“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.

“I wish to have an analysis made of this sample,” remarked Percy, as they resumed their walk.

“But I thought you had analyzed this soil,” was the reply.

“Oh, I only tested for limestone and acidity,” explained Percy.  “I wish to have exact determinations made of the nitrogen and phosphorus, and perhaps of the potassium, magnesium, and calcium.  All of these are absolutely essential for the growth of every agricultural plant; and any one of them may be deficient in the soil, although” the last three are not so likely to be as the other two.”

“How long will it take to make this analysis?” was asked.

“About a week or ten days.  Perhaps I shall collect two or three other samples and send them all together to an analytical chemist.  It is the only way to secure positive knowledge in advance as to what these soils contain.  In other words, by this means we can take an absolute invoice of the stock of fertility in the soil, just as truly as the merchant can take an invoice of the stock of goods carried on his shelves.”

“So far as we are concerned, this would not be an invoice in advance,” remarked Mr. West, with a shade of sadness in his voice.  “If we knew the contents of the crops that have been sold from this farm during the two centuries past, we would have a fairly good invoice, I fear, of what the virgin soil contained; but can you compare the invoice of the soil with that of the merchant’s goods?”