NITROGEN GROUP OF FERTILIZERS i; 



must be regarded as a manure to be applied shortly before 

 it is needed. It is not so quick in its action as nitrate of 

 soda or nitrate of lime, but is a great deal quicker than the 

 organic nitrogen manures. Its stimulating effects on the 

 plant are seen in the large development of the leaf. It is 

 therefore especially valuable for the production of green 

 stuff, and is deservedly very popular among market gardeners 

 and all intensive cultivators. For the purpose of fruit 

 growing it is not such a suitable manure, since some fruits 

 do not develop well if the plant is too vigorous and rank 

 in its growth. Such prolific fruits as gooseberries must be 

 excepted from this general statement (see p. i66). 



Sulphate of ammonia, in a very crude form, occurs in 

 soot (see pp. 66 and 92). 



Ammonium Chloride. — Of the other compounds of 

 ammonia which have been used as fertilizers ammonium 

 chloride is probably the most important. Ammonium 

 chloride, sal ammoniac, or muriate of ammonia, has alwa^^s 

 been used in the Rothamsted experiments, doubtless because 

 at the date when these experiments were started it was b}^ 

 no means a foregone conclusion which particular ammonia 

 salt would prove most practicable. When ammonium 

 chloride is used as a manure many of the soil reactions 

 closely resemble those of the sulphate. The ammonia is 

 fixed in the soil, the chlorine carries awa^^ calcium (lime), 

 so that the ultimate result in the soil is the same. The 

 actions of sulphates and chlorides on plant life are nearly 

 but not quite identical, though these points can better be 

 discussed under the heads of the crops concerned (see 

 Part III.). At the present time there does not seem any 

 likelihood that ammonium chloride will be a practicable 

 fertilizer. 



Ammonium Nitrate. — Ammonium nitrate is a ver>' 

 deliquescent substance, and is for that reason not very 

 suitable as a fertilizer. Its very high percentage of nitrogen, 

 however, might make it valuable where transport facilities 

 were very poor. Though, at present this does not seem 

 a very practicable manure, it would certainly have the 

 D. . 2 



