from the Ice Age. Talk about an intimate connection with the past!

    Ancient poop is known to geologists as coprolite material. It can be truly fossilized as solid rock, or just preserved in glacial ice, permafrost or dry caves. One geology department softball team I knew proudly named itself the "Coprolites." Such is geologic humor.

    Ancient mammoths and other prehistoric animals were well defined by the phrase, "you are what you eat." And by studying what ancient animals ate - through their intestinal remains or their poop - we can learn about their diets and nutrition.

    Bruce Davitt of the Dept. of Natural Resource Sciences at Washington State University has the habit of studying ancient and modern poop - and deducing from it important clues to animal habits and environments. In one case he looked at caribou dung found in a permanent snow patch in southern Yukon, outside of Whitehorse. Caribou haven't been present in the area since the 1800s, so obviously the dung was at least that old. But using radioactive-dating techniques, researchers found the dung was about 2400 years old.

    "We looked at the material under the microscope and compared plant fragments in the fecal pellets to the plants of that environment," he said. "We determined the dung reflected caribou's spring or summer diet."

    It's possible the caribou sought out the cool temperatures of the permanent ice patch in the warmth of the Arctic summer, either for the temperature change alone or to get away from the bugs that are thicker than pea soup in that part of the world.

    The permanent snowfield also yielded part of an arrow shaft which was dated as about 4400 years old, making it a rare example of hunting technology from that era found in Canada.

    Davitt has also worked on much more recent fecal material and deduced something crucial to the health of some langur monkeys in the Bronx Zoo.

    As Davitt explains it, several monkeys in the Bronx had mysterious developed cases of peritonitis. The zoo sent Davitt samples of the animals' intestinal products to check for what could be contributing to their life-threatening illness.

    "The vet there at first thought it might be that the monkeys were eating rope that was in the exhibit," Davitt said. "But monkeys have a strong sense of social order. The higher-ups on the scene got to eat the monkey food the zoo provided while lower-downs waited nervously on the side."

    That led the less fortunate monkeys to eat fronds of a plant called Pandanus utilis that was in the exhibit.

    "We found the plant in the fecal material. There were microscopic crystals on the plant fibers, and those crystals were rubbing on the monkey's intestines," Davitt said.

    That insight helped save the lives of the monkeys after the plant was removed from their environment.

    "We're just a small part of much bigger teams, helping researchers elsewhere engaged in their studies of wildlife," Davitt said.

    One simple piece of equipment in Davitt's lab is a kitchen blender. It's used to pulverize samples into a thin soup from which slides can be made for examination under the microscope.

    Peters can be reached at