246 THE ESSENTIALS OF AGRICULTURE 



Kentucky, Tennessee, and Virginia. Aside from the fact that 

 the tobacco is air-cured, the methods of production are about 

 the same as for the fire-cured export types. 



319. Export types. The distinctive export types are the dark 

 fire-cured tobaccos of western Kentucky and the adjoining 

 counties of Tennessee, central Virginia, Maryland, and eastern 

 Ohio. The fire-cured leaf is thick, heavy, dark in color, and 

 strong, and is grown on rather heavy loam soils. In transplanting 

 to the field the plants are set far apart, often in squares, and are 

 topped low. The tobacco is harvested by cutting the stalk. In 

 curing, open fires are made on the floor of the barn so that the 

 smoke comes in contact with the tobacco, imparting to it the 

 odor of creosote. Maryland tobacco is grown on light sands 

 and sandy loams, and the leaf is mild and light in body and 

 color. Cultural methods resemble those of the cigar-leaf and 

 Burley districts. 



320. Soil depletion. It is generally supposed that tobacco 

 culture exhausts the fertility of the soil more rapidly than do 

 other farm crops. In many tobacco-growing regions little rota- 

 tion of crops is practiced and too little attention is given to re- 

 plenishing the soil. Before farmers had learned how to rotate 

 their crops and to use commercial fertilizers as successfully as 

 they now do, the tobacco soils of some districts became so 

 exhausted that tobacco growing was discontinued and the land 

 planted to other crops or allowed to become covered with weeds 

 or timber. Any one-crop system of farming depletes the soil, 

 especially under such constant tillage and clean culture as are 

 practiced in growing this crop, and tobacco has furnished an 

 excellent illustration of the results of such farming. Proper rota- 

 tion of crops, in which such legumes as clover and cowpeas 

 are important, and the replenishment of the soil by the intro- 

 duction of organic matter by plowing under green crops and 

 barnyard manure, will bring good returns in an increase of 

 the tobacco yield. 



