259 



the economy of l)nyiii<i' " coinplete '' or mixed /'s. '' iii('()in])le(e " or 

 immixed fertilizers : 



"Statistics secured by the station, and published in the annual 

 report for 1888, showed that the ayerage composition of mixed or 

 complete fertilizers analyzed durino- the year was 2.77 per cent nitro- 

 gen, 8.00 per cent available i)h()sphoric acid, 2.82 per cent insoluble 

 phosphoric acid, and 4.29 per cent potash, and that the average sel- 

 ling price was $84.83 per ton; in other words, the nitrogen cost on 

 an average 21 cents per pound, available phosphoric acid 10.2 cents, 

 insoluble i^hosphoric acid 3.8 cents, and potash 5.4 cents. The same 

 amount and kind of plant food could have been bought that year at 

 the factory, unmixed and for cash, at an average price of $27.42 per 

 ton. The average charge for mixing, freighting, and selling was, 

 therefore, $7.41 per ton." 



"■ Statistics in regard to the composition and cost of complete 

 manures in 1888 showed that the aAerage cost of the nitrogen con- 

 tained in them was just one-third of their total cost. In the use of 

 fertilizing materials, and especially of this most expensive element, 

 nitrogen, great care should be exercised; and the use of unmixed 

 materials, for studying the various soils and crops, is advised." 

 BULLETIN No. (iO, OCTORER 30. 1889. 



Analyses of ouound bones and miscellaneous samples of fer- 

 TiLizEi:s. E. B. Voorhees, M. A. (pp. 2-11). — Analyses and calcu- 

 lated valuations are given in tabular form of seventy-five samples of 

 gi'ound bone, and seventeen other samj^les of "incomplete" ferti- 

 lizing matt-rials. The samples received at the station in 1889 were all 

 of good cliaracter. and showed a decided improvement in mechanical 

 condition over those examined in previous years. Ground bone is 

 shown to be a cheap and valuable source of nitrogen and phosphoric 

 acid. The demand for fertilizers quick in action tends to decrease 

 the use of bones, and their special value in adding to soil fertility, 

 while giving at the same time a profitable increase in yield, is often 

 overlooked. Market garden produce and (piick-growing field crops, 

 as a rule, respond more jjrofitably to quick-acting manures, and re- 

 quire the continued addition of smaller quantities of the more soluble 

 and available elements of plant food. Fi'uit trees, i)ermanent pas- 

 tures, and meadows, on the other hand, while also responding to 

 these, are further benefited by the addition of considerable quantities 

 of materials which have a more lasting effect and furnish a gradual 

 and continued supply of plant food. Well-ground bone, though 

 insoluble in water, is readih^ decomposed by the action of the soil, 

 and furnishes nitrogen and phosphoric acid to the crop in amounts 

 proportionate to the fineness to which it is ground. 



To determine the value of bones, the amount of nitrogen and phos- 

 phoric acid and the degree of fineness are taken into consideration. 

 In the average per cent of fineness of the samples examined at the 



