50 



PRODUCTIVE FARMING 



easily. The animals also drag into their homes nesting mate- 

 rials and other vegetable matter. When this decays it aids 

 in forming fertile soil. 



How Soils are Moved. The same forces that form soil 

 also carry it away. Soil is almost constantly moving from 

 high lands to low lands. It is deepest in the valley, and 

 thinnest at the top of the hill. Great furrows are formed in 



the hillsides after heavy rains. 

 The swollen and muddy 

 streams carry the soil to lower 

 parts of the land. When 

 rivers overflow, they always 

 leave a deposit of soil which 

 was carried by the water. 



Transported soil is any soil 

 moved from the place where it 

 was formed. It is described 

 by different names or terms, 

 depending on the means by 

 which it was transported; and 

 these different means of trans- 

 portation leave the soil in very 

 different condition as regards 

 its general nature and appear- 

 ance and use for growing crops. 

 Go out into a plowed field 

 after a heavy rain and see 



where little gulleys have been worn. Follow one of these 

 and see how much soil was carried by the water that ran 

 off. Notice the size of the particles that were carried. 



Soil deposited by water is called alluvial. It is found 

 in valleys and river-beds, beds of old lakes, ponds and 

 marshes. (Fig. 26.) 



Soil deposited from ice is called drift soil. It has been 

 formed by the action of glaciers, which are large bodies of 



FIG. 29 A large rock split by the 

 growth of a tree near Lansing, Mich. 



