COCONUT PLANTER'S MANUAL. 99 



It can be used with advantage in soils poor in lime and phosphoric acid, 

 especially in conjunction with green manuring. On pure sands without 

 green mauures, the lime would be better applied as ground coral lime. 



Superphosphate consists of bone or other phosphates which have been 

 treated with sulphuric acid to render the phosphoric acid soluble. Ordinary 

 superphosphate contains no nitrogen, but 18 per cent, of phosphoric acid 

 and a good proportion of sulphate of lime, which, as I have said, may be of 

 special value to the growth of the palm. It is suitable for application to 

 all the soils ; but when poor in lime, they should receive au application of 

 ground or slaked joral lime previous to the manuring. 



Of the potash salts, the muriate contains 58 per cent, pure potash 

 compared with 50 per cent, in the sulphate, both costing the same. 

 For soils poor in sulphuric acid, and most of them are, the sulphate is pro- 

 bably better. It is slowly soluble in water and after rain would soon be 

 diffused throughout the soil. 



Kainit is another potash salt frequently employed. It contains only 12 

 per cent, potash but a considerable amount of salt and gome magoesium 

 salts. These are very hygroscopic and are thought to assist in absorption of 

 atmospheric moisture during a dry period. A pound of potash costs 50 per 

 cent, more than the potash in the muriate or sulphate. 



If mixed with basic slag as is commonly done, it should be applied at 

 once, or kept in a dry place ; otherwise the slag will set like cement and be 

 rendered useless. 



Nitrogenous manures consist of the organic manures such as cakes, 

 blood, and fish and for this reason are valuable on soils poor in humus. The 

 nitrogen is insoluble in water, but as the manures decompose, it is gradually 

 converted into ammonia and nitric acid which combines with lime and can 

 then be absorbed by the roots, chiefly as nitrate of lime. 



The cost of nitrogen per pound varies and has risen considerably in 

 recent years. It now costs 75 cents per lb. in nitrolim and sulphate of. 

 ammonia, but from one rupee and over in cakes. 



Blood meals contain from 11 to 12£ per cent of nitrogen and are mere 

 rapidly decomposed than cakes, but the pound of nitrogen now costs Rs. 1*12 

 compared with Rs. 1*30 in castor cake. 



The nitrates are all very soluble in water and have to be used with 

 caution. They should not be applied during or just before the wet season ; 

 otherwise s me loss is bound to result, but a certain amount can frequently 

 be employed in mixtures with advantage. The cheapest source of nitrogen 

 available at present is in nitrolim, which is a manure formed from the 

 nitrogen of the air. It contains from '20 to 24 per .cent, of free lime and 

 18 per cent, of nitrogen, and has a strongly alkaline reaction like basic 



