10 Jan., 1919.] Fertilizers Registered for 1919. 



57 



Basic Phosphate. 



This fertilizer is of recent introduction, and owes its appearance 

 on the list of published brands to the shortage of supply of Thomas 

 Phosphate. It is prepared locally by mixing superphosphate with 

 sufficient lime to neutralize all the free acid, and convert the super- 

 phosphate into a less soluble form. Superphosphate so treated contains 

 its phosphoric acid mainly as citrate soluble, and thus bears some 

 resemblance to Thomas Phosphate, but differs therefrom, however, in 

 the degree of fineness of its particles, being much coarser grained. The 

 finer the particles composing a fertilizer, the more surface will be exposed 

 to the action of the various agencies in the soil. Superphosphate, when 

 applied to the soil, undergoes a process of reversion. The phosphoric 

 acid of the superphosphate is mostly soluble in water. When super- 

 phosphate is applied to land, the soil water will dissolve the phosphate, 

 and bathe, within certain limits, the particles of soil it may reach. 

 Meeting with small particles of lime, iron, and alumina oxides, it 

 enters into combination with them, and reverts to a less soluble 

 condition, and is deposited as a thin coating. A more intimate mixture 

 is obtained with the soil by superphosphate than would be got through 

 the use of basic phosphate. Further, as this fertilizer is prepared by 

 mixing lime with superphosphate, it is reasonable to suppose that no 

 advantage is to be gained by substituting this fertilizer for superphos- 

 phate on soil containing a fair percentage of lime. 



Fertilizers Act 1915. 

 TABLE OP UNIT VALUES FOR THE YEAR 1919. 



Nitrogen, as Ammonia 

 „ Blood . . 



„ Fine bone, and Bone and Blood 



„ Bone and Animal Fertilizers 



„ Coarse bone 



Phosphoric Acid, as Water Soluble 



„ „ Citrate Soluble, and as fine bone 



Citrate Insoluble in roasted and intensely ground Phos- 

 phate . . 



Coarse bone 



Citrate Insoluble in Bone Fertilizers, Bone and Super, 

 and Super and Bone 



Citrate Insoluble in Supers, Nitro-supers, and Basic 

 Phosphates 



Citrate Insoluble in ground rock phosphates . . 



4 3 



3 6 



1 



2 



