Potassic Manures 



it will be necessary to give a preliminary dressing 

 of the latter to prevent the potash being lost. More- 

 over, it will be necessary to renew the application, 

 because the fixation of the potash will cause a loss of 

 lime in the drains. In practice this restitution of 

 lime can often be effected by the employment of slag 

 as a phosphatic manure. 



Generally speaking, if the potassic salts are dry 

 the colour will matter little, but the content of potash 

 must be guaranteed, and the purchaser should also 

 ask for the content of accessory salts, and demand 

 the exact name of the manure he is buying. The 

 believers in magnesia as a manure, for example, will 

 be contented to use kainite, which will give them 

 magnesia in very large quantities. Kainite itself 

 is not much adulterated, but it is sometimes used to 

 adulterate chlorure and sulphate of potash. It is 

 also occasionally used to adulterate nitrate of soda, 

 and this fact is the more serious, because, nitrate 

 generally being given at the commencement of 

 vegetation, the kainite may then injure or destroy 

 the crop. 



Kainite. 



Kainite, the best known potassic manure, is 

 a crude salt, mined from deep-seated beds at Stass- 

 furt, in Germany. It is of a dirty colour generally, 

 sometimes pinkish, but the colour does not matter ; 

 the kainite is equally good in either case. 



Crude kainite consists of various more or less 

 pure salts, mixed after coming from the mine to 

 contain a proportion of from 12 to 13 per cent, 

 potash. It must not contain less than 12 per cent., 



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