328 SOUTHERN FIELD CROPS 



meal, the former may be profitably employed on cotton. 

 The farmer should buy either nitrate of soda, cotton-seed 

 meal, dried blood, or tankage, choosing that one in which 

 a pound of nitrogen costs least. Most experiments fail to 

 show any notable difference in the value of a pound of 

 nitrogen from these different sources. 



298. General need of cotton soils for nitrogen. — 

 Cotton-seed meal or other nitrogenous fertiUzer is highly 

 beneficial to cotton on a large proportion of the culti- 

 vated area of every region where the soils have become 

 poor. Apparently it is almost universally needed on 

 ■uplands in such regions except on (1) new grounds, and 



(2) on soils containing considerable vegetable matter, as 

 the result of proper rotation with cowpeas, oi: other humus- 

 forming crops. Although cotton-seed meal is almost 

 universally beneficial, it is not always profitable when 

 applied to cotton at the rate of 200 pounds or more 

 per acre. Poor physical condition of the land, resulting 

 in a scarcity of moisture in the summer, is the greatest 

 hindrance to the profitable use of large apphcations of 

 cotton-seed meal. But even with poor physical con- 

 dition, it is usually profitable on soils where the stalk is 

 small to supply nitrogen in the mixed fertiHzer for cotton. 



299. Cost of a pound of nitrogen. — A pound of nitro- 

 gen in commercial fertilizers usually costs 15 to 18 cents. 

 To learn the average cost each year, inquiry should be 

 made of the State Commissioner of Agriculture, in the 

 capital city of the state. 



300. Fertilizing value of cotton-seed meal and hulls 

 before and after being fed. — In an experiment at the 

 South Carolina Experiment Station a definite amount 



