but instead of bulk the proper elements as fertilizers in a concentrated 

 form are more valuable as plant food than many manures and many so 

 called " commercial fertilizers " a hundred times as bulky. Fertilizers 

 in some form can be made to last like barnyard manure, and feed several 

 successive crops with a single application. For instance, in ashes and 

 bone we have all the elements for a complete manure, when all that is 

 required is to apply an extra quantity of ashes and a portion of the bone 

 in a coarse state. Ashes are always enduring in their effect, and the 

 coarser bone will be years in decaying and setting free nitrogen and phos- 

 phoric acid. To continually apply but a single one of the three elements 

 which enter into the complete manure, and especially if that one should 

 be nitrogen, and for a series of years be in marked excess of the other 

 two, would, in the end, sooner .or later, prove that the conclusions often 

 advanced are correct, however faulty they might have been in their rea- 

 soning. The fact that the one of the three elements, nitrogen, potash, 

 or phosphoric acid, of which the soil has the least, and which has been 

 repeatedly proven, will always be the measure of the crop. A hundred 

 pounds of potash, applied would not give a larger yield than five pounds 

 (and so of the other two elements), if there is not a proportionate in- 

 crease of the other elements. 



" The right way is to make the most and best manure that is practi- 

 cable upon the farm, and piece out with such commercial fertilizers as 

 experiments and experience prove profitable. At the same time there 

 are many cases, especially near cities, where everything depends upon 

 getting the largest and best (and earliest) yield, where the more exclu- 

 sive use of chemical fertilizers is advisable." * 



Artificial fertilizers are, of course, much more cheaply transported, 

 and unlike barn manure they do not carry with them seeds of weeds 

 into the soil, and as they contain the fertilizing elements in so condensed 

 a form the whole handling of them becomes much cheaper, where they 

 can be obtained from reliable sources. 



" Fertilizers rich in ammonia, Peruvian guano, sulphate of ammonia, 

 etc., should be applied a little at a time and often." f 



Clayey soils do not as a rule need so much potash or nitrogen as 

 phosphoric acid. Nitrogen tends to promote leaf growth. Fertilizers 

 applied to poor land produce more effect than when applied to rich land. 

 If the bone in the soil does not all decompose the first year, the nitrogen 

 contained in it goes over with it and is not lost. If but one of the ele- 

 ments is to be used it should by all means be bone, and the finer the 

 bone and the finer and drier the fertilizer the more valuable it is. When 

 the animal matter in bone decays the phosphoric acid in the bone is in 



a reverted condition. 



BONES. 



The bones of land animals are composed of the following elements: 



4Q ft 



Gelatine, fat, and water - .- 



Phosphate of lime, with a little magnesia 4 .u 



Carbonate of lime 2Q 



Potash and soda """ '_ 



100.0 



*Savs Professor Atwater, 

 Atv 

 ;gro 

 was 

 2H 



. . 



^0^ The RrowS%hould noTfTrget that in using potash or phosphoric acid in any 

 fofm'n"eve? washes in the soil to any extent, and one application will last several years. 



