“Numerous experiments have been made in this country, with guano and superphosphate of lime; but the superphosphates used were commercial articles, containing more or less ammonia, and if they are of any benefit to those crops to which they are applied, it is a matter of uncertainty whether the beneficial effect of the application is due to the soluble phosphate of lime, or to the ammonia. On the other hand, guano contains both ammonia and phosphate; and we are equally at a loss to determine, whether the effect is attributable to the ammonia or phosphate, or both. In order, therefore, to determine satisfactorily, which of the several ingredients of plants is required in greatest proportion, for the maximum growth of any particular crop, we must apply these ingredients separately, or in such definite compounds, as will enable us to determine to what particular element or compounds the beneficial effect is to be ascribed. It was for this reason, that sulphate of ammonia, and a purely mineral superphosphate of lime, were used in the above experiments. No one would think of using sulphate of ammonia at its price, [sulphate of ammonia is now cheaper, while Peruvian guano is more costly and less rich in ammonia], as an ordinary manure, for the reason, that the same quantity of ammonia can be obtained in other substances, such as barnyard-manure, Peruvian guano, etc., at a much cheaper rate. But these manures contain all the elements of plants, and we can not know whether the effect produced by them is due to the ammonia, phosphates, or any other ingredients. For the purpose of experiment, therefore, we must use a manure that furnishes ammonia without any admixture of phosphates, potash, soda, lime, magnesia, etc., even though it cost much more than we could obtain the same amount of ammonia in other manures. I make these remarks in order to correct a very common opinion, that if experiments do not pay, they are useless. The ultimate object, indeed, is to ascertain the most profitable method of manuring; but the means of obtaining this information, can not in all cases be profitable.
“Similar experiments to those made on Indian corn, were made on soil of a similar character, on about an acre of Chinese sugar-cane. I do not propose to give the results in detail, at this time, and allude to them merely to mention one very important fact, the superphosphate of lime had a very marked effect. This manure was applied in the hill on one plot (the twentieth of an acre,) at the rate of 400 lbs. per acre, and the plants on this plot came up first, and outgrew all the others from the start, and ultimately attained the height of about ten feet; while on the plot receiving no manure, the plants were not five feet high. This is a result entirely different from what I should have expected. It has been supposed, from the fact that superphosphate of lime had no effect on wheat, that it would probably have little effect on corn, or on the sugar-cane, or other ceralia; and that, as ammonia is so beneficial for wheat, it would probably be beneficial for corn and sugar-cane. The above experiments indicate that such is the case, in regard to Indian corn, so far as the production of grain is concerned, though, as we have stated, it is not true in reference to the early growth of the plants. The superphosphate of lime on Indian corn, stimulated the growth of the plants, in a very decided manner at first, so much so, that we were led to suppose, for some time, that it would give the largest crop; but at harvest, it was found that it produced no more corn than plaster. These results seem to indicate, that superphosphate of lime stimulates the growth of stalks and leaves, and has little effect in increasing the production of seed. In raising Indian corn, for fodder or for soiling purposes, superphosphate of lime may be beneficial, as well as in growing the sorghum for sugar-making purposes, or for fodder—though, perhaps, not for seed.”
“In addition to the experiments given above, I also made the same season, on an adjoining field, another set of experiments on Indian corn, the results of which are given below.
“The land on which these experiments were made, is of a somewhat firmer texture than that on which the other set of experiments was made. It is situated about a mile from the barn-yard, and on this account, has seldom, if ever been manured. It has been cultivated for many years with ordinary farm crops. It was plowed early in the spring, and it was harrowed until quite mellow. The corn was planted May 30, 1857. Each experiment occupied one-tenth of an acre, consisting of 4 rows 3½ feet apart, and the same distance between the hills in the rows, with one row without manure between each experimental plot.
“The manure was applied in the hill, in the same manner as in the first set of experiments.
“The barnyard-manure was well-rotted, and consisted principally of cow-dung with a little horse-dung. Twenty two-horse wagon loads of this was applied per acre, and each load would probably weigh about one ton. It was put in the hill and covered with soil, and the seed then planted on the top.
“The following table gives the results of the experiments:
TABLE SHOWING THE RESULTS OF EXPERIMENTS ON INDIAN CORN, MADE NEAR ROCHESTER, N.Y., IN THE YEAR 1857.
| SdC Bushels of ears of sound corn per acre. SfC Bushels of ears of soft corn per acre. TC Total No. of bushels of ears of corn per acre. ISdC Increase per acre of ears sound corn. ISfC Increase per acre of ears of soft corn. TIC Total increase per acre of ears of corn. |