CULTIVATION. 27 



strated, and is therefore equivalent to an application of 

 potash, provided the latter actually exists in the soil. 



" Potash is exported in the tobacco crop to the amount of 

 70-80 Ib. per acre yearly, and is required for the stalks to 

 the extent of some 50 Ib., making a total of 120-130 Ib. 

 As already intimated, potash does not commonly waste 

 from the soil by washing. It is seldom found in appre- 

 ciable quantity in well or drain water, and most soils 

 absorb it and fix it so firmly that water can remove it but 

 very slowly. It does, however, appear in the drain water 

 from very heavily dunged fields, though in small propor- 

 tion. Stable or yard manure on the average contains one- 

 half per cent, of potash, or 10 Ib. per ton. Twelve or 

 thirteen tons of stable manure would therefore contain the 

 potash needful to produce a crop. The dressing of 20 tons 

 of 10 cords of stable manure, per acre, which is often 

 employed on tobacco, is doubtless enough to fully supply 

 the crop, and the application of additional potash is 

 apparently quite unnecessary. The employment of potash 

 salts upon tobacco lands would therefore seem to be 

 uncalled for unless the amount of stable manure is greatly 

 diminished, or its quality is very inferior. In case potash 

 salts are to be applied, the best form to make use of is 

 potash sulphate, of which 250 Ib. contains 135 of potash. 

 Next to this is probably potash carbonate, i. e. the ordinary 

 potash of commerce, which contains some 70 per cent, of 

 potash ; 200 Ib. of this would be sufficient for an acre. To 

 apply it I would suggest breaking it up into small pieces 

 and soaking it in two or three times its weight of water 

 until the lumps crush easily, and mixing these with so much 

 ground gypsum as will make a mass dry enough to handle. 



