Loess Soils, Adobe Soils, Salt Marsh Soils
Loess soils
The name "loess" is applied chiefly to large areas of soils that
have been carried to their present resting places by water or wind, and which show no
layers, being of the same nature throughout. The largest deposit of loess soils in the
United States is the alluvial loess of the great Mississippi Valley, including thousands
of square miles of the "prairie" soil of the central states. They are found in southern
Michigan, Ohio, Illinois, Indiana, Iowa, Kansas, Oklahoma, Tennessee, Arkansas, Missouri,
Kentucky, Alabama, Mississippi, Louisiana. Smaller areas of alluvial loess soils are found
in the valleys of the Connecticut, Ohio, and other rivers; while wind-formed loess soils
are found in California, Washington, Oregon and many other western states. There are
large deposits in the valley of the Rhine, the famous steppes of Russia and the inland
plains of China.
Loess soils are noted for their great depth and remarkable fertility. In China they have
produced bountiful crops for over three thousand years, with little apparent diminution
of fertility. The richness of our own loess lands in the central West is well known.
There the soil is from 5 to 150 feet deep. Although loess soils may differ very widely
chemically, they are all about the same physically — a fine silt or clay, possessing
great tenacity. Most of the loess soil of the West contains from 55 to 15 per cent, of
silt and from 6 to 15 per cent, of clay.
Adobe soils
These peculiar soils are found only in the arid West, especially
in Utah, Arizona, southern California, New Mexico, western Texas, and in the elevated
valleys of Colorado and New Mexico. They consist very largely of clay and silt, partly
worn down from surrounding high land and partly blown there from elsewhere. They are
exceedingly sticky when wet and bake very hard when dry, so that they are used for
building purposes. This makes them very hard to work; in short, they are aggravated clay
soils. When they are wet enough they are remarkably productive, as they are unusually
rich in plant food. Some adobe soils are very deep — those in some of the valleys of the
arid regions being over 2,000 feet deep. Adobe soils are usually light buff or gray,
except when they contain a considerable quantity of humus, which makes them darker. They
are very fine grained; no grit is felt when adobe is rubbed between the fingers. The
depth, fineness and virginal fertility of adobe soils, since they have lost very little
from leaching, makes them wonderfully productive. These soils are quite similar to the
loess soils of the Central West.
Salt marsh soils
All along the Atlantic Coast, and especially in New England,
are thousands of acres of marsh land that some day will be used for farm crops. They are
made largely from soil that has been worn by the sea from the rocks on the coast. Each
wave that curls its crest over the "stern and rockbound coast" wears it away to some
extent, as is witnessed by the honeycombed rocks at Marblehead and elsewhere. The
headlands that project into the sea are worn down and strewn upon the beach as sand. Each
wave that comes tumbling in grinds these rock particles a little finer — we can hear them
rustle and grind against each other in the undertow. After a while the coarse sand of the
beach becomes fine sand or mud; it may then be carried out to sea by the undertow or
deposited along the inlets and bays by coastwise currents. The latter case marks the
beginning of a salt marsh soil. As soon as it gets fairly well started, though still
covered with water, the soil is occupied with a dense growth of eel-grass. This
accumulates more soil; sea weed, dead fish and other refuse collect and the soil thickens
rapidly. Finally it is raised above the tides and the eel-grass gives place to other
grasses which slowly extend to the beach over the mud flats. In the course of time
farmers cut from these flats "salt hay," which is much relished by cattle.
All salt marshes are likely to be overflowed occasionally. It is necessary to drain them
thoroughly and to prevent the overflow of salt water by diking before they can be used
for ordinary farm crops, which object to so much salt in the soil. It is stated that
there are over 200,000 acres of very rich salt marsh land between New York City and
Portland, Me., which would be worth $20,000,000 if reclaimed; and that there are
3,000,000 acres on the entire Atlantic Coast that could be reclaimed. The cost of diking
and draining these lands should not be over $50 per acre. A considerable area of salt
marsh soils has already been reclaimed. Salt marsh soils are particularly valuable for
growing grass, onions, cabbage, celery; where they contain a large amount of muck
cranberries are successful.
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