SCIENCE IN ITS APPLICATION. 89 



lime 99 pounds, and phosphoric acid 13 pounds, in the 

 leaf and stalk. 



It also appears that the stalks in such an acre of 

 Connecticut tobacco weigh, at the time of cutting, 

 about 9500 pounds, of which about 8300 pounds is water. 

 Two-thirds of this is evaporated in curing, and the rest 

 is carried back to the field in the cured stalks. The 

 later the crop is cut, the more nitrogen and mineral ele- 

 ments it contains ; stalks cut on August 22 contained 

 26 pounds of nitrogen per acre, which increased to 42 

 pounds when not cut until September 7. Like gains 

 occur in Virginia and other types of tobacco. No deter- 

 mination is at hand of the amount of plant food in the 

 roots of such a Connecticut crop as that above named, 

 but the Virginia crop of 1000 pounds leaf per acre con- 

 tains in its roots, of nitrogen eight pounds, potash seven 

 and one-half pounds, lime five and one-half pounds, 

 phosphoric acid and magnesia, one pound each. 

 Whatever plant food the roots contain, of course, remains 

 in the soil, and it is not necessary to consider it after 

 the first season, but on new land, sufficient plant food 

 must be present to develop the roots freely, in addition 

 to the other parts of the plant. In any rational system 

 of tobacco culture, the stalks are always returned to the 

 soil as fertilizer ; hence the only fertility really lost is 

 that sold in the leaf. 



But since the entire plant must be fed, the necessity 

 of large quantities of plant food is at once apparent, for 

 everything essential to the perfect development of every 

 part of the plant must be present in the soil in a thor- 

 oughly available condition. The demands of touacco can 

 be better appreciated by comparing it with other leading 

 field crops. And since cigar leaf is grown under the 

 highest state of cultivation and with a lavish supply of 

 fertility, it is only fair to use for comparison other crops 

 grown under similar favorable conditions. Prof. John- 



