92 ELEMENTARY AGRICULTUEE 



cowpeas have been growing. (Fig. 53.) The reason 

 is that the millions of bacteria have been at work 

 npon their roots, storing up nitrogen for them and 

 for other plants to feed upon. This explains why 

 farmers use these crops to build up worn-out soils. 



Growing Several Crops. The farmer always raises 

 some crops that pay better than others. Corn may 

 pay better than oats, and yet it is wise to grow some 

 oats, because the two crops can be worked at differ- 

 ent times. A farmer may raise all the corn he has 

 time to take care of and still raise a field of oats 

 besides. Barley, oats, and spring wheat require 

 attention at the same time. So the farmer usually 

 chooses only one of these crops. Eye and winter 

 wheat must be worked at the same time, and so the 

 farmer grows but one of these in a season. 



Not Too Many Crops. It is better to raise a num- 

 ber of crops than to put the whole farm into one, 

 because the farmer wishes to provide work for him- 

 self and his laborers all the time. It is not well, 

 however, to have too many crops, because they may 

 call for too much machinery. A farmer can not 

 afford to buy the necessary tools for potatoes or 

 wheat or orchards unless he has a fair-sized field 

 in such crops. But small vegetables and fruit for 

 home use should all be raised on every farm in 

 gardens and small orchards. 



Rotation of Crops. Eotation means that the crops 

 grown on each field are changed every year or two. 

 Nearly every successful farmer does this. Still 



