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Comparative test of phosphates, Dwarf Essex rape. Cubic capacity of pots, .545 cubic feet; 

 weight of earth, about 17 kilograms at 12 per cent, moisture. All pots received equal and 

 abundant nitrogen and potash. Where supplied, phosphoric acid per pot equals .41 gram. 

 From right to left: no phosphate, dissolved bone black, acid phosphate, dissolved bone, 

 steamed bone meal, South Carolina rock phosphate, Florida rock phosphate, basic slag 

 phosphate (meal). 



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Comparative test of phosphates. Dwarf Essex rape. Cubic capacity of pots, .545 cubic feet; 

 weight of earth, about 17 kilograms at 12 per cent, moisture. All pots received equal and 

 abundant nitrogen and potash. Where supplied, phosphoric acid per pot equals .82 gram. 

 From right to left: no phosphate, dissolved bone black, acid phosphate, dissolved bone, 

 steamed bone meal. South Carolina rock phosphate, Florida rock phosphate, basic slag 

 phosphate (meal). 



