FARMERS' INSTITUTES. 249 



ufacture is entirely "foreign to the legitimate business of the farm." If we 

 take into account the cost of ground bone (for the bone must be as fine as 

 sawdust), the cost of the acid, cost of transportation, the time required, the 

 danger of injury to the person or clothes by spilling the acid, I do not think it 

 will pay. If the farmer has a quantity of bones on hand, a better way would 

 be to mis them with unleached wood ashes, and keep the whole in a moist 

 condition for a few months, when the bones will be so soft they may be crushed 

 with a spade. 



Superphosphate of lime is valuable as a manure for two reasons: In the 

 first place, the phosphate will be at once assimilated by the plant. It gives an 

 immediate return for the money invested. There is something singular about 

 this fertilizer. Where it is applied to the soil it unites with the iron and lime 

 of the soil, and goes into a condition insoluble in water. But it is so finely 

 divided, the plant can absorb it readily. Persons have supposed that the solu- 

 ble phospate nourished the plant in its younger stages, and the insoluble por- 

 tion when the plant became more mature. But from the fact that it is all 

 equally insoluble in the soil, this cannot be the case. In the second place, 

 superphosphate is valuable because it sets free otlier elements in the soil for 

 the use of plants. For example, it was found in England some years ago, 

 that superphosphate was a very valuable manure for turnips. How to explain 

 it was the question, for the turnip is not a phosphate loving plant. Finally 

 it was discovered that phosphoric acid set free potash from its combinations, 

 and potash is just what the turnip wants. The indirect effect of manures in 

 setting plant food free in the soil, is often greater than its direct effect of feed- 

 ing the crop. Superphosphates are valuable for grain crops, because they 

 hasten the formation of the seed. Florists understand this fact well. If they 

 wish their plants to make a vigorous growth, they water their plants with a 

 dilute solution of ammonia (hartshorn). But if they wish their plants to 

 blossom, superphosphates are applied. 



What and how much of these concentrated fertilizers shall we apply to dif- 

 ferent crops, and in what way? This is a difficult question to answer, for soils 

 vary greatly in composition as well as the manures. We should study the 

 composition of different crops and see upon what substances the plant will 

 thrive the best and give the largest return. Wheat, barley, oats, rye, natural 

 grasses and beets are feeders on nitrogen especially, and this may be given 

 them in the form of guano or sulphate of ammonia, or nitrate of soda, or 

 nitrate of potash. Peas, beans, clover and potatoes are potash feeders espec- 

 ially, and will be benefited by potash salts, while maize, sorghum, and sugar 

 cane would be benefited by superphosphate of lime or bone dust, while tur- 

 nips are most benefited by superphosphate of lime. But the superphosphate 

 found in the market usually contains all these elements and could probably be 

 api)lied with good effect to any crop. 



The Michigan Carbon Works of Detroit, whose superphosphate represents 

 fairly the average of that class of manures, recommend the following amounts 

 for the various crops: "For corn or potatoes, apply one or two tablespoonfuls 

 to each hill, thoroughly mixing with the soil; then drop the seed — or corn can 

 be drilled in — 200 ll'S. to the acre. For wheat, 150 to 200 lbs. per acre, drilled 

 in with a fertilizer drill. If sown broadcast, 200 to 400 lbs. per acre. For 

 oats and barley, 100 lbs. per acre. For grass, 100 lbs., either late fall or 

 spring." But in the application of fertilizers no recipe can be strictly followed. 

 Each one must decide for himself by actual experiment what amount it is best 

 to use. 



