16 AGRICULTURE 



The soils of New England are nearly all drift or alluvial; those 

 of the Southern states are alluvial or sedentary. 



Soil Fertility. Left to the processes of nature, as a rule, soil 

 becomes more fertile, more productive, year by year. Is this the 

 case when it is cultivated by man ? It ought to be. Good farming 

 maintains and increases the fertility of soil. This fertility, or 

 productive power, is well termed ' the farmer's capital.' If his 

 methods are good, he preserves and increases the fertility of 

 his land. He draws a large interest in good crops, and adds to his 

 capital. Thus year by year he and his farm are enriched. If 

 his methods are' bad, his crop lessens his capital; every year his 

 farm grows poorer, and so does he. 



Methods in America. There are to-day in the United States 

 thousands of acres of ' worn out ' land which fifty years ago were 

 cultivated fields and a hundred years ago were forests. On the 

 other hand, there are thousands of acres which industry and skill 

 have reclaimed from barrenness and made productive. 



EXPERIMENTS 



1. Put some clean stones in water. Let the water freeze and then 

 expose it to heat. Repeat several times and then examine it. What 

 causes the sediment at the bottom? 



2. Scrape lichens from a stone. Compare it with a freshly broken 

 rock. Notice how the lichen-covered stone is marked and furrowed. 

 Why is this ? 



3. Stir into a pint of clear water as much clay as it will dissolve. 

 Let it settle, and then measure the sediment. What does this show 

 as to the soil-bearing power of water? 



FARM SOILS 



Let us examine three substances which we may regard as the 

 basis of soils. These three substances are sand, clay, and hu'mus. 



