

■?fe 









A FORTNIGHTLY REVIEW 



OF THE 



IMPERIAL DEPARTMENT OF AGRICULTURE FOR THE WEST INDIES. 



Lisa. 

 HEW\ 



<iAI<0/ 



Vol. XL No. 253. 



BARBADOS. .JANUARY 6, 1912. 



Pkicb Id 



CONTENTS. 



Pack. 



Paob. 



Anthrax Serum fur 11 u- 



iiian Aiithriix 13 



Aromatic Gra.ss Oils 4 



Bananas and Cotfee in 



Costa Rica 4 



Caiiiliodia Cottun in Madras 



Uainphor, Cultivation of ... 5 



Canii.lior in FnrinMs;i. 191CJ !) 



Cotton Notes : — 



Cotton Cultivation in 



Southern Siaiii 6 



Egyptian Cotton Crop ... 6. 

 West Indian Cotton ... 6| 



Fungus Notes : — \ 



Experiments on the Con- 

 trol of Leaf Rust of j 

 Ground Nuts 14 1 



Fustic Wood, Sub-stitutes 

 and Adulterants for ... 7 



Gleanings 12 



Gold Coast, Nortliern Ter- 

 ritories, Trade and 

 Agriculture of 8 



Hooker, Sir .lo.seph Dalton, 



t).M.. the Late 5 



Insect Notes : — 



Summary of Information 

 Given during 1911 ... 10 



Internation.il Ruliber and 

 Allied Trades Exposi- 

 tion. Third J3 



Lyon Bean in St. Lucia, 



Trialof 4 



Marktt Reports 16 



Notes and Comments ... 8 

 Papaw Plant, Flowers of 9 



Poultry Notes; — 



Till- Fattening of poultry U 

 Prickly Tear in Making 



Whitewash, Use of ... 8 



Seaweed as Manure 3 



Seychelles, Exports from, 



1910 14 



Soil Moisture, Lower Limit 



of Available 9 



Soils, Colour of 1 



Students' Corner — 

 Agricultural Examina- 

 tion Results 13 



Sugar from Shreddt-d C;ini' 3 

 Sugar Imjiorts into the 



I'nited States 3 



West Indian Products' ... 1.5 

 Wihl Ruliber in the Congo 11 



The Colour of Soils, 



pHE practical importance of the colour of 

 [soils otises from the circumstances that it 

 ^possesses an inHuenee as regards the amount 

 of absorption of the energy of the sun, and often that it 

 serves as a guide to the condition of th? soil with refer- 

 ence to drainage, to the kind of crops that may be raised 

 in the soil, and to the proper method of cultivation. 

 These matters are given attention in Bulletin No 79 

 of the Bureau of Soils, of the T'nited States l^ep.-xrt- 



ment uf Agriculture, and much of the information in 

 this is employed in the following article. 



It is important to realize at the outset that the 

 colours of soils are not pure colours; they may be best 

 described as shades or tints. This arises chiefly from 

 the fact that the material which is responsible most 

 usualh' for the colour o( soils is ferric o.xide, a compound 

 which varies itself in colour, and, in the soil, is tinted 

 on account of the presence of other materials. Many 

 colours are found in soils, but it is possible to select 

 a few that aro characteristic; in relation to their origin, 

 they are dependent primarily upon the relative propor- 

 tions present of white mineral, and organic, matter, and 

 of ferric oxide. A convenient classificaiion has for its 

 main features white, black, and red. with greyish bet- 

 ween the first two, brownish between the two last, and 

 yellowish between the red and white. In a general waj^ 

 whitish or grey soils are not of much agricultural value; 

 in wet climates they are generally wanting in organic 

 matter. Soils may also be white from an accumulation 

 of alkali, and from their containing a high proportion 

 of.gypsuiu. 



It is well recognized that yellowish soils are very 

 common, and it is general!}' considered that their colour 

 is due to the presence of small amounts of ferric oxide, 

 more or less combined with water, or ' h^drated', as it 

 is usually expressed. Wherever agriculture is carried 

 on, black soils are held in high estimation. They often 

 contain a high percentage of lime, and their colour is 

 considered to be due to the formation of black humus 

 compounds through action between the organic bodies 

 and the lime present iii them; such soils are commoni 

 over calcareous rocks, in the West Indies. As regards 

 the colour of sandstone and of ordinary soils, the usual 

 opinion is that this is due to a film of coloured oxides. 



