120 FERTILITY AND FERTILIZER HINTS 



No. I containing 2 per cent, and No. 2 carries all of its nitrogen 

 in this form. The chemist cannot always tell the source of the 

 organic nitrogen. When the organic nitrogen is derived from 

 dried blood, azotin, cotton-seed meal, steamed horn and hoof 

 meal, and similar nitrogenous organic materials it is valuable but 

 when derived from leather preparations, dissolved wool and 

 shoddy wastes, etc., it is not so desirable. Therefore the pur- 

 chaser would perhaps select Brand No. i for its nitrogen con- 

 tent as it is to be supposed that the manufacturer using high 

 grade materials as nitrate of soda and sulphate of ammonia would 

 furnish organic nitrogen from high grade materials. 



A glance at the phosphoric acid constituents shows that both 

 run 10 per cent, available phosphoric acid but No. i contains 6 

 per cent, more phosphoric acid in the soluble form. As soluble 

 phosphoric acid distributes more readily in the soil than reverted 

 phosphoric acid and is more available as plant food, we would 

 naturally prefer Analysis No. i from the phosphoric acid stand- 

 point. Glancing at the potash we find that No. i carries 2 per 

 cent, as chloride and 7 per cent, as sulphate, while No. 2 shows 

 8 per cent, as chloride and i per cent, as sulphate. For crops 

 like tobacco, potatoes, sugar-beets, oranges, etc.. No. i would 

 be the most suitable, since these crops do better with sulphate of 

 potash than with muriate of potash. The potash in No. i was in 

 all probability derived mostly from sulphate of potash while that 

 in No. 2 came mostly from muriate of potash. 



Here is another statement that is used by some chemists in re- 

 porting analyses. 



Chemical Analysis, No. 3. 



rer cent. 



Nitrogen 3.00 



Soluble phosphoric acid 7.00 



Reverted phosphoric acid 3.00 



Insoluble phosphoric acid 2.00 



Available phosphoric acid 1 0.00 



Potash 9.00 



This Statement is not so valuable as Nos. i and 2 because the 

 forms of nitrogen and potash are not given. The nitrogen may 

 all be from nitrate of soda, or sulphate of ammonia, or organic 



