CHAPTER XII 

 THE APPLICATION OF NITROGEN -CARRYING FERTILIZERS 



The general purpose of fertilizer application is to increase yields. 

 In the orchard this may result from larger tree growth, from increased 

 fruit bud formation, from better setting of the fruit, from the production 

 of fruit of larger size, or from a combination of two or more of these 

 rather distinct responses. 



The Influence of Nitrogenous Fertilizers on Vegetative Growth. — 

 An abundant supply of available nitrogen in the soil has long been 

 associated, by well informed gardeners, with strong, vigorous growth. 

 So well is this connection recognized that gardeners and florists generally 

 have become skilled in the art of using nitrogenous fertilizers for vege- 

 tables and ornamental plants. Fruit growers, however, though inclined 

 to recognize the general value of such fertilizers, have, for one reason or 

 another, not employed them to any considerable extent and it is not until 

 recent years that much experimental evidence has been available as to 

 their place in orchard practice. 



In Peaches. — Alderman^ reported the results of a series of fertilizer 

 experiments with peaches in West Virginia. The trees were growing in 

 a rather thin shale loam, a soil commonly used in that section for apples 

 and peaches, though it would generally be classed as rather unproductive. 

 Some of his data pertaining to shoot and leaf growth are assembled in 

 Table 67. They show that wherever nitrogen was used, shoot growth was 



Table 67. — Effect of Fertilization on Vegetative Growth of the Peach 

 {After Alderman-) 



Fertilizer treatment 



Average 

 shoot 



length, 

 4-year 



average 



(inches) 



Average 

 leaf area, 

 3-year 

 average 

 (square 

 inches) 



Number 



per tree, 

 3-year 

 average 



Leaf area „ 



Per cent 



per tree, 



3-year 



average 



(square 



feet) 



of fruit 

 buds, 

 4-year 



average 



Nitrogen and phosphoric acid. 



Nitrogen and potash 



Complete fertilizer 



Potash and phosphoric acid. . 



Check 



Complete fertilizer 



Complete with potash doubled 

 Complete with potash tripled. . 

 Lime. 



28 

 26 

 06 

 63 

 89 

 12 

 39 

 4.26 

 3.26 



25,424 

 24,808 

 23,208 

 8,768 

 10,596 

 29,536 

 32,368 

 22,648 

 14,172 



755.6 

 734.4 

 654.3 

 160.1 

 212.6 

 845.0 

 986.7 

 670.0 

 320.8 



80.6 

 75.5 

 74.0 

 58.0 

 57.9 

 76.6 

 75.2 

 76.2 

 64.4 



204 



