95 



put on, they should be used at the rate of 5 to 8 cwt. per acre, and 

 put in a trench round the bushes at about one foot from the trunk. 

 They should be guaranteed to contain 2 to 2\ per cent, of Nitrogen 

 and 12 per cent, of soluble Phosphate of Lime. Superphosphate of 

 Lime, prepared from mineral phosphate deposits, now chiefly in 

 Carolina and Florida, will also supply phosphates to the plants. It 

 is obtained from these sources in a precisely similar fashion to that 

 in which the last named manure is prepared from bones. Alone it 

 should not usually be applied, but mixed with oilcake it forms a 

 very effective manure, or indeed it might be added along with cattle 

 manure to soil deficient in Phosphates. 



The objection to all these manures made by treatment of 

 some raw product with Sulphuric Acid, is that it is apt to exhaust 

 the Lime already rather deficient in the soil, and hence, though 

 one could recommend small quantities in mixtures, they are not 

 materials to be added in large quantity. 



BASIC SLAG. 



The Phosphatic Manure which has been the most successful 

 up to date is probably Basic Slag, and in Ceylon its use has had 

 a very great extension. It has practically only been on the market 

 ten years, being a bye-product of the manufacture of steel by 

 the Basic Bessemer Process, and consists, it is supposed, of a Tetra- 

 Basic Phosphate of Lime, together with Iron compounds. It varies 

 very much in value, and should always be bought on a guarantee 

 of at least the equivalent of 35 to 40 per cent, of Phosphate of Lime, 

 and a fineness of 70 to 80 per cent, (that is to say, this percentage will 

 pass through a sieve of 10,000 meshes to the square inch). As 

 it contains an excess of lime, it cannot be mixed with or stored 

 with most other manures, and further, it is of little or no value 

 applied alone. The greatest success in Ceylon has been obtained 

 by burying light prunings in trenches with this manure, when 

 f^he rotting material thus buried becomes quickly interlaced with 

 a mass of the feeding rootlets of tea. I have seen one of these 

 trenches opened after six months, when the prunings had fairly 

 well rotted, and found this to be the case. 



BURIAL OF PRUNINGS. 



This, however, raises the whole question of the advisability of 

 burying prunings, a practice which, on the recommendation of 



