HOW TO MAINTAIN FERTILITY 



Its potash is in the form of sulphates, but as it 

 contains large quantities of chlorides mixed with 

 it, it has the same general effect on plants as muri- 

 ate of potash. 



High-grade sulphate of potash contains forty- 

 eight to fifty-one per cent of potash, low grade 

 twenty-eight to thirty per cent, kainit twelve to 

 fourteen per cent, muriate of potash (eighty to 

 eighty-five per cent pure), fifty to fifty-three per 

 cent, and unleached wood ashes four to eight per 

 cent. Never use leached-wood ashes as a direct 

 fertiliser, as they usually contain but a small per- 

 centage of potash. 



When muriate of potash is used the chlorides 

 combine with the lime, forming chloride of lime, 

 which is very soluble and leaches away rapidly, a 

 distinct disadvantage, and it makes applications of 

 lime necessary. Further, the presence of large 

 quantities of chloride of lime in soil is apt to be 

 detrimental to plants. 



Greater effect is had from the use of these pot- 

 ash fertilisers on light, sandy soils, humus soils, or 

 those containing lime, than on heavy clay loams. 

 On the light soils, to get the full value of the 



potash applied, there should be in it considerable 



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