CULTIVATION. 11 



In the United States, several rows of pole beans, i. e. 

 scarlet runners, a few steps apart, are sometimes planted 

 as a wind-screen. 



Manure. — In its natural state, the soil will rarely possess 

 the elements of plant food in such a form as is most con- 

 ducive to the production of a fine tobacco-leaf. Any 

 deficiency must be supplied in the shape of suitable 

 manure. Schlosing found that a bad burning tobacco was 

 produced on a soil containing little potash, on unmanured 

 soil, on soil manured with flesh, humus, calcium chloride, 

 magnesium chloride, and potassium chloride. A good 

 burning tobacco was produced on a soil manured with 

 potassium carbonate, saltpetre, and potassium sulphate. 

 More recent experiments carried out by other investigators 

 tend to corroborate these conclusions. It is generally 

 assumed that a soil rich in nitrogenous organic matter 

 produces a strong tobacco that burns badly. 



The results of Nessler's experiments clearly show that 

 it is not sufficient to apply the element most needed by 

 the plant — potash — in any form, but that, to produce a 

 good tobacco, it is necessary to apply it in a particular 

 combination. It was found that potash carbonate applied 

 as manure produced the best tobacco : it burned for the 

 longest time, and its ash contained most potash carbonate ; 

 whereas potash chloride produced a much inferior tobacco. 

 The assertion of other experimenters that chlorides pro- 

 duce a bad tobacco is thus confirmed. Potash sulphate 

 and lime sulphate produced a good tobacco. It may be 

 noticed here that tobacco which was manured with gypsum 

 contained a great amount of potash carbonate in the ash, 

 probably due to the fact that gypsum is a solvent for the 



