CHAPTER II 

 THE TEXTURE AND STRUCTURE OF THE SOIL 



1. What Is Meant by Texture 



49. We have seen that the offices of the soil 

 are of two general kinds, it affords a physical 

 medium in which the plant can grow (41), and 

 it supplies materials that the plant uses in 

 the building of its tissues (42). It cannot be 

 said that one of these offices is more important 

 than the other, since both are essential; but 

 attention has been so long fixed upon the mere 

 content of soils that it is important to empha- 

 size the physical attributes. Crops cannot grow 

 on a rock, no matter how much plant-food it 

 may contain. The passing of rock into soil 

 is a matter of change in texture and structure 

 more than in plant-food. Texture refers to the 

 size of the particles ; structure to the arrange- 

 ment of the particles. 



50. The physical state of the soil may be 

 spoken of as its structure, much as we speak of 

 the structure of a house of brick or stone. The 

 common adjectives that are applied to the condi- 

 tion of agricultural soils are descriptions of its 



(37) 



241.189 



