“You have just finished threshing,” said the Deacon, “and for my part, I would rather hear how your wheat turned out, than to listen to any of your chemical talk about nitrogen, phosphoric acid, and potash.”
“The wheat,” said I, “turned out full as well as I expected. Fourteen acres of it was after wheat, and eight acres of it after oats. Both these fields were seeded down with clover last year, but the clover failed, and there was nothing to be done but to risk them again with wheat. The remainder was after barley. In all, there was not quite 40 acres, and we had 954 bushels of Diehl wheat. This is not bad in the circumstances; but I shall not be content until I can average, taking one year with another, 35 to 40 bushels per acre. If the land had been rich enough, there would unquestionably have been 40 bushels per acre this year. That is to say, the season was quite capable of producing this amount; and I think the mechanical condition of the land was also equal to it; all that was needed was sufficient available plant-food in the soil.”
“I can see no reason,” said the Doctor, “why you may not average 40 bushels of wheat per acre in a good season.”
“The field of 14 acres,” said I, “where wheat followed wheat, yielded 23 bushels per acre. Last year it yielded 22 bushels per acre; and so we got in the two years 45 bushels per acre.”
This field has had no manure of any kind for years. In fact, since the land was cleared, 40 or 50 years ago, I presume that all the manure that has been applied would not, in the aggregate, be equal to more than a good crop of clover-hay. The available plant-food required to produce these two crops of wheat came from the soil itself, and from the rain, dews, and atmosphere. The land is now seeded down with clover, and with the aid of a bushel or two of plaster per acre, next spring, it is not improbable that, if mown twice for hay next year, it will yield in the two crops three tons of hay per acre.
Now, three tons of clover-hay contain about 33 lbs. of phosphoric acid, 90 lbs. of potash, and 150 lbs. of nitrogen.
The last crop of wheat, of 22 bushels per acre, and say 1,500 lbs. of straw, would contain:
| In the grain. | In the straw. | In total crop. | |
|---|---|---|---|
| Phosphoric acid | 11½ lbs. | 3¾ lbs. | 15¼ lbs. |
| Potash | 6¾ ” | 9¾ ” | 16½ ” |
| Nitrogen | 23 ” | 9½ ” | 32½ ” |
It seems very unkind in the wheat-plants not to give me more than 22 bushels per acre, when the clover-plants coming after will find phosphoric acid enough for 40 bushels of wheat, and potash and nitrogen enough for nearly 100 bushels of wheat per acre. And these are the three important constituents of plant-food.
Why, then, did I get only 22 bushels of wheat per acre? I got 23 bushels on the same land the year previous, and it is not improbable that if I had sown the same land to wheat again this fall, I should get 12 or 15 bushels per acre again next year. But the clover will find plant-food enough for 40 bushels of wheat.