Manures and Fertilizers 



dition for a long period by the alternate application of nitrogenous manures 

 and super-phosphate. The principal sources of nitrogen, aside from natural 

 manures, such as horse, cow and sheep manures, which are frequently avail- 

 able to florists contiguous to large cities where numbers of domestic animals 

 are stabled, are as follows : 



First. Growing and ploughing under nitrogenous gathering crops, such as the 

 various clovers, cow peas and soy beans. 



Second. Nitrate of soda, which contains from 15 to 16^/^ per cent, of pure nitrogen 

 and may be purchased from dealers in fertilizing materials at prices ranging from $45.00 

 to $55.00 per ton. 



Third. Sulphate of ammonia, which contains 20 to 21 per cent, of nitrogen and 

 costs from $65.00 to $75.00 per ton. This is the richest of all of the ammonia compounds, 

 and when used with ground dried blood is particularly efficacious where a manure espe- 

 cially rich in nitrogen is desired. 



Fourth. One of the best of the chemical nitrogen compounds is nitrate of potash, 

 which contains 20 per cent, of nitrogen and 40 (o 42 per cent, of potash, and costs from 

 $4.65 to $6.00 per one hundred pounds. 



Fifth. Ground dried blood, containing 12 to 17 per cent, of nitrogen and from 

 a trace to 4 per cent, of phosphoric acid, costing $37.00 to $50.00 per ton, is also espe- 

 cially valuable for florists' use. 



Sixth. Peruvian guano, costing $45.00 to $55.00 per ton, is very rich in nitrogen 

 and is valuable for use in making liquid manures. 



Seventh. Ground sheep manure, also rich in available nitrogen, and costing from 

 $12.00 to $16.00 per ton, is particularly valuable for use as a liquid fertilizer, as well 

 as for top dressing growing plants upon benches, or sowing in the drills where young 

 plants are planted in the field. 



Eighth. Tankage, which contains from 4% to 10 per cent, of nitrogen and 10 to 45 

 per cent, of bone phosphate, costing from $25.00 to $35.00 per ton, is also an excellent 

 fertilizing material. 



Phosphoric Acid 



The next most essential element for plant growth is phosphoric acid, 

 which is contained in large quantities in most soils, but which may generally 

 be applied to advantage in connection with potash and nitrogen. One of the 

 principal sources from which phosphoric acid is derived is raw ground bone, 

 containing 20 to 22 per cent, of available phosphoric acid and about 4 per 

 cent, of nitrogen. Steamed or boiled bone, which contains more phosphoric 

 acid and less nitrogen than raw bone, is also more variable in composition, 

 depending upon the degree of steaming to which it has been subjected. The 

 refuse bone from glue factories, where the chief object is to extract the nitro- 

 genous matter from the bone, contains from 28 to 30 per cent, of phosphoric 

 acid and but a trace of nitrogen. 



Where bone is steamed at a high pressure, a favorable effect upon the 



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