110 CLOVERS 



not only gather nitrogen for the fruit trees, but in 

 their decay they increase the power of the soil to 

 retain moisture for the benefit of the trees. 



Some varieties of clover may be grown as catch 

 crops, that is, as crops which are grown in addition 

 to some other crop produced the same season. When 

 thus grown, it is usually for purposes of soil im- 

 provement rather than to furnish food. The varie- 

 ties best adapted for this purpose in the Northern 

 States and Canada are the medium red and the 

 crimson, the latter being much more circumscribed 

 in the area where it will grow successfully than the 

 former. When medium red clover is thus grown, it 

 is commonly sown along with one of the small cereal 

 grains, and is buried in the autumn or in the fol- 

 lowing spring. (See page 75.) The extent of the 

 advantage is dependent chiefly on the amount of 

 the growth made, and this in turn is influenced by 

 the character of the soil, the season and the nurse 

 crop. In certain areas favorable to the growth of 

 clover some good farmers sow clover along with 

 all the small cereal grains which they grow. Crim- 

 son clover is usually sown in the late summer after 

 some crop has been reaped and it is plowed under the 

 following spring. (See page 250.) 



In the Southern States Japan clover and burr 

 clover will serve the purpose of catch crops better 

 than the other varieties. The former will follow 

 a winter crop (see page 284), and the latter a sum- 

 mer crop. ( See page 294.) 



Although alfalfa is not usually looked upon as a 

 rotation crop in the Rocky Mountain valleys, it 



