22 VEGETABLE GARDENING. 



Sulphate of Ammonia is a by-product from gas works and 

 contains about 20 per cent of nitrogen. It does not act as 

 quickly as nitrate of soda, but for late crops, to be applied 

 during warm weather, it is one of the best sources of nitrogen. 



Superphosphate is made by treating ground bone or nodu- 

 lar phosphate with sulphuric acid to render the phosphates 

 soluble. It is rich in phosphoric acid, and some kinds con- 

 tain a considerable quantity of nitrogen. They vary much in 

 quality. The better kinds are generally used at the rate of 

 about 400 pounds per acre. 



Wood Ashes is rich in potash and a valuable fertilizer in 

 many cases, provided it has not been leached: if it has been 

 leached, it is practically worthless as a fertilizer. Ashes from 

 hard wood is much more valuable than that from soft wood 

 on account of its containing much more potash. Ashes is 

 one of the best fertilizers for fruit trees and plants. About 

 twenty bushels of unleached hard wood ashes is generally 

 sufficient for one acre, but much more may be safely used. 



Kainite. — Potash is also applied to the land in the form 

 of German potash salts, a grade of which, known as Kainite, 

 is very commonly used as a fertilizer. These salts are more 

 or less mixed with common table salt and other impurities 

 and form a cheap and very useful supply of potash. They 

 are generally sold on a valuation based on the percentage of 

 actual potash they contain. Kainite contains 13 per cent of 

 potash, which is more than twice as much as there is in ordin- 

 ary unleached wood ashes. From 200 to 600 pounds of 

 kainite is generally applied per acre. 



Lime is found in abundance in most western soils, but burned 

 limestone, whether as fresh slacked or as quick lime, may often 

 be used to advantage in small quantities when large amounts of 

 stab lemanurehave been used upon the land for a number of years. 

 It should not be used alone, because it exhausts the soil. 



Land Plaster is a sulphate of lime. It is not a direct 

 fertilizer, and its method of action is not exactly known. It 

 may occasionally be used to advantage for leguminous crops, 

 .such as clover, beans, peas, etc., in applications of from 200 

 to 600 pounds per acre spread broadcast. 



There is little use for commercial fertilizers at present in 

 most of the western states and they should never be used until 



