386 SOILS 



of potash will be likely to aggravate the trouble. 

 If it is necessary to apply potash every year, alter- 

 nate the muriate with the sulphate, or with wood 

 ashes, and give the land an occasional dressing of 

 lime. Never mix muriate of potash with sulphate 

 of ammonia; the latter will lose part of its nitrogen. 

 The muriate is especially valuable for the lighter 

 soils, because it attracts moisture. 



Sulphate of Potash is bought in two forms, 

 "high grade and "low grade.' The former con- 

 tains 51 to 53 per cent, actual potash, which in 

 this form costs four and one-half cents a pound at 

 the current price of $45 a ton. High-grade sul- 

 phate of potash can be used safely for all crops. 

 Unlike the muriate it does not increase the loss of 

 lime from the soil ; although the potash in it costs a 

 trifle more than that in the muriate, the sulphate 

 is generally preferable for this reason. It is 

 especially preferable for tobacco, sugar beets, onions 

 and potatoes. Low grade sulphate of potash con- 

 tains about 26 per cent, of potash combined with 

 magnesia, which has a beneficial effect on some 

 soils. But the potash in it costs more than in 

 other forms, so that it is not used much in this 

 country. 



Many other materials are occasionally used as 

 fertilisers, such as tobacco stems and stalks, wool 

 and hair waste, seaweed, crude fish scrap, etc. 

 The amounts of food in the most common of these 

 are given in the Appendix. 



MIXING THE RAW MATERIALS 



If but one plant food is to be applied, the 

 material is put upon the land as it comes from the 

 dealers; if two or three are to be applied, the 



