50 MANUAL FOR SUGAR GROWERS. 



Experimental Station, Barbados, 1889, etc.) He 

 found the amount of phosphoric anhydride to range 

 from 23.5 pounds with a crop of 22.3 tons of cane, 

 to 45.3 pounds with a crop of 32.5 tons, j)er acre. 

 The potash varied from 55.5 pounds with a crop of 

 28.5 tons of cane per acre, to 116 pounds with a 

 crop of 38.8 tons per acre. These figui-es deal with 

 the potash and phosphoric acid in the canes only, 

 irrespective of the amount in the tops. The tops 

 will contain about nineteen or twenty pounds of 

 phosphoric anliydride, and seventy to seventy-five 

 pounds of potash, but on a well-conducted estate 

 these will ultimately find their way back to the soil 

 after having been used for food for the working 

 stock. A certain amount of the potash and phos- 

 phate, too, will be returned to the soil in the ashes 

 from the furnaces and in the scums removed from 

 the juice, so that, making allowance for these, the 

 quantity of plant-food removed from an acre of land 

 by an average crop of say twenty-five tons of cane 

 per acre will be about fifty pounds potash, twenty- 

 five pounds phosphoric anhydride, and seventy 

 pounds of nitrogen per acre ; these amounts of 

 plant-food will be contributed to the soil by the 

 methods of manuring here recommended, and this, 

 with good and careful tillage, should, under reason- 

 ably favourable circumstances, produce satisfactory 

 crops. 



Weeding is an operation which will occupy much 

 of the planter's time and care. This operation has 

 a beneficial action for several reasons : not only are 

 weeds killed and the ground left unencumbered for 



