FERTILIZERS FOR COTTON 57 



Potash. Potash is more directly effective 

 in developing the fruit and adds to the vigor of 

 the plant. It is seldom deficient in soils and 

 especially in the soils of the Gulf States. It is 

 obtained from the following sources : 



TABLE V. POTASH CONTENT OF IMPORTANT FERTILIZER 



MATERIALS 

 SOURCE 01 POTASH PER CENT I SOURCE OF POTASH PER CENT 



Kainit . . . . 12.5 Sulphate of potash 53 



Muriate of potash . 50.0 Wood ashes . . 5 to 20 



It should be understood that the fertilizing 

 content of all the above-named materials are 

 not readily available for the use of the plant. 

 The amounts available should always deter- 

 mine the value of the material. An example to 

 illustrate may be found in acid phosphate. 

 The total content of the ground rock is twice 

 that of dissolved rock, but such a large per cent, 

 of the ground rock is unavailable that it might 

 be cheaper to buy the dissolved rock at twice 

 the price per ton. The same principle applies 

 in a greater or less degree to all the other 

 materials used in making commercial fertilizers. 



What Fertilizer to Buy. Since the elements 

 of plant food already mentioned are required in 



