20 



Percentage and Character of Plant Food. 



The percentage of the various forms of plant food in high and low analysis complete 

 mixed fertilizers is shown in the following table: — 



Form of Plant Food. 



Percentage 



in High Analysis 



Brands (14 per 



cent or over of 



Available 

 Plant Food). 



Percentage 



in Low Analysis 



Brands (Under 



14 per cent 



Available 



Plant Food). 



Total nitrogen 



Nitrogen as nitrates and ammoniates . 



Water soluble organic nitrogen 



Active water insoluble organic nitrogen 



Inactive water insoluble organic nitrogen 



Total phosphoric acid .... 



Available phosphoric acid 



Insoluble phosphoric acid 



Potassium oxide 



2.24 



.96 



.40 



.47 



.41 



8.69 



7.14 



1.55 



2.67 



(a) Nitrogen. 



In high-analysis fertilizers, about 57 per cent of the total nitrogen was in mineral 

 form, — that is, was derived from nitrates and ammoniates, — and about 87 per cent 

 of the total nitrogen was found active. In low analysis fertilizers, 43 per cent of the 

 total nitrogen was in mineral form, and 82 per cent of the total nitrogen was active. 



