JAMAICA. 



B U L L E T O 



OF THE 



BOTANICAL DEPARTMENT. 



Vol. VII. 



New Series.] AUGUST, 1900, 



^ Part VIII. 



WATER IN SOME OF ITS RELATIONS TO AGRI- 

 CULTURE. 



By W. E. BuTTENSHAw,^ M.A, B Sc 



Government Lecturer in Agricultural Science, Jamaica. 



Every person in any way connected with A agriculture will readily 

 admit the importance of the subject of this article. The subject of 

 the water supply intrudes itself forcibly enough upon the English 

 farmer, but the planter in tropical countries has to give it far more 

 serioas consideration. The former has to busy himself more often with 

 getting rid of superfluous water i.e., drainage, than with the difficulties 

 of getting sufficient water for the needs of his farm. On the other 

 hand in many parts of the tropics, agriculture would be absolutely 

 impossible without an artificial water supply. But this article is not 

 concerned solely with irrigation ; it is intended to be rather a general 

 survey of the various ways in which water is connected with the pro- 

 duction of crops. 



The fact that many plants are found on analysis to contain as much, 

 as 90 per cent, of moisture at once suggests some of these connections 

 it will be as well to enquire first, what is the duty of this large propor- 

 tion of water ? Secondly, how does the plant obtain it ? and thirdly, 

 kow can the agriculturist help the plant to obtain its water supply ? 



Although it seems natural that the subject should be presented in 

 this succession, that is, that the consideration of the demand and the 

 reasons for it should precede that of the mode of supplying it, it will 

 perhaps be found convenient for the purposes of this article to discuss 

 first the supply and then the way in which this supply is utilised. We 

 ihall then first take up the subject of the water in the soil, how it is 

 ohtained and how preserved, devoting the second part of the article to 

 the relation of the plant to water. 



1. Welter in the toil. There are two questions to be considered : — 

 1st how does the soil get its moisture, and secondly, how can this soil 

 moisture be conserved. 



Of the natural method of water supply little need be said, for it is 

 not much that the agriculturist can do to increase or diminish the 

 rainfall. It is however in the choosing of a plantation that that 

 subject must receive close and careful consideration. 



Although it has been said that the agriculturist can do little to in- 

 crease the rainfall, he has considerably more power in his hands than 



