Oils and Fats. 



[July, 1912. 



vided they continue to make satisfactory- 

 growth with good leaf-development, do 

 not require manure, but trees that are 

 backward or growing in poor soils 

 should be manured as soon as the first 

 blossoming period arrives. By manur- 

 ing and cultivating the soil, the back- 

 ward trees may be brought to a state of 

 development uniform with that of the 

 most vigorous trees on the estate. A 

 suitable manure for this purpose consists 

 of castor-cake 4 lb., steamed bones 2 lb,, 

 bone-meal 2 lb,, kainit 3 lb., chloride of 

 potash 1 lb, mixed with about 24 lb, pf 

 cattle manure, for each tree. This com- 

 post should be lightly forked into the 

 soil t near the growing tips of the roots, 

 which will be found at a distance from 

 the base of the trunk varying according 

 to the soil and the age and vigour of the 

 specimen treated. After one or two 

 crops of nuts have been removed from 

 the trees, the whole plantation should be 

 manured, and this treatment should be 

 continued every two years, a portion of 

 the estate being treated annually. Dr. 

 Bachofen has stated (Revue des Cultures 

 Coloniales, 1900, 6, 75) that a crop of 1000 

 nuts of average size removes the follow- 

 ing constituents from the soil : Nitrogen 

 8'6 lb., phosphoric acid 2'4 lb., potash 18'7 

 lb., lime 2-3 lb., and salt 214 lb. An 

 annual yield of from 5,000 to 6,000 nuts 

 per acre is commonly produced by trees 

 in full bearing, and it theiefore be- 

 comes evident that if the soil is not to be 

 impoverished, manuring must be prac- 

 tised to replace the constituents that are 



removed. Nitrogen is commonly sup- 

 plied to the soil of coconut plantations 

 in the form of cattle-manure. In cases 

 where grasses have been allowed to grow 

 beneath the coconut trees the usual 

 practice is to tether animals to the trees 

 to graze so that their urine and drop- 

 pings may enrich the soil. Native culti- 

 vators seldom manure their trees inten- 

 tionally, but as the palms are usually 

 grown in close proximity to villages or 

 native dwellings the soil is enriched by 

 deposition of household sewage and 

 organic refuse of all kinds. Fish manure, 

 bones and bone-meal, and castor-cake 

 are the manures usually employed, in 

 addition to cattle manure. An easy 

 method of restoring nitrogen to the soil 

 is by the practice of " green-manuring." 

 For this purpose leguminous crops, 

 which, with the aid of bacteria, are able 

 to fix atmospheric nitrogen, are grown 

 between the lines, and are ploughed into 

 the soil whilst they are still green. 

 Plants found suitable for this purpose 

 are the pigeon pea (Cajanus indicus), 

 the velvet bean (Mucuna spp.), the sensi- 

 tive plant (Mimosa pudica), the ground 

 nut (Arachis hypogcea), Vigna Catiang, 

 sunn hemp (Crotalaria striata) and Teph- 

 rosia striata (cf. this Bulletin, 1906. 

 4, 118). 



The following table taken from the Cir- 

 culars and Agricultural Journal, Royal 

 Botanic Gardens, Ceylon (1911, 5, 2b0), 

 gives the percentage composition of the 

 green parts of several of the more impor- 

 tant plants found suitable for use a8 



green manures. 

 Sun'dried Sam-pies of Leguminous Plants. 



Vigna Crotalaria Crotalaria 



Ash 



Lime 



Potash 



Phosphoric acid 

 Nitrogen 



Ash 



Lime 



Potash 



Phosphoric ftCid 

 Nitrogen ,.. 



Catiang. 

 1416 

 3-40 

 3-45 

 0-83 

 3;88 



Leucama 

 glauca. 



striata. 

 6'62 

 T05 

 2'35 

 0-77 

 3-80 



T ephrosia 

 purpurea. 



juncea. 

 9-62 



1- 20 



2- 43 

 1-54 



3- 75 



Tephrosia 

 Hookeriana. 



Phaseolus 

 lunatus. 



7 70 



1'72 



2'70 



0-72 



2'98 



Tephrosia 

 Candida. 





5'52 



4'89 



4-42 



516 





1-82 



1-46 



I'M) 



1-03 





1*38 



1-17 



1-27 



1'63 





0-31 



0-56 



0-44 



0-37 





S'57 



339 



m 



m 



