In the following list are given the "trade values agreed upon by the Experiment Stations of Massachusetts, Rhode Island, Connecticut, New Jersey and Vermont, after a careful study of prices ruling in the larger markets of the southern New England and Middle States."
Trade values of fertilizing ingredients in raw materials and chemicals for 1904:
| Cents per lb. | |
| Nitrogen in Nitrates | 16 |
| Nitrogen in Ammonia Salts | 17½ |
| Organic Nitrogen in dry and fine ground fish, blood, and meat, and in mixed fertilizers | 17½ |
| Organic Nitrogen in fine ground bone and tankage | 17 |
| Organic Nitrogen in coarse bone and tankage | 12½ |
| Phosphoric Acid soluble in water | 4½ |
| Phosphoric Acid soluble in ammonium citrate | 4 |
| Phosphoric Acid in fine ground bone and tankage | 4 |
| Phosphoric Acid in coarse bone and tankage | 3 |
| Phosphoric Acid (insoluble in water and in ammonium citrate) in mixed fertilizer | 2 |
| Potash as high-grade sulphate and in mixtures free from muriate (chloride) | 5 |
| Potash as muriate | 4¼ |
For example, in calculating the commercial value of the plant food in a fertilizer we will take the formula mentioned on page 205, namely:
| Ammonia | 2 to 3 per cent. |
| Available Phosphoric Acid | 8 to 10 per cent. |
| Total Phosphoric Acid | 11 to 14 per cent. |
| Total Bone Phosphate | 23 to 25 per cent. |
| Actual Potash | 10 to 12 per cent. |
| Sulphate of Potash | 18 to 20 per cent. |
This fertilizer is evidently a mixture of bone meal and sulphate of potash and the plant food contained in it is as follows:
| Nitrogen | 1.65 per cent. |
| Available Phosphoric Acid | 8 per cent. |
| Insoluble Phosphoric Acid | 3 per cent. |
| Potash | 10 per cent. |
One hundred pounds of the mixture would contain:
| Pounds. | Value per 100 lbs. | |
| Nitrogen | 1.64 value at 17½¢ | .29 |
| Available Phosphoric Acid | 8 value at 4¢ | .32 |
| Insoluble Phosphoric Acid | 3 value at 2¢ | .06 |
| Potash | 10 value at 5¢ | .50 |
| —— | ||
| Total | $1.17 |
In one ton the whole value would be twenty times this or $23.40. Add to this $8, which is about the average charge for mixing, bagging, shipping, selling and profit, and we find that $32 is probably the lowest figure at which this fertilizer could be purchased on the markets, and very likely the price would be higher as we have taken the lowest guaranteed per cent. of plant food for our basis of calculation.