470 ANNUAL REPORT OF THE Off. Doc. 



LOW GKADE NITROGENOUS MATERIALS IN FERTILIZERS 



By DR. WILLIAM FREAR, Cheviist 



The average complete fei-tilizei* sold during the spring of lllll 

 iu Pennsylvania contained about L5 per cent, of nitrogen, 8,25 per 

 cent, of phosphoric acid, and 5.0 i)er cent, of potash, but the relative 

 cost to the purchaser of these materials, exclusive of mixing, bagging 

 and freight, was 36; 30; 25; that is, the nitrogen, b.y far the least 

 abundant constituent, was not (mly relatively, but absolutely the 

 most costly. 



The use of commercial fertilizers is steadily increasing and the 

 demand for fertilizer raw materials is growing at a similar rate, 

 notwithstanding tlie larger measure in which legumes are used in 

 our rotations and tlie better conservation of domestic manures, the 

 demand for organic nitrogenous raw materials for fertilizers is grow- 

 ing far more ra])id]y than the supply of first class materials, such 

 as bone, tankage and dried blood. The cost of nitrogen from these 

 sources is rising far more rapidly, as a conseiiuence, than that of rock 

 phosphoric acid and potash. 



The fact that nitrate and ammonia nitrogen now cost less than 

 organic nitrogen from prime materials, might suggest that fertilizer 

 makers would turn to nitrate of soda or sulphate of ammonia more 

 largely than in the past. Fertilizer analyses do not show any marked 

 tendency, however, toward such change. Manufacturers explain that 

 fertilizers whose nitrogen is exclusively supplied by nitrate of soda 

 or by sulphate of ammonia do not hold con(Jition well, and conse- 

 quenth' are unsatisfactory to the buyer because he cannot conven- 

 iently drill them; and that moreover, fertilizers that become available 

 gradually through the season are better for most crops than are such 

 ifertilizers as hold all their nitrogen in immediately available form. 

 There is a third reason he doesn't say much about, namely, that he 

 has found a way to use cheap organic materials to su])ply the nitro- 

 gen and that, at least in many cases, he is supplying an important 

 portion of the 1.5 per cent, we find present, by the use of hair, wool 

 waste, leather, garbage, tankage and peat. 



Decades ago, these cheap and abundant nitrogenous materials were 

 tried and found wanting, ^^'hile horn meal gave considerable crop 

 return, woolen rags some, and hair, leather, and peat a little, these 

 low grade materials, despite the large proportions of nitrogen some 

 of them contained, v.-ere found to have only very low fertilizer value; 

 consequently their use as fertilizer ingredients was condemned. 



In recent years, this condemnation has gone to the length of re- 

 quiring their use, when it occurs, to be declared. In the new fertilizer 

 Act of 190D for Pennsylvania, this requirement is made specific for 

 pulvei'ized leather, hair, ground hoof, horn, or wool waste, raw, 

 steamed, roasted, or in any form. 



