CHAPTER III 



THE TEXTURE OF THE SOIL 



Meaning of Texture and Conditions by which it is affected Pore 

 Space and Density of Soils Capacity of the Soil for Water 

 Surface Tension and Capillarity Percolation and Drainage 

 Hygroscopic Moisture. 



IN the preceding chapter, the nature of the particles 

 composing the soil has been discussed ; it now remains 

 to consider the manner in which they may be arranged, 

 and the structure that results from the interaction 

 of the soil particles, the water, and such salts as may 

 be dissolved in the water. On these factors depend 

 what the farmer knows as the "texture" of the soil, 

 the degree of resistance it affords to the passage of a 

 plough, etc., the ease or otherwise with which that prime 

 object of cultivation, the preparation of a seed bed, can 

 be attained. 



It is clear that as a soil consists of particles there 

 must be between them a certain amount of space 

 which is occupied by air or water ; this is known as the 

 " pore space," and on its amount will largely depend the 

 density of the soil. Taking the simplest theoretical 

 case, a soil made up of equal spheres in contact with one 

 another, it will be found that the pore space is de- 

 pendent upon the method of packing, but not upon the 

 size of the spheres. If the system of packing shown in 

 A and B, Fig. 3, is adopted, the pore space reaches its 



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