"That is certainly correct for clover so far as this kind of soil is
concerned," said Mr. West. "Clover never amounts to much on this
kind of land, except where heavily fertilized. When fertilized it
usually grows well. Does the farm fertilizer neutralize the acid?"

"Only to a small extent. It is true that farm manures contain very
appreciable amounts of lime and some other alkaline, or basic,
substances, but in addition to this, and perhaps of greater
importance, is the fact that such fertilizer has power to feed the
clover crop as well as other crops. In other words it furnishes the
essential materials of which these crops are made. In addition to
this the decaying organic matter has power to liberate some plant
food from the soil which would not otherwise be made available
although to that extent the farm manure serves as a soil stimulant,
this action tending not toward soil enrichment but toward the
further depletion of the store of fertility still remaining in the
soil."

"This seems a complicated problem," said Mr. West, "but may I now
show you some of our more productive land?"

"As soon as I collect a sample of this," replied Percy, and to Mr.
West's surprise he proceeded to bore about twenty holes in the space
of two or three acres. The borings were taken to a depth of about
seven inches, and after being thoroughly mixed together an average
sample of the lot was placed in a small bag bearing a number which
Percy recorded in his note book together with a description of the
land.