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FERTILIZERS FOR VEGETABLES 



if this laboratory is not well equipped, we shall not get those 

 compounds for which we grow many crops, such as sugar, 

 starch, proteins, and others. 



The effect of furnishing plants large amounts of available 

 nitrogen is to retard the maturing process, since the vegetative 

 activity is carried on in the stems and leaves at the expense 

 of growth in flower and fruit. This is highly desirable in 

 the case of many vegetable crops. 



We must also keep in mind another fact in regard to the 

 use of nitrogen in plant growth. The amount of nitrogen 

 furnished a plant regulates the general growth of the whole 

 plant and, therefore, the amount of plant-food constituents 

 that a plant can use. It is useless to furnish a crop large 

 amounts of available phosphoric acid or potash if we do not 

 at the same time supply some nitrogen ; because the amount 

 of phosphoric acid and potash a crop can use is more or less 

 largely controlled by the amount of nitrogen the crop gets. 



How does nitrogen affect the quality of vegetables? As- 

 suming, of course, that all conditions are favorable for plant 

 growth, the amount of nitrogen largely affects or determines 

 the following points in quality: Color, succulence or tender- 

 ness, size and keeping quality. Nitrogen is largely respon- 

 sible for, though not the direct cause of, greenness in leaves 

 and stems. Therefore, it is fair to say that, when we want 

 the right kind of bright green color in those crops which we 

 sell in the form of stems and leaves, we can get it only by a 

 generous use of nitrogen in plant-feeding. In respect to 

 succulence, tenderness and crispness in vegetables, especially 

 the stems and leaves, abundance of nitrogen must be used to 

 obtain products that possess these desired qualities in the 

 right degree. 



A question may properly be raised at this point: Is not 

 the use of nitrogen in excess often responsible for too rank, 

 coarse, and fibrous development of stems and leaves? The 

 use of nitrogen has been credited with those effects. I be- 

 lieve that the use of nitrogen in large amounts, when the 

 amounts of available phosphorus and potassium are rela- 

 tively too small, may be regarded as the cause of coarse tex- 

 ture and tough fibres, especially when the growth occurs at 



