84 VEGETABLE FORCING 



proper amount of lime for greenhouse soils. One pound 

 of unslaked stone lime is considered sufficient for 20 

 square feet of space, and double that amount will do no 

 harm. It should be scattered evenly over the surface and 

 thoroughly mixed with the soil. See page 64 relating 

 to the functions of lime. 



Applying fertilizers. When commercial fertilizers are 

 employed they are usually applied after plowing or 

 spading and mixed with the soil by subsequent harrow- 

 ing or raking. Nitrate of soda is often used as a top- 

 dressing, applied either in dry or liquid form. Excessive 

 amounts of fertilizers may cause curling, wrinkling or 

 burning of the leaves. About l /\. ton to the acre of 

 mixed mineral forms of commercial fertilizers is probably 

 as much as can be used with safety on any of our green- 

 house crops. One ounce of nitrate of soda to each gallon 

 of water may be applied to lettuce and other crops with- 

 out danger of injury unless the soil already contains a 

 large amount of mineral fertilizers. For more specific 

 information, see the discussion of fertilizers in connection 

 with each class of vegetables. 



