68 FERTILITY AND FERTILIZER HINTS 



When excessive nitrogen is applied to potatoes it produces a 

 vigorous growth of vines but very few tubers are formed. Should 

 an excess of nitrogen be suppHed the small grain crops it would 

 cause them to lodge and produce grain of inferior quality and 

 the excess of the weight of the crop to the weight of the grain 

 would be high. Excessive nitrogen retards the formation of 

 fruit. It produces growth of wood and leaves when the fruit 

 should be forming. 



When nitrogen is lacking in the soil the plants do not grow 

 so high as when the supply is sufficient. With crops grown on 

 such soils the proportion of grain or seed to the weight of the 

 crop is high. No matter how much phosphoric acid and potash 

 there may be in the soil the crops can only use quantities in 

 proportion to the growth of the plants, and the growth of plants 

 will be in proportion to the nitrogen supply. 



Generally speaking an application of a nitrogenous fertilizer 

 will produce increased yields without the application of potash 

 and with an occasional supply of phosphoric acid. The nitrogen 

 produces a better leaf development, a better growth, the color of 

 crops become a darker green, and the crop matures later. Often 

 the supplying of nitrogen alone will increase yields to such an 

 extent that farmers may overate the value of this constituent. 

 On soils that are deficient in organic matter, that have been 

 continually cropped, the need of nitrogen is generally greater than 

 phosphoric acid and potash.* 



Market gardeners often take advantage of the power of ni- 

 trogen in the growing of lettuce and similar vegetables. Vege- 

 tables grown on soils more than amply supplied with nitrogen pro- 

 duce more delicate and tender vegetables, especially lettuce and 

 cabbage, but they do not stand shipping so well ; although better 

 for immediate consumption than vegetables grown on average 

 soils they wilt and spoil quickly and are not popular with the 

 commission houses. The cell walls and tissues are not so strong 

 with crops grown on excessive nitrogen as when not. 



Excessive Nitrogen Invites Diseases. — Crops grown on soils that 

 have excessive nitrogen are more susceptible to plant diseases 

 than on average soils. This may be noticed to a limited extent 



