TEE EFFECT OF DECOMPOSING ORGANIC 

 MATTER ON NATURAL PHOSPHATES. 



N. T. LuPTON, State Chemist. 



FLOATS AS A SUBSTITUTE FOR ACID PHOSPHATES. 



During the past few years especial attention has been 

 called to the fertilizing value of natural or raw phosphates, 

 when applied alone in the form of floats, and when mixed 

 with organic matter, such as cotton seed and cotton seed 

 meal. If floats can be shown to produce as good results as 

 acid ulated phosphates, which is claimed by some, the cost 

 of commercial fertilizers ought to be greatly reduced and 

 the extensive deposits of soft, aluminous phosphates found 

 in Florida and elsewhere find a ready sale. While the re- 

 sults of experiments ai'e somewhat conflicting, there appears 

 to be conditions under which floats, or fine ground raw 

 phosphates do produce as good, if not better results, than 

 acid phosphates. The presence of decomposing organic 

 matter is generally regarded as the most important of these 

 conditions, but chemists are not agreed as to the precise na- 

 ture of its action. 



THE EFFECT OF NATURAL PHOSPHATES ON PLANT GROWTH, 



Liebig, in his letters on "Modern Agriculture," published 

 in 1859, advances the theory that organic matter undei'going 

 decay accumulates carbonic acid in the soil, and when rain 

 falls it dissolves the carbonic acid and thereby acquires 

 the power of taking up phosphate of lime. This carbonic 



