“What is the use of talking about manure for oats,” said the Deacon, “if land is not rich enough to produce oats without manure, it certainly will not pay to manure them. We can use our manure on some crop that will pay better.”
“That is precisely what we want to know,” said I. “Very likely you are right, but have you any evidence?”
“Evidence of what?”
“Have you any facts that show, for instance, that it will pay better to use manure for wheat or barley than for oats?”
“Can’t say that I have, but I think manure will pay better on wheat than on oats.”
Mr. Lawes is making a series of experiments on oats. Let us take a hasty glance at the results of the first two seasons:
Experiments on Oats at Rothamsted.
| MANURES PER ACRE. | Grain, in bushels. | Straw, cwts. | Weight per bushel, lbs. | |||
|---|---|---|---|---|---|---|
| 1869 | 1870 | 1869 | 1870 | 1869 | 1870 | |
1.—No manure | 36⅝ | 16⅜ | 19¼ | 9⅛ | 36¾ | 35 |
2.—Mixed Alkalies and Superphosphate of Lime | 45 | 19⅛ | 24½ | 9⅝ | 38½ | 35⅛ |
3.—400 lbs. Ammonia-salts | 56⅛ | 37½ | 36⅞ | 17¼ | 37½ | 34¼ |
4.—Mixed Alkalies and Superphosphate, and 400 lbs.Ammonia-salts | 75¼ | 50⅝ | 54 | 28⅝ | 39¼ | 36 |
5.—550 lbs. Nitrate of Soda | 62¼ | 36½ | 42¾ | 23 | 38½ | 35¼ |
6.—Mixed Alkalies, Superphosphate, and 550 lbs. Nitrate ofSoda | 69⅜ | 50 | 49⅞ | 28¾ | 38½ | 35¾ |
It seems clear that, for oats, as for barley and wheat, what we most need in manure, is available nitrogen.
The first year, the no-manure plot produced 36⅝ bushels of oats per acre, weighing 36¾ lbs. per bushel, and plot 3, with ammonia-salts alone, 56⅛ bushels, and with nitrate of soda alone, on plot 5, 62¼ bushels per acre, both weighing 38½ lbs. per bushel. In other words, 82 lbs. of available nitrogen in the salts of ammonia gave an increase of about 20 bushels per acre, and the same quantity of nitrogen in nitrate of soda an increase of 26 bushels per acre.