382 The Land and Its Treatmeni 



proportions that experience has found to be useful. This 

 advice is particularly good when the person does not wish 

 to experiment or to give the. subject careful study. It is 

 less useful, perhaps, when one' does pot wish to enrich the 

 Jand as much as to give a stimulus to the young plant. 



It is generally considered that nitrogen promotes rapid 

 vegetative growth. It therefore may be used most freely 

 on plants desired for their foliage parts. If it promotes 

 growth, it also delays maturity. Therefore it should be 

 used sparingly, or only early in the season, on fruit-bear- 

 ing plants that tend to mature too late, as tomatoes and 

 eggplants. Experiments at Cornell years ago showed, that 

 a little nitrate of soda is better than much for tomatoes; 

 also, that a given quantity applied all at once early in the 

 season is better than the same quantity applied at inter- 

 vals, for in the latter case it promoted growth too late and 

 the fruits did not ripen (page 257). 



For the person who has studied the subject and his soil, 

 it is preferable to buy the elements in the form of high- 

 grade chemicals and to apply each by itself. He can then 

 apply little or much of any element to this place or to 

 that, as he thinks best. Good commercial sources of nitro- 

 gen are nitrate of soda, sulfate of ammonia and dried 

 blood; of potash, muriate of potash and unleached wood 

 ashes; of phosphoric acid, bone meal and acid phosphate 

 made from the rock phosphates of Tennessee, South Caro- 

 lina and Florida. Of nitrate of soda, 150 to 300 pounds 

 to the acre is a good application; of muriate of potash, 

 300 to 400 pounds; of treated rock, 200 to 400 pounds. 



The grower should conceive of a basic formula, and 

 then add or subtract to meet special needs. Voorhees 



