Agricultural Chemistry. 



reason it is not desirable to purchase it for making home mix- 

 tures. As it contains chlorides it should not be used as a fer- 

 tilizing material for tobacco, potatoes, or sugar beets. When 

 used it should be carefully applied to the soil so that it will not 

 come in contact with the seed, as it may seriously interfere with 

 germination. 



Tobacco stems. This is a by-product from tobacco factories. 

 It readily undergoes decomposition in the soil, its potash thus be- 



Potash mines at Stassfurth, Germany. Mining potash for fertilizers. 

 coming available. It contains from 2 to 2V 2 per cent of nitrogen, 

 from 6 to 8 per cent of potash and from 3 to 5 per cent of pho^- 

 phoric acid. In states where it can be secured at a compara- 

 tively low price, it can be used very profitably in making fer- 

 tilizer mixtures. 



Wood ashes. For many years they were the sole source of 

 potash for fertilizing purposes, but since the introduction of 

 the German potash salts, there is less of this material found on 

 the market. They are valuable when unleached, containing in 

 this condition from 2 to 8 per cent of potash. They are largely 



