40G 



SOUTHERN FIELD CROPS 



sate for the greater cost of growing cotton in tlie presence 

 of tlie boll-weevil. This insect brings about a revolution in 

 agricultural methods. While the first effects are disastrous, 

 the country in time recovers its usual range of prosperity. 



373. Loss from burning cotton stalks. — As a means 

 of depriving the boll-weevil of its food, the burning of the 

 cotton stalks in the fall is generally recommended. This 

 decidedljr reduces the damage done by the weevil to the 

 next crop on the same land. Since Southern soils are almost 

 universally in need of vegetable matter, the necessitj' for 

 burning cotton stalks is to be regretted. Should thorough 

 deep plowing under of stalks prove effective, it would be 

 far preferable. The loss of vegetable matter and of plant 

 food by burning are considerable. 



374. Pounds of vegetable matter, nitrogen, phosphoric 

 acid, and potash in the stems, roots, and burs on an acre 

 yielding 300 pounds of seed cotton: — 



At the usual prices of commercial fertilizers this rep- 

 resents a loss per acre by burning stalks of aliout SI. 50 for 

 nitrogen, or a total of about 12.75 for all three constituents. 

 The humus and the nitrogen are completely lost, and the 

 potash and phosphoric acid are practically lost, since they 

 are concentrated in the spots where the stalks are burned, 



