127 



THE EXPORTS OF JAMAICA IN RELATION TO 



THE SOIL. 



By H. H. Cousins, M..\. (Oxon.), F.^.S., Island Chemist. 

 AVhen the writer came out to Jam tica a f -w yea s ago, he was led 

 to believe th it the cultivated soils of the isla 'd had been seriously re- 

 duced in fertility by prolonged cropping under tropical conditions and 

 that the problem* of remedying thi^ defijiency by the general use of fer- 

 tilizers would form the chief subject of his investigations Typical 

 soils from all the chief areas of cultivation have now been analys d 

 and manurial experiments have boen carried out 0:1 m 'ny types of 

 land The general conclusions to be dra vn from these pr limiuary 

 results are (i) most of the Jamaici soils now in cultivation present n 

 high standard of fertility on analysis (2) Fertilisers have only been pro- 

 ductive of result- on soils that have b.-en under prolonged cultivation, 

 and thea only under favourable conditions of rui if Jl or of irrigation. 



In the present article an attempt will be made to set forth the 

 ac ual drain on the mineral elements of the soil fertility of Jamaica 

 by the annual removal of Phosphoric A id and Potash in the Exports 

 ol the island. 



Ttie last report of the Collector General gives an itemised account 

 of the Exports f r the five years 1899-1903. 1 have averaged these 

 figures and taken them for the basis of a calculation as to the annual 

 amount of Potash and of Phosphoric Aci 1 sent away from the island 

 in its Exports 



Representative samples of 31 of the total number of 35 varieties of 

 Exports scheduled were kindly obtained for the Department by Mr. 

 liarclay, and the Potash and Phosphoric Acid therein has been deter- 

 mined. In the case of live aninials an estimate based upon established 

 data has been made. 



The analyses are the work of. Mr. II. S. Hammond, F.C S. 

 A table has been prepared showing the value and weight in pounds 

 ol each article of export, the percentage of Potash and of Phospho;ic 

 Acid, the Pounds of Potash and Phosphoric Acid and the value of 

 these ingredients at current fert User rates reckoned as a percentage 

 tn the value of each article of export. 



The Exports are ranged in the order of their financial value. 

 Bananas le ding wit i Sugar in the seco id place and Kola Nuts in the 

 lowest position. 



'I'hese figures show that our total Exports waigh 706,7l9,3931bs. 

 (353,360 short tons) of a v lue of £1,S0G,4.2. The average percent- 

 age of Potash amounts to 405 per cent, and of Phosphoric Acid to 

 0.126 per cent., with a total content of 2,865, 5i2lbs. of Potash and 

 896,71 ^Ibs. of Phosphoric Acid. At current fertiliser rates the cost 

 of importing these constituents into Jamaica would amount to £36,000 

 per annum equivalent to a rote of 1.95 per cent on the total value of 

 the Exports. 



Broadly charging this lo-s to the cultivated area of the island, 

 which, for the period under review, is estimated at 700,000 acres, it 

 would appear that our Exports, when assessed as an acre.ige charge, 

 amount to £2 lis. 6d per acr.^ in value of produce and at a charge of 

 4lbs. of Potash and l^lbs. of Phosphoric Acid to the soil, the cost of 



