A FORTNIGHTLY REVIEW 



OF THE BOTA; 



IMPERIAL DEPARTMENT OF AGRICULTURE FOR THE WEST INDIES. '^ 



Vol. XV. No. 381. 



BARBADOS, DECEMBER 2, 1916. 



Price Id, 



CONTENTS. 



Soil, 



Bacteria in the 



Enemies of' . 



Book Shelf 



California Orange Groves, 



Improvement of 



Cotton:— 



Changes in Cotton Seed 

 During Storage 



Cotton Exports from the 

 West Indies 



Sea Island Cotton Mar- 

 ket 



Department News 



Department Publications 



Gleanings 



Grenada, Agricultural 



Cadetships in 



Grenada, Progress of Land 



Settlement in 



Items of Local Interest ... 



Market Reports 



Manchester and the West 



Indian Cotton Confer- 

 ence 



Notes and Comments ... 

 Philippines, Testing of Oil 



Bearing Nuts in The ... 

 Root Systems and Leaf- 

 Areas of Corn and the 

 Sorghums 



Page, 



The 



Page. 



.. 391 



S99 



.S97 



394 



390 



390 



390 

 399 

 393 

 396 



395 { 

 I 

 397 

 398 

 400 



393 1 

 .392 i 



394 



394 



Silk Camp, A 



Soil Ventilation, Construc- 

 tive 385, 392 



Sjiiuige Cultivation in the 

 Bahamas, Improvemelit 



of 392 



Sudan Grass and Johnson 

 (Jrass, Distinguishing 

 Characters of Seeds 

 of 395 



Sugar: — 



The Colouring Matter of 

 Cane Juice.s 389 



The Study of the Sugar- 

 cane in India 388 



The Sugar Crop in 

 Porto Rico and Santo 

 Domingo 389 



Weather: — 



Crop Conditions in Bar- 

 bados 387 



Hea\'y Rainfall in the 

 West Indies ... .. 387 



Hurricane Damage in 

 Dominica .387 



West, Indian Exhibit at 

 tlie Canadian Natiimal 

 Exhibition 392 



Constructive Soil Ventilation. 



"hen considering the composition and struc- 

 Jtiire of a fertile soil we are very apt to 

 ) overlook the fact that air is a constituent 

 part just as essential as vcater or plant nutrients. Air 

 supply has never taken definite shape in soil science 

 to the extent water-supply '<r plant-food supply has, 

 and consequently, an important field of investigation 

 appears to lie practically untouched. It is true that 

 drainage in relation to soil ventilation is appreciated 

 as well as methods of cultivation that go to produce 



a good tilth, but that does not teach us anything: it 

 gives us no definite clue as to what the roots of 

 different crops require, or whether air supply might 

 not be more scientifically adjusted to suit the roots of 

 different crops and the beneficial bacteria that function 

 under similar conditions in the soil. If under certain 

 circumstances it were found to be desirable, it should 

 be quite practicable to supply the soil with air by more 

 direct means than by cultivation or drainage, just as 

 we know it is practicable to supply the soil with plant 

 food in the form of chemicals instead of relying upon 

 weathering and the decay of organic matter. These 

 considerations suggest a new aspect of land culture, 

 namely, Constructive Soil Ventilation — a definite 

 branch of agricultural engineering associated with 

 Drainage. 



Before proceeding to enlarge upon this idea, it 

 will be well to consider what evidence exists to 

 justify it. 



The importance oi soil ventilation has been 

 brought out prominently by the observations of 

 Howard in India. He has pointed out that crops 

 undoubtedl}' differ greatly in the amount of air their 

 roots require. In India, for example. Gram requires 

 a great deal of air, and only a moderate amount of 

 water. In some parts of the country the conditions 

 both natural and artificial are such that the roots get 

 plent)' of air. Here this particular crop thrives. But 

 in other places where, for instance, irrigation conditions 

 obtain, Gram will not grow successfully. Howard 

 maintains that the proper provision of air to the soil 

 is all that is necessary for extending the cultivation of 

 this useful crop. The facts are the same in regard 



See Bulletins Nos. 52 and 61, Agricultural Research Insti- 

 tute, Pusa; also Agricultural Senis, Vol, XIV, No. 352, p. 337, 



