CROPPING SYSTEMS, FERTILIZERS FOR CORN 229 



fertilizer will maintain the normal soils of the cotton-belt 

 at a high level of productiveness. ' 



(3) Nitrogen is too expensive to purchase in commercial 

 fertilizers to supply the entire needs of the corn crop. It 

 sl\ould be supplied by growing^ legumes and applying 

 barnyard manure. 



(4) It seldom pays to use fertilizers, (a) where corn is 

 grown continuously; (b) on lanld that is deficient in organic 

 matter; (c) on land that has been poorly prepared. Under 

 such conditions a relatively small percentage of the fer- 

 tilizer is used by the crop. 



