CHAPTER H. 



NATURE AND ORIGIN OF THE SOIL.* 



All the plants grown upon the farm or in the garden grow in the 

 soil; even those that appear to be growing in streams and marshes 

 have their roots in the soil beneath the water. Sometimes we see 

 plants grow in water in the house or greenhouse, but most of 

 those found there are grown in pots filled with soil. The plants 

 found on the surface of rocks or on old rail fences are of a lovv% 

 simple order. We may then conclude that most of the plants 

 that we are most familiar with require the soil, and we therefore 

 shall study for a wdiile the soil, its nature, its origin, and its im- 

 provement. 



KINDS OF soil: — Sandy soil is made up principally of sand. If 

 we take a handful of dry sand we find that it consists of small 

 grains that are easily mixed together. If we moisten it, it will 

 cling together and can be moulded into various forms, but when 

 it dries the particles all fall apart into fine sand as before. Then 

 thei'e is clay of various colors, sometimes red, sometimes almost 

 white, and sometimes nearly blue. If we moisten it we can mould 

 it, but when it dries it keeps its shape and becomes hard. We 

 readily see the difference. When we walk over w^et sandy soil and 

 wet clayey soil, the former, when dry, readily rubs off our boots, 

 the latter sticks. Sand is used for making moulds in the foundry 

 and clay is usad for making models by the artist; the former read- 

 ily falls apart after being taken out of the boxes and can be used 

 again, and the latter when moulded and worked keeps its shape as 

 it dries. 



Make two sets of objects, such as balls, cubes, cups, vases, or simple 

 figure of small animals, one set from wet sand and one set from clay. 

 Place them in the sun or near the stove and observe the effect of drying. 



We see that sand as it dries does not stick together, and clay as 

 it dries does stick together and also sticks to other objects. We 

 now understand how it is that v^^et clay is sticky, it clings to the 

 plow and the harrow and to the feet of the horses and is hard or 

 heavy to work. Sandy soil is said to be light and clay soil to be 

 heavy, not because of their weight, but because the former is 

 easily worked and the latter is harder to work. If Ave watch closely 

 the drying out of the two sets of objects that we have moulded we 

 shall observe further that the sand dries more quickly than the 

 clay; the latter holds on to the water longer. Clay soils are unusual- 

 ly wet soils; they are more apt to have water in them than sandy 

 soils. 



*rrom Practical Agriculture, James. By kind permission of Messers. 

 D, Appl3ton &, Co.. New York. 



