A FORTNIGHTLY REVIEW 



OF THE 



IMPERIAL DEPARTMENT OF AGRICULTURE FOR THE WEST INDIES. 



Vol. XIV. No. 352. 



BARBADOS, OCTOBEB 23, 1915. 



Price Id. 



CONTENTS. 



Page. 



Page. 



African Agriculture 35] 



Bean Industry in Si . Lucia, 

 Efforts to Establish ... 339 



i ! mges ni the Guiana 



Scholarship 349 



nuts in the Seychel- 

 les, Production and Si 

 lection of u4.'I 



i !o operative Credit M" e 

 mint in < V\ lull :'.4u 



Cotton Notes: 



British < lotton < iroy 



Association 342 



\\ est Indian Cotton ... 342 



Cycli mi- Disturbance i >f 

 August in .".4!> 



Errata 339 



Export Tax on Sugar in 

 Antigua :; 44 



I ii oi Nitrogen in 

 Indian Soils 347 



Fruit Pulp, The Maki 

 of ' ... 340 



Gleanings 348 



Insect Notes: 



Insect Pests of Lima 



Beans in St. Vincent 



Loo ists in Demerara... 



Items ol Local Interest ... 



I.i Cultivation in Brit- 

 ish i ruiana 



Market Reports 



Molasses as a Substitute 

 for Oats 



Notes and Comments ... 



Onion Growers' Associa- 

 tion, Another 



Papain: Its Preparation 

 and Digest h e Properties 



Plant Diseases: — 

 Spraying oft rround Nuts 

 for Leaf Rust 



S king the Mango 



Soil Ventilation 



Industry;- 

 Sugar Extension in t he 

 Philippines 



Vanilla Growing in the 

 Seychelles 



Vitamines in Linn- Juice 



340 

 .".47 

 350 



.".4J 



352 



345 

 344 



345 



340 



350 

 342 



339 



343 



345 



Soil Ventilation. 



I,'. ALBERT HOWARD, t'.I.K.. M.A., 

 [Imperial Economic Botanist in India, lias 

 [•recently drawn attention* to the fact that 

 the necessity for irrigation, dry farming methods and 

 water conservation has, in many places, tended to 

 obscure from the minds of soil investigators, the 

 importance of the air supply ol plant roots. Even the 

 subject of drainage, so large h connected with ai r 

 supply, has not been adequately regarded from ihi s 



* Bulletin No. Si, Agricultural Research Institute, Pusa, 

 India. 



most important aspect, and it seems that the neglect 

 referred to may be responsible for low yields, and, 

 what is perhaps less likely to be realized, for the res- 

 d distribution of certain crops. 



Constant aeration and a continuous interchange 

 of gases between the soil and the air are abso- 

 lutely necessary for plant growth. The roots of plants 

 respite: which means that thej not onbj us.- up the 

 oxygen of the soil atmosphere but as well give out 

 carbon dioxide. This gas, which in large proportions 

 acts as a poison, is also produced by the decay of 

 organic matter and as the result of the growth of 

 bacteria. Unless copious ventilation takes place, the 

 supply of oxygen will be exhausted, and at the same 

 time the soil and water max become charged with 

 carbon dioxide to such an extent that a poisonous 

 atmosphere for the roots is produced. Growth will stop 

 for two reasons. In the first place there will be no 

 air for the working cells of the roots and they will die of 

 asphyxiation. In the second place there will be direct 

 inhibition of large quantities of carbon dioxide which 

 has been shown to be a poison for roots. 



Reference is often made to water-logged soils, 

 which as everyone knows are generally unsuited for 

 plant growth. But it is not the water that does the 

 harm nearly so much as the absence of oxygen. If 

 a water-logged soil could be kepi aerated it. would 

 produce good crops. This is made evident by the fact 



that plants can be successfully grown in 'water-culture 

 where the surface of absorption is great in comparison 

 with the volume ofliquid. The ease of rice which 

 grows in swamps would appear to be conflicting. Bui 

 it has a simple explanation. Asalreadj noted in this 

 journal." 1 - Harrison in India has shown that the surface 

 film of algae and other green organisms on these soils 



t Agricultural Newt, Vol. XIV. No. 339, p. 141. 



