21 



they are ready for the market. The nitrate is at present sold for the 

 manufacture of powder, and brings 5 cents (gold) per pound. 



These deposits were probably caused by the leaching of the upper 

 valley soils by the irrigation water and river drainage. The potash and 

 other salts contained in the waters were finally deposited in the lower 

 levels of the valley near the coast. 



BAGASSE ASHES AS FERTILIZER. 



As the cane contains a considerable amount of potash in its ash 

 (18 to 24^), the bagasse would naturally have a potash as well as 

 phosphoric acid value. If the bagasse were burned so that there 

 would be a gradual but complete incineration, the percentage of 

 available potash would be comparatively high. The percentage of 

 ash in the bagasse is about. 1.25%, and the percentage of bagasse 

 from the present type of mills is 32 to 34 ^, so that the actual 

 amount of available potash for an estate grinding 120,000 tons of 

 cane would be considerable. 



Few bagasse furnaces give an ash containing all its potash in an 

 available form. This is shown by the presence of a quantity of slag 

 which would have little influence if applied to the soil. 



The application of bagasse ashes from most of these furnaces must 

 not, therefore, be considered as having a fertilizing value equal to the 

 same amount of carefully incinerated bagasse. 



The following analysis shows the proportion of elements in the 

 bagasse ashes of some Peruvian cane: 



Analysis of Bagasse Ashes. (Hda. Cartavio) 



Sand, etc. 64.76 Oxide of Sodium 3.47 



Coloid silica 0.73 Carbon etc. (difference) 1.77 



Phosphoric Acid 3.64 



Chlorine 1.37 100.62 



Sulphuric Acid 5.34 



Oxide of Iron etc. 1.70 Less Oxygen Chlorine 0.62 



Oxide of Calcium 3.52 



Oxide of Magnesium 2.42 100.00 



Oxide of Potassium 11.90 



