No. 4.] CHEMICAL AND FARM MANURES. 153 



After what has been said iu relation to the various forms 

 of nitrogen, several points may be concisely stated : — 



1. Nitrogen in nitrates* acts more quickly than in other 

 substances, and is therefore particularly recommended where 

 supplementary applications are desirable during the period 

 of growth. 



2. Nitrate nitrogen is particularly adapted to vegetable 

 growing, greenhouse work or for the spring top-dressing 

 of. grass or grains; but, owing to its tendency to leach, it 

 should rarely be applied in the autumn, and if at all only on 

 very exhausted land, and in a quantity only sufficient to 

 give the crops a start before winter. 



If applied early and in large quantities to grain before it 

 is well started, there is a tendency to excessive straw pro- 

 duction at the expense of the grain. 



3. Upon acid soil, where there may be some delay or 

 difficulty in the transformation of other forms of nitrogen 

 into nitric acid, nitrates are particularly applicable, and will 

 give most tavoralile results with spinach, lettuce, beets, 

 asparagus. Kohl rabi, cauliflower, cabbage, tomatoes and 

 many other garden crops. 



4. On very light soils, or where the crop grows for a 

 long period, nitrates wdll generally prove more efficacious 

 if applied in two or three successive portions than when 

 applied at once. 



5. Owing to the danger of its being destroyed by deni- 

 tritication and the loss of the nitrogen as gas, but little 

 nitrate of soda should be applied at a time, either in the 

 greenhouses or in fields, in case excessive amounts of only 

 partially rotted manure have been employed. 



6. Sulfate of ammonia is less liable to loss by leaching 

 than nitrate of soda, and it is not quite so rapid in its action. 



7. Upon grass and cereals where, and at times when, the 

 conditions are favorable for its being carried into the soil 

 and quickly changed into nitrates, sulfate of ammonia is apt 

 to prove nearly as effective as nitrates. 



* Nitrate of potash, though an excellent source of nitrogen, is seldom used in 

 agricultural operations, for the reason that nitrogen and potash can usually be 

 bought in other materials for less money. 



