Vicksburg National Military Park
Loess Soil Mystifies Some Visitors
National Park Service U.S. Department of the Interior Vicksburg National Military Park
Compacted Dust
Most visitors to the Vicksburg area spend their time looking around instead of down. But those who do examine the area's soil are usually seeing something they've never seen before. Loess (pronounced low-ess) soil is what composes Vicksburg's hills. It is a low-clay, low-sand soil that is the consistency of compacted dust -- because that's what it is. Geologists think that swirling storms in prehistoric days ended with the deposits concentrated here. The only other place in the world with as much of the same type soil is in China.
To Escape the Relentless Shelling
A tip-off to the unusual soil is provided when visitors notice roadsides with perpendicular cuts instead of slopes. The engineering reason behind this is simple. Loess soil is fairly stable when cut at 90 degree angles, but washes badly if it isn't -at least until grass or other vegetation is rooted. Loess is the most important geologic deposit in the Vicksburg area because almost all highway and facility construction activities occur within it. Loess is a unique geologic deposit consisting almost entirely of silt-sized grains dominated by the mineral, quartz. The loess is capable of sustaining steep slopes as high as 100 ft under certain conditions. But once it has been disturbed, loess becomes highly erodible by water, forming deep gullies and pipes. Extensive new construction along the Mississippi riverfront at Vicksburg has required concerted reinforcing and stabilization efforts to prevent movement of the bluffs along a prominent failure scarp. The historical town of Grand Gulf, 20 miles south of Vicksburg, was abandoned because erosion of the loess bluffs destroyed the town site.
The loess deposits are, of course, the core of the city's natural defenses and made the area attractive to French and Spanish settlers. Later, Vicksburg's defenders during the Civil War had such a natural advantage that conquering the city could not be achieved by a direct assault, despite the fact Rebel forces were greatly outnumbered. To escape relentless shelling from Federal artillery during the 47-day siege, many citizens of Vicksburg took refuge underground, digging caves into hillsides of loess soil. Single family caves had only one or two rooms, while others were huge and accommodated as many as 200. To avoid entrapment and induce air circulation caves often had several entrances. Time and modern earth-moving equipment have leveled a lot of the area's hills and gullies -- but much of the natural terrain remains. It is especially visible during a tour through the Vicksburg National Military Park.
Model of cave used during the siege of Vicksburg.
Kurse of the Kudzu
(Extracted from an article By Lucile Bayon Hume printed in River Cities, September 1992.)
"Why in heaven's name," one might ask, "would anyone want a land-hungry vine badly enough to cultivate it when we can't stop the stuff from growing?" But the U.S. wanted kudzu once, introducing the plant from Japan at the 1876 Centennial Exposition in Philadelphia. After C.E. Pleas of Chipley, Florida, planted a field of kudzu proving it would thrive in our climate, the country welcomed it with open arms as a savior of our soil. Because kudzu weaves a sturdy web of root systems which act as a net to hold dirt in place, and, at the same time, enriches the soil with a nitrogen- fixing bacteria, the luxuriant foliage seemed to be the answer to both farmers' and landowners' prayers to preserve a land not only deeply cut by gullies and ravines, but from the rapacious appetite of Ole Man River' for bluffs and banks which periodically slide into his waters.
Land-Hungry Vine
The government actually planted kudzu in a soil conservation effort and committed the classic crime of hubris (i.e., overbearing pride or presumption, arrogance), which was the traditional downfall of mankind in ancient Greek tragedy. In the classical theater, when man took things into his own hands and thumbed his nose at the gods, the dieties of Olympus got together and came up with suitable punishment to put the offender in his place. In this case, man messed with Mother Nature, and she got the South back with a vengeance -- kudzu is the vine that ate the South, compliments of Mother Nature. It may grow sixty feet in length in one season. Its roots may reach a depth of eight feet and have a circumference of three inches. Give it an inch, and it will take a county. Imagine one long, insignificant plant in a pasture. Kudzu, a member of the legume family, resembles soybeans or cow peas and when it blooms has reddish purple flowers that are the image of those of the common garden bean. But when no one is looking, kudzu slips its long tentacles into the soil, silently consuming more and more acreage. The roots of the plant are jointed, and, at each joint, branches of two to four feet reach upwards and become separate, independent plants as the stems between the rooted joints die. One plant produces armies of new plants which in turn produce their own armies which march across the South, devouring telephone poles, swallowing trees, burying junkyards and smothering vacant buildings. As kudzu creeps, it leaves behind it a trail of vine-covered figures that look as if a topiary artist has run wild. Telephone and electrical companies, however, are not amused. Kudzu has no respect for cables and transformers and no concern for the power outages it causes. When the kudzu shinnies up telephone
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and power line poles, service problems are imminent. If not actually weighing down and stretching the wires, kudzu will literally smother a transformer. The moisture retained in the leaves after a rain, or even a heavy dew, will affect the efficiency of a transformer and cause power surges, so even if service is not completely interrupted, electrical equipment may be damaged. Kudzu has made the rounds in agricultural and horticultural books, going from desirable listings following its introduction, to now being listed under pests and weeds. Once established, it is next to impossible to get rid of without killing every other green and growing thing in the vicinity. Chopping is ineffective, since the roots are still productive. Digging is effective, but with roots eight feet deep, a lot of digging is required. Since kudzu is essentially a woody plant when its stems and runners mature, chemicals which kill it also kill trees as well. And of course, burning kudzu will destroy the surrounding vegetation. Kudzu was traditionally used for treatment of gastrointestinal maladies, circulation problems and headaches, and currently is used in China to treat cardiovascular diseases. In Japan, tea made from kudzu has long been used for alleviation of complaints ranging from muscle aches to allergic reactions and congestive disorders, including asthma and sinusitis. In the U.S., we are able to acknowledge the fact that kudzu is good for the soil and recognize the fact that horses and cows adore it as a high protein feed. It is also of value as a mulch, but these attributes do not outweigh the aggravation it causes.