The Barbados Sugar Cane Experiments. 355 



recovered in the produce, whilst where 80 lbs. were 

 used 30*8 lbs. were recovered. If, however, we calculate 

 the amount recovered, not on the average increased yields 

 obtained by addition of nitrogenous manures, but only 

 upon the very concordant results obtained in the crops of 

 1888 and 1890, during the growth of both of which the 

 climatic conditions were most favourable for nitrogenous 

 manurings, with the manure the nitrogen of which the 

 cane appeared to make the most complete use of, we find 

 that the increase due to manuring with 40 lbs. of nitrogen 

 applied as sulphate of ammonia was .23,979 ^b^., and 

 that with 80 lbs. was 43,587 lbs. In the produce of the 

 first there were recovered i8*oi lbs., and in that of the 

 second 51.95 lbs., or 45 and 65 per cent, of the added 

 nitrogen respectively, as compared with the 68 per cent, 

 stated by Dr. Wagner to be recoverable in the produce 

 of many European crops.* 



Experiments with Phosphates. 



These experiments were made with the objeft of ascer- 

 taining the importance of phosphoric anhydride as a con- 

 stituent of sugar cane manures, the proportions of it 

 most advantageous, and as to whether insoluble phosphate 

 of lime could, with advantage, supersede the use of 

 superphosphate of lime. The portions of the fields upon 

 which these experiments were carried out are consider- 

 ably more fertile than those used with the experiments 

 with nitrogen, producing on an average four tons of 



* The relatively high proportion of nitrogen recovered where 80 lbs. 

 had been applied was due not so much to the increased yield as to the 

 high proportion of nitrogen present in the whole of the produce. 



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