6 SOUTHERN FIELD CROPS 



From the above table it may be seen that the oat plant 

 makes considerable demands on soil fertility; that the 

 greater part of the nitrogen and of the phosphoric acid is 

 removed by the grain; and that by far the greater part of 

 the potash is removed by the straw. 



These figures should impress the fact that the straw 

 should be returned to the land in the form of stable manure, 

 after having been used either as food or bedding. In case 

 it is impracticable to make either of these uses of the straw, 

 the stacks should not be burned nor left to rot in one 

 place, but immediately or after partly rotting the straw 

 should be distributed over the galled spots in the fields. 



In spite of the fact that a good crop of oats, if the straw be 

 carried off, removes a considerable amount of plant-food, yet ex- 

 perience shows that the occasional introduction of an oat crop 

 into the rotation increases the yield of succeeding crops. This 

 is chiefly because of the vegetation occupying the land after oats 

 are harvested. Even the growth of a mass of weeds may be help- 

 ful to some soils. However, the oat crop gives opportunity to 

 improve the land still more rapidly, due to the succeeding growth 

 of cowpeas, which is usually the best crop to follow oats. 



Varieties 



9. Types of Southern oats. — In Europe, Canada, and 

 the northern part of the United States, the niunber of 

 varieties of oats in cultivation is considerable. However, 

 nowhere does the number equal that of varieties of wheat. 



In the Gulf States, few varieties of oats are grown. The 

 types most commonly raised in the South are: — 



(1) Red Rust-proof; 



(2) Burt; 



(3) Turf or Grazing. 



