CHAPTER III 

 SOILS 



THE soil considered agriculturally, is that part of 

 the earth's crust which is occupied by the roots of 

 plants and from which they absorb food and mois- 

 ture. 



RELATION OF SOIL TO PLANTS 



We have learned that plant roots penetrate the 

 soil to hold the plant in a firm and stable position, 

 to absorb moisture and with it plant food. We 

 learned also that for roots to do these things well, 

 the soil in which they grow must be mellow and 

 firm, and must contain moisture and plant food, 

 air must circulate in its pores and it must be warm. 



How can we bring about these conditions? To 

 answer this question intelligently it will be neces- 

 sary for us to study the soil to find out something 

 about its structure, its composition, its character- 

 istics ; also, how it was made and what forces or 

 agencies were active in making it. Are these forces 

 acting on the soil at the present time? Do they 

 have any influence over the conditions which are 

 favorable or unfavorable to plant growth? If so, 



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