MISCKLLANKOUS FKRTILl/'.KR MATKRIALS 103 



the crop. Most of our soils are well furnished with these con- 

 stituents. Coninion salt is cheaper than sulphates of soda or 

 magnesia and when needed will serve the same purpose, namely, 

 to render potash available.'^ 



Carbonate of magnesia is sometimes found on the market but 

 carbonate of lime performs the same functions except that mag- 

 nesia is not supplied, so that we need not consider this material 

 in our fertilizer problems. 



Ammonium chloride and ammonium carbonate are not good 

 fertilizers because they injure plants. Ammonium chloride is 

 sometimes called sal-ammoniac and in the pure state it is rather 

 expensive. 



Manganese Salts. — Manganese is found in small amounts in 

 plants and it is said to stimulate their growth. This element 

 is not necessary to apply as soils contain enough of it to satisfy 

 the wants of the plant. 



