64 AGRICULTURE 



ing to the bean or clover family, require land rich in 

 lime. 



Thus alfalfa succeeds finely on the best grades of the 

 black lime or prairie lands in Alabama and Mississippi, 

 and on the similar "black waxy" lands of Texas. On the 

 same class of soil, Johnson grass hay is grown for market. 

 Red clover is adapted to the lime lands found in many of 

 the valleys in the northern parts of some of the Gulf 

 states and to limestone soils common in Tennessee, Ken- 

 tucky, and the sections to the north. 



Color of soils. If two soils are made up of particles of 

 the same size, the darker one is usually the warmer. This 

 is because dark soils, like dark clothes, absorb the sun's 

 heat. A light-colored, sandy soil, however, may be warmer 

 than a dark clay soil. 



A dark color generally indicates fertility, and is due to 

 the presence of much humus. 



EXERCISE. In your neighborhood what crops are generally grown 

 on the most sandy soil ? What use is made of the wettest land ? How 

 are clay lands utilized ? Hilly lands ? Very black lands ? What are 

 the favorite grass lands ? Orchard lands ? 



NOTE TO THE TEACHER. Write to the Bureau of Soils, Washing- 

 ton, D.C., asking for a report on a soil survey of your county, or of the 

 region most like yours. Explain to the pupils the main features of the 

 colored map in that report. 



