PROFITABLE FARMING 7 



the crop more susceptible to fungoid attacks and 

 diseases of all kinds, as, for example, the disease 

 of potatoes and rust in grain. It also favours 

 the growth of straw, quite out of proportion to 

 that of grain, so that lodging is induced. 



Nitrogen is contained in nitrate of soda, sul- 

 phate of ammonia, and in the new forms derived 

 from the air, by electrical processes ; these are 

 readily soluble in water. It is also contained, in 

 organic form, in dried blood, meat meal, guanos, 

 bones, rape, and other seed meals. 



In nitrate of soda, the nitrogen being very 

 soluble and quickly available, it acts almost at 

 once, but as it is very soluble in 

 water and held very loosely by the 8 ^ te 

 soil, especially light sandy ones, there 

 is apt to be a considerable loss in wet seasons by 

 drainage. It is advisable never to use it until 

 the plants have their roots developed, so that 

 they can assimilate it without delay. As a top 

 dressing in the spring it is of great value. 



Sulphate of ammonia is not so rapid in its 

 action as nitrate of soda, as it has partly to 

 undergo a change in the soil, which 

 is known as nitrification, before it can 

 be entirely assimilated by the roots, 

 to which end the presence of carbonate of lime in 

 the soil is absolutely necessary. Pending this 

 change, which is a gradual one, sulphate of 

 ammonia has the advantage of not being readily 

 washed out of the soil and lost in the drainage 

 water. 



The continued use of either of these manures 



