524 SOUTHERN FIELD CROPS 



of exchange, taking the place of money. Tobacco is now 

 extensively grown in certain restricted sections from Con- 

 necticut to Texas. Among the Southern States Kentucky 

 is the largest producer, followed by Virginia and North 

 Carolina. In recent years, the production of a high-grade 

 cigar tobacco has become a leading industry in the north- 

 ern part of Florida and in other localities in the Gulf States. 



510. Composition. All kinds of tobacco contain vary- 

 ing quantities of the narcotic alkaloid, nicotine, which is 

 a recognized poison. The heavier and stronger the leaf, 

 the larger, as a rule, is the proportion of nicotine. 



All parts of the tobacco plant are rich in potash and 

 nitrogen and also contain considerable amounts of phos- 

 phoric acid. Tobacco is an exhausting crop. 



511. Soils and their relation to types of tobacco. 

 None of the ordinary crops of the farm is so much influ- 

 enced in quality by the soil on which grown as is tobacco. 

 For this reason tobacco culture is largely confined to re- 

 stricted areas and to particular soils. An exact de- 

 scription of the soils suited to each type is not easily 

 made. In general, cigar tobacco and other kinds in 

 which a thin leaf is desirable succeed best on rather 

 light or sandy soils. On the other hand, heavy or 

 dark tobacco is best suited to stiff er land. Burley tobacco 

 is grown almost exclusively on limestone soils, chiefly in 

 Kentucky and adjacent states. 



For most grades of tobacco, newly cleared land is pre- 

 ferred, since an abundance of humus is desirable. For 

 this reason, growers of this crop have cleared .most of the 

 forests from the best soils of the tobacco districts. 



The' dark export tobacco of Virginia is largely grown 



