707 



The superphosphate, \vhen applied, being soluble in water, is 

 dissolved by rain and the moisture in the soil, and thoroughly per- 

 meates the soil, where the lime, iron, and alumina salts decompose 

 it, rendering it insoluble and depositing or fixing it in the soil in 

 such a line impalpable state that the plants can easily assimilate it 

 and have no difficulty in obtaining a good supply. By being in 

 this very line state equal dissemination through the soil is secured, 

 and the micro-organisms can obtain an unlimited supply of food for 

 their growth and activity in order to supply the plants ; whereas if 

 the manure had been placed in the soil in an insoluble state, even 

 if in a line powder, its uneven distribution through the soil would 

 limit the action and numbers of the active micro-organisms. By 

 reason of the great activity of this manure a quick and healthy 

 gro\vth is secured to the young plant, which is consequently better 

 able to cope with any attack from the pests that plants are liable to. 



Although superphosphate is one of the most valuable manures, 

 it is not in itself a complete manure. It is simply a supplier of 

 phosphoric acid and lime. It has to be used in conjunction with 

 either a potash or nitrogenous manure, or both, according to the 

 requirements of the crop. A great many manufacturers make super- 

 phosphates with either potash or nitrogen, or both, in them. These 

 superphosphates are generally sold under special names, such as tur- 

 nip manure, potato manure, &c., &c. As a rule these special manures 

 are not worth the high prices asked for them. They are very often 

 made up of some nitrogenous substance that is of very little value 

 in the soil as a manure, such as ground, steamed or vitrolised 

 leather, ground spent tan bark, shoddy, etc. The farmer who 

 supplies himself with these, generally from reading some glow r ing 

 advertisement or handbill, will have more of sorrow and vexation 

 of spirit to trouble him at harvest time than the burden of his crops. 

 The chemist is not able to discriminate, by mere analysis, between 

 the almost valueless nitrogen in leather and the highly valuable 

 nitrogen in bones when mixed with superphosphates. 



Although there are a great many special manures made, for 

 which a high price is charged, this has no relation to their value. 

 There are also a good many firms w r ho manufacture special 

 manures that contain all they say, and which are made of the best 

 materials. Those who buy them generally get full satisfaction, as 

 far as this class of manures can give satisfaction. Even if they 

 should be genuine, why buy them ? They are made for whoever 

 will buy them, the same to all round. Surely the requirements of 

 every soil are not the same. The farmer should know the 

 requirements of his soil for any given crop better than the manu- 

 facturer. This unintelligent manner of buying manure has had much 

 to do with the failure in the use of superphosphates in the hands 

 of some farmers. It will prove more satisfactory and cheaper for 

 the farmer to bay superphosphates, potash salts, and nitrogenous 

 manures separately, and mix them on the farm according to the 



