6 AGRICULTURE FOR BEGINNERS 



food taken from the air began to grow. They grew just 

 as you now see mosses and lichens grow on the surface 

 of rocks. The decay of these plants added some fertility 

 to the newly formed soil. The life and death of each suc- 

 ceeding generation of these lowly plants added to the soil 

 matter accumulating on the rocks. Slowly but unceas- 

 ingly the depth of soil increased until higher vegetable 

 forms could flourish and add their dead bodies to the 

 deepening soil. This vegetable addition to the soil is 

 generally known as humus. 



In due course of time low forms of animal life came to 

 live on these plants, and in turn by their work and their 

 death to aid in making a soil fit for the plowman. 



Thus with a deliberation that fills man with awe, the 

 powerful forces of nature splintered the rocks, crumbled 

 them like a potter's vessel, filled them with plant food, and 

 turned their flinty grains into a soft, snug home for vege- 

 table life. 



^SECTION II TILLAGE OF THE SOIL 



A good many years ago there lived in England a man 

 by the name of Jethro Tull. He was a farmer and a most 

 successful man in every way. 



His claim to fame comes from his teaching the English 

 people and the world the value of thorough tillage of the 

 soil. Before and during his time, farmers did not till 

 the soil very intelligently. They simply prepared the 

 seed bed in a careless manner, as a great many farmers 

 do to-day, and when the crops were gathered the yields 

 were not large. 



