FERTILIZERS AND FERTILIZING. 3Q5 



super-phosphate, 13 to 15 per cent, available; a 

 high-grade super-phosphate, 16 to 19 per cent, available; 

 and double super-phosphate, 45 to 57 per cent, available. 



The readiness with which the phosphoric acid may 

 be obtained from bone depends largely upon the fineness 

 of division of the particles. The finer it is ground, the 

 more readily the roots of the tree can take it up. It must 

 undergo decomposition before yielding up its phosphoric 

 acid and for this reason it is not well to use it where 

 quick results are desired. It is an excellent substance 

 to use to increase the phosphoric acid content of the soil, 

 supplying a store from which the tree may draw gradually. 

 Its use is strongly recommended at the time of planting 

 citrus trees. A pound or two incorporated with the soil 

 before placing it about the roots, is an excellent practice. 



For general use in citrus fertilizers, dissolved bone 

 is the best of the materials derived from bone to use. 

 contains, as already noted, from 16 to 19 per cent. o1 

 available phosphoric acid. 



Phosphoric acid fertilizers derived from phosphate 

 rock are of two kinds : super-phosphate, known to the 

 trade as acid phosphate or high-grade acid phosphate 

 and double super-phosphate. The latter is not 

 used to any great extent. It has been claimed 

 that it is best to use dissolved bone as a source 

 of phosphoric acid, and yet acid phosphate has been used 

 in some groves in Florida continually for ten or fifteen 

 years with uniformly satisfactory results. Each year 

 the crops have been all that could be desired. 



In the face of results obtained from the use of either 

 dissolved bone or acid phosphate, we are probably safe 

 in saying that one is as good as the other as a source of 

 phosphoric acid. 



