“The manures were applied in the hill immediately before the seed was planted.
“With superphosphate of lime, and with plaster (gypsum, or sulphate of lime), the seed was placed directly on top of the manure, as it is well known that these manures do not injure the germinating principle of even the smallest seeds.
“The ashes were dropped in the hill, and then covered with soil, and the seed planted on the top, so that it should not come in contact with the ashes.
“Guano and sulphate of ammonia were treated in the same way.
“On the plots where ashes and guano, or ashes and sulphate of ammonia were both used, the ashes were first put in the hill, and covered with soil, and the guano or sulphate of ammonia placed on the top, and also covered with soil before the seed was planted. The ashes and superphosphate of lime was also treated in the same way. It is well known that unleached ashes, mixed either with guano, sulphate of ammonia, or superphosphate, mutually decompose each other, setting free the ammonia of the guano and sulphate of ammonia, and converting the soluble phosphate of the superphosphate of lime into the insoluble form in which it existed before treatment with sulphuric acid. All the plots were planted on the same day, and the manures weighed and applied under my own immediate supervision. Everything was done that was deemed necessary to secure accuracy.
“The following table gives the results of the experiments:
TABLE SHOWING THE RESULTS OF EXPERIMENTS ON INDIAN CORN.
| 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. |
| Plot. | Descriptions of manures and quantities applied per acre. | SdC | SfC | TC | ISdC | ISfC | TIC |
|---|---|---|---|---|---|---|---|
| 1. | No manure | 60 | 7 | 67 | .. | .. | .. |
| 2. | 100 lbs. plaster (gypsum or sulphate of lime) | 70 | 8 | 78 | 10 | 1 | 11 |
| 3. | 400 lbs. unleached wood-ashes and 100 lbs. plaster (mixed) | 68 | 10 | 78 | 8 | 3 | 11 |
| 4. | 150 lbs. sulphate of ammonia | 90 | 15 | 105 | 30 | 8 | 38 |
| 5. | 300 lbs. superphosphate of lime | 70 | 8 | 78 | 10 | 1 | 11 |
| 6. | 150 lbs. sulphate of ammonia and 300 lbs. superphosphate of lime (mixed) | 85 | 5 | 90 | 25 | .. | 23 |
| 7. | 400 lbs. unleached wood-ashes, (uncertain) | 60 | 12 | 72 | .. | 5 | 5 |
| 8. | 150 lbs. sulphate of ammonia and 400 lbs. unleached wood-ashes (sown separately) | 87 | 10 | 97 | 27 | 3 | 30 |
| 9. | 300 lbs. superphosphate of lime, 150 lbs. sulph. ammonia, and 400 lbs. unleached wood-ashes | 100 | 8 | 108 | 40 | 1 | 41 |
| 10. | 400 lbs. unleached wood-ashes | 60 | 8 | 68 | .. | 1 | 1 |
| 11. | 100 lbs. plaster. 400 lbs. unleached wood-ashes, 300 lbs. superphosphate of lime, and 200 lbs. Peruvian guano | 95 | 10 | 105 | 35 | 3 | 38 |
| 12. | 75 lbs. sulphate of ammonia | 78 | 10 | 88 | 18 | 3 | 21 |
| 13. | 200 lbs. Peruvian guano | 88 | 13 | 101 | 28 | 6 | 34 |
| 14. | 400 lbs. unleached wood-ashes, 100 lbs. plaster, and 500 lbs. Peruvian guano | 111 | 14 | 125 | 51 | 7 | 58 |
“The superphosphate of lime was made on purpose for these experiments, and was a pure mineral manure of superior quality, made from calcined bones; it cost about 2½ cents per pound. The sulphate of ammonia was a good, commercial article, obtained from London, at a cost of about seven cents per pound. The ashes were made from beech and hard maple (Acer saccharinum) wood, and were sifted through a fine sieve before being weighed. The guano was the best Peruvian, costing about three cents per pound. It was crushed and sifted before using. In sowing the ashes on plot 7, an error occurred in their application, and for the purpose of checking the result, it was deemed advisable to repeat the experiment on plot 10.