mers should use fish, or guano, or
superphosphate, or nitrate of soda, and sell all the hay, and straw, and
potatoes, and root-crops, they could raise, many of our sandy soils
would soon become poor in available potash. But even in this case the
clover and beans would show the deficiency sooner than wheat or even
potatoes.

"And yet we are told," said the Deacon, "that potatoes contain no end of
potash."

"And the same is true," said I, "of root-crops, such as mangel-wurzel,
turnips, etc., but the fact has no other significance than this: If you
grow potatoes for many years on the same land and manure them with
nitrogenous manures, the soil is likely to be speedily impoverished of
potash."

"But suppose," said the Deacon, "that you grow potatoes on the same land
without manure of any kind, would not the soil become equally poor in
potash?"

"No," said I, "because you would, in such a case, get very small
crops--small, not from lack of potash, but from lack of nitrogen. If I
had land which had grown corn, potatoes, wheat, oats, and hay, for many
years without manure, or an occasional dressing of our common
barnyard-manure, and wanted it to produce a good crop of potatoes,
I should not expect to get it by simply applying potash. The soil might
be poor in potash, but it is almost certain to be still poorer in
nitrogen and phosphoric acid."

Land that has been manured with farm-yard or stable-manure for years, no
matter how it has been cropped, is not likely to need potash. The manure
is richer in potash than in nitrogen and phosphoric acid. And the same
may be said of the soil.

If a farmer uses nitrogenous and phosphatic manures on his clayey or
loamy land that is usually relatively rich in potash, and will apply his
common manure to the sandy parts of the farm, he will rarely need to
purchase manures containing potash.

CHAPTER XL.

RESTORING FERTILITY TO THE SOIL.

By Sir J. B. Lawes, Bart., LL.D., F.R.S., Rothamsted, Eng.

A relation of mine, who already possessed a very considerable estate,
consisting of light land, about twenty years ago purchased a large
property adjoining it at a very high price. These were days when farmers
were flourishing, and they no more anticipated what was in store for
them in the future, than the inhabitants of the earth in the days of
Noah.

Times have changed since then, and bad seasons, low prices of wheat, and
cattle-disease, have swept off the tenants from these