162 



THE COCO-NUT 



CHAP. 



leguminous plants which, with the excreta of the stock, 

 will maintain or even increase the soil's natural wealth 

 of nitrogen. Either as pasture or as a crop to be turned 

 under there are various legumes which will accomplish 

 this end. Even the sensitive plant which, as a weed, 

 is widespread in coco-nut plantations is eaten by cattle, 

 and contributes very materially to the stock of soil 

 nitrogen. There are other legumes which in young 

 groves will return a direct profit, but these have already 

 been mentioned under the head of catch-crops. The 

 third need of the plant for a mineral food is for 

 phosphorus. There are various commercial sources of 

 which the most common is perhaps basic slag. 



The coco -nut removes, as compared with other 

 crops, but little of these elements from the soil. Aside 

 from the fertilizers which provide single food con- 

 stituents there are in general available for use on 

 coco-nut plantations the manure of live stock, and, 

 if oil is manufactured, the oil-cake of the coco-nut. 

 The manure of different animals varies in composition. 

 That of cattle contains in general terms 0*3 per cent to 

 0*5 per cent of nitrogen, 0*1 per cent to 0*2 per cent 

 of phosphorus pentoxide (commonly, but inaccurately 

 called phosphoric acid), and 0*01 per cent to 0*2 per 

 cent of potash. Cattle manure is a weaker fertilizer 

 than many people realize, and accordingly must be 

 applied in large quantities to produce conspicuous 

 results. It may then well be supplemented by the 

 application of ashes, or of a commercial fertilizer rich 

 in potash. Applied in sufficient quantities, it will pro- 

 duce results that are conspicuous indeed, as is evidenced 

 by one of our groves, a part of which has been used 

 as a corral. 



The oil-cake contains materials which ought never 

 to leave the farm unless at a profit which will permit 

 the purchase of fertilizers to replace the material lost. 

 The composition of the oil-cake of course varies from 

 place to place according to the way in which it is 

 secured. Its asl^ as a general proposition, amount^ to 



