22 COCOA 



Per cent. 



* Organic matters and combined water . 8*035 

 Phosphoric anhydride . . . 0*120 

 Sulphuric anhydride . . . 0*028 

 Chlorine ..... traces 



Iron peroxide . . . 9*642 



Alumina . .15*403 



Manganese peroxide . 0*083 



Calcium oxide . . . .0*196 



Calcium carbonate .... 0*152 

 Magnesium oxide .... 0*160 

 Potassium oxide .... 0*097 



Sodium oxide 0*360 



Insoluble silica and silicates . 65*723 



CHAP. 



100*000 

 * Containing nitrogen . . . . 0*109 



In this soil the proportions of phosphorus, potassium, 

 calcium and nitrogen may all be said to be sufficient. 

 The amount of phosphoric anhydride (0*120 per cent) 

 is greater than that in seven out of ten soils mentioned 

 as good cocoa soils, the proportions in these seven cases 

 varying between 0*044 per cent and 0'114 per cent; 

 the amount of potassium oxide (0*097 per cent) is not 

 high, but is nearly as high as in a good Trinidad soil 

 mentioned (0*118 per cent); the amount of calcium as 

 oxide (0*196 per cent) and as carbonate (0*152 per cent) 

 is rather high, while nitrogen (0109 per cent) is present 

 to a higher degree than in some good cocoa soils (two 

 Trinidad soils mentioned as good contained 0*100 per 

 cent and 0*107 per cent). In the poor soil from 

 Grenada, already mentioned, it may be that a great 

 portion of the phosphorus or the potassium is present 

 in an unavailable form, but the figures of the analysis 

 do not furnish this information. 



In various handbooks we find the statement that 

 "the most important point chemically is that the soil 

 should contain an ample supply of available potash, a 

 fair supply of nitrogen and a medium one of phosphoric 

 anhydride and of lime." 1 This assertion may be true 



1 Hart, Cacao (1911), p. 190 ; other authors express similar opinions. 



