He passed to the next plot, and was very enthusiastic over it. “What have you here?” —“Rape-cake and ammonia,” said I. —“It is a grand crop,” said he, and after examining it with great interest, he passed to the next, 6a. —“What have you here?” —“Ammonia,” said I; and at 6b he asked the same question, and I replied “ammonia.” At 7a, the same question and the same answer. Standing between 7b and 8a, he was of course struck with the difference in the crop; 8a was left this year without any manure, and though it had received a liberal supply of mineral manures the year before, and minerals and ammonia-salts, and rape-cake, the year previous, it only produced this year, 3½ bushels more than the plot continuously unmanured. The contrast between the wheat on this plot and the next one might well interest a practical farmer. There was over 15 bushels per acre more wheat on the one plot than on the other, and 1,581 lbs. more straw.
Passing to the next plot, he exclaimed “this is better, but not so good as some that we have passed.” —“It has had a heavy dressing of rape-cake,” said I, “equal to about 100 lbs. of ammonia per acre, and the next plot was manured this year in the same way. The only difference being that one had superphosphate and potash, soda, and magnesia, the year before, while the other had superphosphate alone.” It turned out, as you see from the table, that the potash, etc., only gave half a bushel more wheat per acre the year it was used, and this year, with 2,000 lbs. of rape-cake on each plot, there is only a bushel per acre in favor of the potash, soda, and magnesia.
The next plot, 9b, was also unmanured and was passed by my father without comment. “Ah,” said he, on coming to the two next plots, 10a and 10b, “this is better, what have you here?” —“Nothing but ammonia,” said I, “and I wish you would tell me which is the best of the two? Last year 10b had a heavy dressing of minerals and superphosphate with ammonia, and 10a the same quantity of ammonia alone, without superphosphate or other mineral manures. And this year both plots have had a dressing of 400 lbs. each of ammonia-salts. Now, which is the best—the plot that had superphosphate and minerals last year, or the one without?” —“Well,” said he, “I can’t see any difference. Both are good crops.”
You will see from the table, that the plot which had the superphosphate, potash, etc., the year before, gives a peck less wheat this year than the other plot which had none. Practically, the yield is the same. There is an increase of 13 bushels of wheat per acre—and this increase is clearly due to the ammonia-salts alone.
The next plot was also a splendid crop.
“What have you here?”
“Superphosphate and ammonia.”
This plot (11a), turned out 35 bushels per acre. The next plot, with phosphates and ammonia, was nearly as good. The next plot, with potash, phosphates, and ammonia, equally good, but no better than 11a. There was little or no benefit from the potash, except a little more straw. The next plot was good and I did not wait for the question, but simply said, “ammonia,” and the next “ammonia,” and the next “ammonia.”—Standing still and looking at the wheat, my father asked, “Joe, where can I get this ammonia?” He had previously been a little skeptical as to the value of chemistry, and had not a high opinion of “book farmers,” but that wheat-crop compelled him to admit “that perhaps, after all, there might be some good in it.” At any rate, he wanted to know where he could get ammonia. And, now, as then, every good farmer asks the same question: “Where can I get ammonia?” Before we attempt to answer the question, let us look at the next year’s experiments.—The following is the results of the experiments the seventh year, 1849-50.