Food for phosphate. This illustration is interesting as showing the 

 • P^^°^^ really heavy consumption of plant food by ordinary farm 

 i°6 crops. While the yield in this case is a large one, it is 

 precisely such yields all farmers are striving for. It is 

 probably true that an acre application of 800 pounds of 

 Nitrate of Soda would not give a profitable return with this 

 crop; but such crops actually make use of soil Nitrogen and 

 the roughage of the farm, and to do this most effectively, 

 top-dressings of Nitrate are advised to "start the crop off" 

 in the spring. 



In actual farming operations, the greater part of the 

 timothy crop will be returned to the soil in the form of 

 • farmyard manure, much of which will be applied in the fall. 

 A considerable portion of the ammoniate (Nitrogen) con- 

 tained in this manure will be converted into Nitrate during 

 the fall and winter, and such of this as the plants fail to 

 take up is dissipated by the spring rains and other causes. 

 Consequently, there is a lack of Nitrate Ammoniate in the 

 early spring, when the plants most need it, and this shortage 

 continues until the soil warms and becomes less charged 

 with water, when the organisms of the soil are enabled to 

 convert the vegetable substance containing ammonia into 

 the form suitable for the uses of the plants. Until this 

 action, the plants really starve for Nitrate; a situation 

 instantly relieved by top-dressings of Nitrate of Soda. 



r» i. -ni A u The following table shows the plant food 

 Part Played by » , r- , 



N't t PI t necessary to accompany each 100 pounds 



^ . . of ammonia (Nitrogen) assimilated by 



crops figured on a fair yield per acre: 



P Ammonia(Nitrogen). Potash. Soda. Phos. Acid. 



'^°P' Pounds. Pounds. Pounds. Pounds. 



Barley 100 74 — 25 



Buckwheat 100 59 — 21 



Corn 100 55 — 48 



Oats 100 93 — 33 



Wheat 100 43 9 34 



Onions '100 83 — 42 



Potatoes 100 132 2 38 



Rye 100 72 — 42 



Timothy 100 69 7 26 



The figures of the table are based on the complete crop, 

 including stalks, straw, vines, etc. The table shows roughly 



