FORTNIGHTLY REVIEW 



OF THE 



IMPERIAL DEPARTMENT OF AGRICULTURE FOR THE WEST INDIES. 



LIBRARY 



NEW YORK 



BOTANICAL 



OaRDEN. 



Vol. VIII. No. 189. 



BARBADOS, JULY U, 1909. 



Price Id. 



CONTENTS. 



Page, 

 Agricultiinil Eilucatiim in 



United States 



Bahamas. Agriculture in . . . 

 Banana.s in Nicaragua ... 

 Canadian Exhiljitions, 



Barbados at 



Copper a-s an Algicide 

 Cotton Notes ;— 

 Cotton Export from 



the Virgin Ishmds ... 

 Hybriilizing of Indian 



Cotton 



West Indian Cotton ... 



Department News 



Dominica, Rainfall in 

 Essential Oils, Distillation 



for ... 



Fibre Industry in Brazil... 

 Fish and Mosquitos 



Fruits, New 



Gleanings 



Green Dressings and Their 



Ap])lication 



Insect Notes : — 



Hymenoptera 



Jamaica. Cotton in 



235 

 233 

 22!t 



233 

 238 



230 



2.30 

 230 

 229 

 233 



232 

 235 

 231 

 232 

 236 



225 



234 

 233 



Page. 

 Lime-crushing Mills, ( >il 



Engine for 228 



Mango, Normal and All- 

 normal Seedlings of 228 



Market Report.s 240 



Notes and Connnents ... 232 



Orange Thrips 229 



Pajieriuaking Industrie.s 231 

 Philippines, Suggested 



Field Staff for 233 



Pre-cocding 229 



Rice in British Guiana... 238 

 Spfinge Fisheries in the 



I'hilippines 239 



Students' Corner 237 



Sugar Industry : — 

 New Companies in 



Jamaica 227 



Seedling Sugar-canes in 



Loui.siana 227 



Scale Insects, Spraying 



for 233 



' Trojiical Life ' Prize 



Essay 239 



West Indian Products ... 239 



Greeo Dressings and Their 

 Application. 



I. THE EFFECT OX THE lUHIED I'LAXTS. 



.x^^- HE practice of the application of green 

 dressings to soils is one which has existed 

 from the earliest times : in fact, the first 

 ^ records of any rules which have been made for the 

 _ regulation of agricultural operations show unmistak- 

 fj. ahl}- that the value of burying green plants in the soil 

 ^3 for the benefit of future crops was fully recognized 



many centuries ago. That this conclusion, reached 

 empirically though it was, is not at fault, has been 

 proved again and again by the most rigid methods of 

 modern scientific investigation. Thus a feeling of 

 security in the following of the practice has resulted 

 and, in many cases, where no account has been taken 

 of local conditions, actual serious harm has accrued 

 from it. Like all other agricultural operations, that of 

 the application of green dressings is one which is 

 governed by complex, rather than simple, considerations. 



It is evident that the results of such a method of 

 manuring, as far as subsequent crops are concerned, 

 depend on two factors : ( I ) the effect on the buried 

 plants, (2) the effect on the soil. As a matter of 

 convenience, the subject will be dealt with in relation 

 to these two factors. It is not within the scope of an 

 article like the present one to give illustrative 

 examples, so that reference is made to the chapter on 

 Green Manuring in Professor J. G. Lipman's * Bacteria 

 in Relation to Country Life, pp. 237-63, where 

 a very complete account of the practice may be found. 



That the plants used in green dressings must 

 undergo great changes before they can be of any use to 

 the crops which they are intended to benefit is a matter 

 of common knowledge. These changes take place 

 through the action of bacteria, and, owing to adverse 

 conditions, they may be delayed, or even affected in 

 such a way as to render the action of the manure 

 positively harmful. This is the case in light, as well 

 as in heavy, soils. In the first instance, the fact that 

 such soils are liable to quick drying may, in the event 

 of this taking place, so interfere with the normal 

 bacterial action as to cause the buried material, when 

 the soil becomes wet again, to lose its most valuable 



* The Maomillan Company, New York, 1908. 



