renched soil three feet deep is better than one of any less
depth. We all know that Indian corn, in a dry soil, sends down its
rootlets two feet or more, as well as most of the grasses. Cobbett says:
"The lucerne will send its roots thirty feet into a dry bottom!" The
Chinese yam, recently introduced, grows downward two or three feet. The
digging of an acre of such a crop, by the way, on New England soil
generally, would require a corps of sappers and miners, especially when
we consider that the yam grows largest end downward. However, the yam
may prove a valuable acquisition to the country. Every inch of
additional soil gives 100 tons of active soil per acre.

Says Mr. Denton:

"I have evidence now before me, that the roots of the wheat plant,
the mangold wurzel, the cabbage, and the white turnip, frequently
descend into the soil to the depth of three feet. I have myself
traced the roots of wheat nine feet deep. I have discovered the
roots of perennial grasses in drains four feet deep; and I may
refer to Mr. Mercer, of Newton, in Lancashire, who has traced the
roots of rye grass running for many feet along a small pipe-drain,
after descending four feet through the soil. Mr. Hetley, of Orton,
assures me that he discovered the roots of the mangolds, in a
recently made drain, five feet deep; and the late Sir John Conroy
had many newly-made drains, four feet deep, stopped by the roots of
the same plants."

Mr. Sheriff Mechi's parsnips, however, distance anything in the way of
deep rooting that has yet been recorded. The Sheriff is a very deep
drainer, and an enthusiast in agriculture, and Nature seems to delight
to humor his tastes, by performing a great many experiments at his
famous place called Tiptree Hall. He stated, at a public meeting, that,
in his neighborhood, where a crop of parsnips was growing on the edge of
a clay pit, the roots were observed to descend 13 feet 6 inches; in
fact, the whole depth to which this pit had once been filled up!

_Drainage assists pulverization._ It was Tull's theory that, by the
comminution, or minute division, of soils alone, without the application
of any manures, their fertility might be permanently maintained; and he
so far supported this theory as, by repeated plowings, to produce twelve
successive crops of wheat on the same land, without manure. The theory
has received support from the known fact, that most soils ar