Fo pi d f ? r ^ ie y are largely used in fertilizer mixtures, for, as 

 . — already mentioned, nitrogen is the most expensive 

 34 ingredient in a fertilizer, and it is a great temptation 

 to the less scrupulous fertilizer manufacturer to get 

 his nitrogen from the cheapest source, and in a mix- 

 ture it is difficult for a farmer to detect the various 

 substances of which that mixture is composed. 



In Nitrate of Soda, Sulphate of Ammonia and 

 Dried Blood, we have three nitrogenous fertilizers, 

 placed in the order of the availability of their nitrogen. 

 Dried Blood is the slowest acting form. . . . Nitrate 

 of Soda is exceedingly quick acting, and, therefore, 

 ought not to be applied long before the crop is ready 

 to assimilate its nitrogen. In its rate of action, Sul- 

 phate of Ammonia is intermediate between the two. 

 . . . The special virtue of Nitrate of Soda is due to 

 the fact that it provides a readily available supply of 

 nitrogen to the young plant at a time when nitrifica- 

 tion in the soil is only commencing. 



Top-Dressings. 



Top-Dressing, as commonly under- 

 E f a pL < ^ rowth stood, means simply the application of 



plant food after seeding, and after the 

 crop has made some growth. It has various objects, 

 but chief among them is the fact that fall sown crops 

 should make an early start in the spring in order to 

 establish an extensive root system (foraging both for 

 food and water), and to protect the soil by shading 

 before the hot, dry days come. The earlier growth of 

 crops is largely a matter of Nitrate plant food, but in 

 the spring the soil is usually wet and cold, both con- 

 ditions unfavorable for the action of organisms which 

 convert the stored plant food into Nitrates. 



A very late spring may prevent the natural and 



usual Nitration of this kind of plant 

 How Nitrate food though large quantities may have 



Saves Time, been applied in the form of organic 



Money, and the ammoniates and other crude manures, 

 Crop * so that the warm weather finds the 



