i-AX-* 



A FORTNIGHTLY REVIEW 



OF THE 



IMPERIAL DEPARTMENT OF AGRICULTURE FOR THE WEST INDIES. 



Vol. XIV. No. 341. 



r.AUBADOS, MAY 22, 1915. 



Price \d. 



CONTENTS. 



Page. 



Pagjb 



nks 



i I i mar) ... 



BookShelf 



Cacao, Fermentat ion ol 

 i i -\\ est Indies Pre- 

 ferential Trade ^gree 



m tit 



Cotton N< 1 1 

 Cotton-seed i >il in Bu b - 

 Wesl Indian ( itton 



ten I ] tej i >rts ... 

 Expoi • fr m Dominica, 



1914 



Fungus Notes: — 

 A Preliminary Note on 

 ;i Disease of Carica 



Papaya 



Diseases of Cassava in 



ii rara 



Root Diseases in Malaya 



Gleanings 



G i d 5 its, Extending 



the Market for 



L69 

 L69 

 165 

 164 



171 



L66 

 166 



17.". 



168 



174 



174 

 174 

 L72 



164 



Indian C 



Feeding and Manurial 



Value 166 



In i Notes: 



The Cotton Worm ... L66 

 The Difficulties of Plant 



Quarantine 17 (| 



and Comments ... 168 

 < taions, i lultn ation of ... 171 

 M es and Lemons, < '• real 



Britain's Supply i f ... 164 

 Ri dium, \ Cheap Form of 169 



S I for Planting, Treal 



ment nf 168 



Self burning Limestone 



in Syria 175 



■ i tits' Corner 173 



Su 1 1 di 



v . Indian Canes in 

 South Ifaic i .. 162 



The Role of Calcium t lar- 



bnnate L61 



\\ est Indian Products ... 175 



The Role of Calcium Carbonate. 



;.\ LCIUM carbonati iimi si ral or 



)chalk — is a mineral to which i h ists al 

 [the greatest importance as regards the 

 tj of the soil, h neutralizes acidity; it hastens 

 itj : it acts to son - a plant food; 



it liberates potash from insoluble silicates and il lias 

 a very decided beneficial effecl upon the physical condi- 

 tions of the soil. This substance, when strongly h i 



gives off, as most people kno > dioxide, and 



quicklime or calc i oxide i The oxide, 



which rapidly b c d Into he hydroxide in 



the preseno I mi ha a imor marked 



I on the soil than rbpnate. This effect is 



•i principally in n i stei ilizin _■ 



whereby bacterial a ivitj ■ a firsl reduced, but 

 later enormously d as the oxidi 



into the carbonate. Once in the soil, the hydroxide 

 soon undergoes this change and combines with 

 carbon dioxide and other acid radicles like niti 

 and becomes calcium carbonate again, or calcium 

 nitrate as the case ma] be. Calcium carbonate, 

 the principal calci im salt in the soil, is not readily 

 removed, though since it serves as a weak base 

 against acidity and is itself soluble in water contain- 

 ing carbon dioxide, the store of calcium carbons 

 slowly depleted: and where a soil is not naturally rich 

 in this mineral, its artificial application is generally 

 advisable particularly oi i rj ind pi it] soils. 



The importanci J calcium carbonate as evidenced 

 by these considerations based on experiments conducted 

 m temperate countries leads one to ask whether the 

 mineral is adequately employed in the Tropics. It is 

 matter of conn ledge that the majority of 



soils in the Tropics are remarkably deficient in lime, and 

 their standard ol fertilit} compares tavourably with 

 those of temperate :ountries. -Manurial experiments 

 \ nli lime in the Tropics have-not given any very -ink- 

 ing results, except that in man} cases it has been shown 

 that applications o pay. Locally this has 



been demonstrated bhe Leeward Islands and in 



British Guiana* Quite recently in the Federated 

 Malay Statesf an in res ag • big ion has been 

 conducted with a view bo nine what are the 



