PARA RUBBER. 43 



elements i9 closely associated with the abundance and activity of the 

 leaves. It may appear absurd to advocate manuring with a view to in- 

 creasing what is commonly regarded as mainly a waste product, but 

 it cannot be gainsaid that abundance of cortical tissue provides 

 more cells for perforation and disintegration, processes involved in 

 the formation of the latex tubes of Para rubber. 



The analyses of various parts of the Para rubber plant, given else- 

 where, should be carefully considered when mixtures of artificial rub- 

 ber manures are being compounded. 



Forest Vegetation and Soil Improvements. 



It must be remembered that Para rubber trees form a forest 

 vegetation, and that they will grow well in relatively inferior soils, 

 providing there is a fair balance of plant food and the climatic 

 conditions are favourable. The soil under forest vegetation im- 

 proves in mechanical and chemical composition with age, owing 

 to the protection which the trees afford to the soil, to the action of 

 the roots, and the accumulation of leaf -mould. The annual fall 

 of leaf from Para rubber trees ultimately effects an improvement 

 in the soil in which the trees are being grown. This is borne out by 

 the analyses of the soils at Henaratgoda, the results proving that the 

 organic matter, potash, and nitrogen are greater in the soil which has 

 been under rubber for 29 years than that which has been under 

 pasture ; the lime and magnesia have decreased under the old rubber, 

 while the phosphoric acid is the same under both conditions. 

 Food in Para Rubber Leaves. 



The manurial value of the leaves from Para rubber trees cannot be 

 doubted when it is remembered that the material, dried at 100° C, 

 contains 172 per cent, of potash, 3 - 44 per cent, of nitrogen, 06 per 

 cent, of phosphoric acid, and 051 per cent, of lime. If this material 

 is regularly forked in either alone or with lime or artificial manures, 

 excellent results will be obtained. The artificial manure required 

 will largely depend upon the physical and chemical properties of the 

 soil, but the figures showing the composition of various parts of the 

 Para rubber plant will indicate, in a general way, the ingredients 

 required. Potash and nitrogen are very abundant in the fresh 

 and fallen leaves and lime is abundant in the woody structures. 

 Manuring Old and Young Trees. 



The method to be adopted in manuring this product is determined 

 by the age of the trees and the kind of manure used. 



Where very soluble manures such as sodium and potassium 

 nitrate, ammonium sulphate, potassium chloride or sulphate, and 

 similar compounds are used, they should be mixed with dry earth and 

 broadcasted over the area where the young rootlets are actively grow- 

 ing. If such manures are applied to areas which do not possess 

 rootlets, the greater part will probably be carried away during the 

 first few rainy days. After the manures have been applied the land 

 should be forked to a depth of four to six inches. 



