130 
COTTON 
bone," "fine ground bone," "bone dust," "bone 
meal," "dissolved bone," are terms to indicate 
the mechanical treatment and physical condition 
of the fertilizer. Ground bone contains from 2 to 4 
per cent of nitrogen, and 20 to 35 per cent of 
phosphorus; steamed bone from 1 to 2 per cent of 
nitrogen and 25 to 30 per cent of phosphorus ; and 
dissolved bone 2 to 3 per cent of nitrogen and 12 to 
14 per cent of available phosphorus. 
POTASSIUM 
Potassium, the last of the elements likely to be 
deficient in the land, seems to be less urgently 
in demand by the soils of the Cotton Belt than 
are nitrogen and phosphorus. Its best use is in 
connection with phosphorus. 
The principal commercial materials that furnish 
this element are obtained from potash mines at 
Strassfurt, Germany. Potassium either in kainit 
or muriate of potash is rapidly soluble in water and 
equally available to the cotton plant. 
Kainit: — This substance is the one most com- 
monly used as a potassium carrier for cotton. It 
contains 12J per cent of potassium or 250 pounds 
to the ton. 
Muriate of Potash: — This is a purified substance 
of the potash mines, and is one of the richest 
materials supplying potassium. It contains fifty 
per cent of potassium or 1000 pounds to the ton. 
BUYING COMMERCIAL FERTILIZERS 
Commercial fertilizers make up the bulk of our 
purchased cotton manures. They are sold under 
hundreds of names, but are valuable only in pro- 
portion to the amount of plant food they contain. 
Of course, one should always be guided in 
