“You do not think, then,” said the Doctor, “that nitrogen is such an important element in manure for corn, as it is in a manure for wheat.”
I have not said that. If we want a large crop of corn, we shall usually need a liberal supply of available nitrogen. But this is because a larger crop of corn means a much larger produce per acre, than a large crop of wheat. Forty bushels of wheat per acre is an unusually large crop with us; but 80 bushels of shelled corn can be grown in a favorable season, and on rich, well-cultivated land. As the Deacon has said, 30 bushels of corn per acre can be grown as easily as 15 bushels of wheat; and it is quite probable, in many cases, that a manure containing no nitrogen, might give us a crop of 35 or 40 bushels per acre. In other words, up to a certain point, manures containing mineral, or carbonaceous matter, might frequently, in ordinary agriculture, increase the yield of Indian corn; while on similar land, such manures would have little effect on wheat.
“That is so,” said the Deacon, “we all know that plaster frequently increases the growth of corn, while it seldom does much good on wheat.”
But, after you have got as large a crop as the land will produce, aided by plaster, ashes, and superphosphate, say 40 bushels of shelled corn per acre, then if you want to raise 70 bushels per acre, you must furnish the soil with manures containing sufficient available nitrogen.
Some years ago, I made some careful experiments with artificial manures on Indian corn.
“Oh, yes,” said the Deacon, “they were made on the south lot, in front of my house, and I recollect that the N.Y. State Ag. Society awarded you a prize of $75 for them.”
“And I recollect,” said I, “how you and some other neighbors laughed at me for spending so much time in measuring the land and applying the manures, and measuring the crop. But I wish I could have afforded to continue them. A single experiment, however carefully made, can not be depended on. However, I will give the results for what they are worth, with some remarks made at the time:
“The soil on which the experiments were made, is a light, sandy loam. It has been under cultivation for upwards of twenty years, and so far as I can ascertain has never been manured. It has been somewhat impoverished by the growth of cereal crops, and it was thought that for this reason, and on account of its light texture and active character, which would cause the manures to act immediately, it was well adapted for the purpose of showing the effect of different manurial substances on the corn-crop.
“The land was clover-sod, two years old, pastured the previous summer. It was plowed early in the spring, and harrowed until in excellent condition. The corn was planted May 23, in hills 3½ feet apart each way.