much as your most common cultivated land, and even twice as much as
your level upland soil, which you consider too poor for farming, but
in which phosphorus and not nitrogen must be the first limiting
element, the same as with ours.

The fact is that the nitrogen problem in the East was one of the
reasons why we have chosen to locate in Southern Illinois. I am
confident that the level lands I saw about Blairville and over in
Maryland are more deficient in organic matter and nitrogen than your
uncultivated level upland, and probably even more deficient than
your common gently sloping cultivated lands, because of your long
rotation with much opportunity for nitrogen fixation by such legumes
will grow in your meadows and pastures, including the red clover
which you regularly sow, the white clover, which is very persistent,
and the Japan clover, which it seems to me has really benefited you
more than the others.

To me a difference in nitrogen content of two thousand pounds per
acre signifies a good deal. It plainly signifies a hundred years' of
"working the soil for all that's in it," beyond what has yet been
done to our "Egypt." The cost of two thousand pounds of nitrogen in
sodium nitrate would be at least $300 and even that would not
include the organic matter, which has value for its own sake because
of the power of its decomposition products to liberate the mineral
elements from the soil, as witness the most common upland soils of
St. Mary county, Maryland, with a phosphorus content reduced to one
hundred and sixty pounds per acre in two million pounds of the
ignited soil. The ten-inch plows of Maryland, the twelve-inch of
Southern Illinois, the fourteen-inch of the corn belt, and the
sixteen-inch of the newer regions of the Northwest, signify