The Purchase of Artificial Manures. 



difference in the value of insoluble phosphates. The insoluble 

 phosphate of bone meal, for instance, is less effective, and 

 for most purposes less valuable, than the insoluble phosphate 

 of basic slag, precipitated phosphate, or even dissolved bones. 

 Some of the insoluble phosphate of the last manure has 

 once been soluble, and has "reverted," and such phosphate 

 is not much less effective than soluble phosphate. But raw 

 bones as a manure have been longer known to British 

 farmers than other forms of phosphate, and for this reason, 

 their price has kept relatively high. 



The More Important Manures. 



Purely Nitrogenous Manures. 



The most important are nitrate of soda and sulphate of 

 ammonia, others in general use being rape dust, blood 

 meal, shoddy, etc. 



Other things being equal, nitrate of soda is specially 

 suitable : — 



(a) For use in spring and early summer, as in 



the manuring of hay, cereals, potatoes and 

 mangolds." 



(b) For use on heavy land. 



(c) For use as a top dressing 



(d) For use in a dry district. 



(e) For use where immediate effect is desired. 

 Speaking generally, sulphate of ammonia suits better : — 



[a) For use on crops that make their growth late in 



the season ; for example, turnips. 



[b) For use on light land. 



[c) For use on soil holding abundance of mild lime. 



[d) For use where it can be mixed with soil (in contrast 



to top-dressing). 



[e) For use in a wet district. 



It is, however, often difficult to say for which of these two 

 manures the conditions are most suitable, and then the 

 question should be decided either by the relative cost of. the 

 substances, or by using a certain amount of both. 



If one of the organic manures can be bought at a cheap* 



