The Cornell Reading-Courses 



PUBLISHED BY THE 



NEW YORK STATE COLLlSGE OF AGRICULTURE AT CORNELL UNIVERSITY 



Entered as second-class matter at the post ofiQce at Ithaca, New York 



B. T. Galloway, Director A. R. Mann, General Editor 



COURSE FOR THE FARM, ROYAL GILKEY, Supervisor 



VOL. IV. No. 74 



OCTOBER 15, 1914 



THE SOIL SERIES 

 No. I revised 



INTRODUCTION TO THE PRINCIPLES OF SOIL FERTILITY 



Elmer 0. Pippin 

 This lesson is the first of a series deaUng with the maintenance 

 of a proper physical condition and 

 adequate productiveness of the soil. 

 It points out the primary means by 

 which soils are made productive, 

 and outlines and introduces the 

 discussion of the various factors by 

 which this is accomplished. 



MAINTENANCE OF FERTILITY OP 

 THE SOIL 



The most fundamental prob- 

 lem in agriculture is the main- 

 tenance and increase of the 

 productive capacity of the 

 soil. All important forms of 

 plant as well as of animal life 

 depend on the soil for the 

 ultimate supply of material 

 necessary to their growth. 

 The materials that come 

 from the soil are the most 

 likely to become the 

 limiting factors in crop 

 production. Therefore 

 the great problem 

 identified with agricul- 

 ture, and ultimately 



vv, 11 i^v, ■ A -^^ ^^^- I- — ^^^^ diagram represents the essential factors in a 

 witn au otner maustry, j^^^^^ ^^-^ ^^ ^^^ ^^^^^ ^^ .^,;„-^;j ^^^^y should be adjusted, he- 

 is the maintenance of ginning at the base. 'It also calls attention to the primary 

 adequate productive- ^'''''''''' ^^ ""^''^ '^'' essential factors are controlled 

 jiess of the soil, commonly considered tmder the head of soil fertility, 



