346 THE FORAGE AND FIBER CROPS IN AMERICA 



being continuously kept in cotton. Since the bur clover re- 

 seeds itself each year, there has been no expense except for the 

 original cost of the seed. 1 



439. INFLUENCE OF COMMERCIAL FERTILIZERS. "Since the close of the 

 Civil War to the present time practically all of the cotton cultivated in the 

 United States, with the exception of comparatively small quantities grown on 

 the alluvial soils of great river bottoms and occasional areas of newly-cleared 

 land, has been fertilized with concentrated manures. Probably upon no other 

 crop to which they have been applied have these manures exercised so great 

 an influence as upon cotton. Not only were profitable crops made with them 

 upon lands which without them it would not have paid to cultivate, and an 

 immense area of worn-out land thus redeemed to culture, but the stimulant 

 effect of the manure so shortened the period of growth and maturity of the 

 plant that the climatic limit of culture was extended. Cotton soon came to 

 be grown abundantly over large regions where, previous to the introduction 

 of such manures, killing frosts intervened before the maturity and fruitage 

 of the plant. The enormous increase in the cotton production of the United 

 States since 1860 is undoubtedly to be credited chiefly, if not exclusively, to 

 the use of concentrated manures." 2 



440. Carriers of Fertilizing Ingredients. Kainit is the most 

 common form for supplying potash to cotton. When it can be 

 purchased as cheaply compared with the potash contained, it is 

 considered rather more desirable than the refined muriate of 

 potash, since the larger bulk and mechanical condition permit 

 its more even distribution by the fertilizer drill. 



Most of the experiment stations in the cotton states have 

 compared nitrate of soda with cotton-seed meal as a 

 carrier of nitrogen for cotton and find that they are 

 substantially equal pound for pound of nitrogen contained 

 therein under the conditions which they are ordinar- 

 ily used. Since the cotton-seed meal furnishes the nitrogen 

 at less cost, it is generally recommended and used. The Georgia 

 Station, however, recommends whether cotton-seed meal or 

 other fertilizers are used that 20 to 30 pounds of nitrate of soda 

 per acre be used when seed is planted. Soluble and reverted 

 forms of phosphoric acid seem to have given better results than 



iU. S. Dept. Agr. Yearbook 1905, p. 202. 



2U. S. Dept. Agr., Off. Expt. Sta. Bui. No. 33 (1896), p. 172. 



