



A FORTNIGHTLY REVIEW 



OF THK 



IMPERIAL DEPARTMENT OF AGRICULTURE FOR THE WEST INDIES. 



NEW 



botat 



Vol. XI. No. 266. 



BARBADOS, JULY 6, 1912. 



Pbiob Id. 



CONTENTS. 



^sericulture in St. Lucia, 

 1910 .. 



Bay < 111, Supply (if 



Cliick, Development i>f 

 Embryo 



Cotton Notes :— 



Annual Report of the 

 British Cotton Grow- 

 ing Association, liUl 

 West Indian Cotton ... 



Department News 



Dominica Grammar School 

 Agricultural Science 

 at 



Expoit-i from Barbados, 

 1911 



Fungus Notes : — • 



Exanthema and Sipia- 

 mosis of Citrus 



Pack. 



219 

 217 



213 



Page. 



... 220 



... 218 



Gleanings 



Insect Notes : — 



Entomology in Fiji 



Mango, Enibryony of the 212 

 Manure. New Artificial... 216 

 Market Reports 224 



Nitrates in Cultivated 



Iheories Concerning Soil Fertility. 

 I. 



'N recent years, great changes have taken 

 place with respect to the way in which the 



j.soil is regarded in relation to the nutrition 

 of plants, and investigators are by no means agreed in 

 their views on the subject. The most general opinion 

 is that the soil contains definite food bodies which are 

 taken up by the plant, for its nutrition, and that owing 

 partly to weathering and partly to the action of micro- 

 organisms, among which bacteria are very important, 

 some of these, as well as other substances, are produced 

 or destroyed, according to the conditions that obtain. 



Other hyphotheses exist, however, among which the most 

 divergent from what has been stated is that of Whitney, 

 Cameron and other.s, who have been engaged in work 

 for the Bureau of Soils of the United States Depart- 

 ment uf Agriculture. It is the present purpose to 

 review this hypothesis, under the guidance of what is 

 known broadly concerning the nutrition of plants and 

 their relationship to the soil in which they grow; and 

 as this has been done ably and at length in a recent 

 article by E. J. Russell*, what is said thfre will be 

 used freely as a guide in dealing with the matter. 



Before the special aspect of the subject receives 

 attention, it will oe useful to give a brief account of 

 the main circumstances in the relationship b'^tweea 

 the soil and plant. In an article published some 

 time ago in the Agricultural News,f a review was 

 given, at some length, of the things that are essential 

 for plants to grow properly, and stress was laid upon the 

 fiict that insutticiency in regard to the provision 

 of any one of these essentials results in a decreased 

 power of the plant to make use of all the others. 

 The necessary conditions were stated to be, in the 

 order of immediate urgency: (I) a supply of water; 

 (2) a certain range of temperature; (3) a .supjily of 

 mineral salts: (4) the presence of certain kinds of light; 

 (.5) air containing oxygen and carbon dioxide. For 

 a statement of the ways in which these are necessary, 

 reference i.s made to the article quoted; the important 

 matter is that they are necessary, and that they must 

 all be present in sufficient amount in order that plants 

 may make the best use of them. 



* The Soil and the Plant, by E. J. Russell, D.Sc ; Science 

 Pioyiess, Vol. VI, No. 21, p. 135. 

 t Vol. ]X, p. 257. 



