^fcVk 

 BOIA 

 OAK 



A FORTNIGHTLY REVIEW 



OF THK 



IMPERIAL DEPARTMENT OF AGRICULTURE FOR THE WEST INDIES. 



Vol. X. No. 242. 



BARBADOS, AUGUST 5, 1911. 



Price Id. 



CONTENTS. 



Page. 



Agricultural Trainiuij in 



Uoiuinica 248 



Agriculture in .laiii/iica, 



1909-10 2.55 



Agriculture in Porto Rico 



in 1910 247 



Alcohol for Motive Power 249 

 Bacteria in the .Soil. Work 



of 249 



Page. 



Nitrogen, Loss and Gain 



in Cultivated Soils ... 249 



Notes and Comments ... 



I'russic Acid, Formation 

 duriiigGermination ... 



Rulilier and Gutta-Perclia 

 in Borneo 



Rvd/oer in Togoland and 



German East Africa 248 



Rubber, Tackiness in ... 251 



Southern Nigeria, Agricul- 

 ture in 



Students' Corner 



Sugar Industry : — 



Changes in Sugar Solu- 

 tions at High Temper 



atures 



The Sugar Industry of 

 the United Stjites, in 

 1909 



Supply of Sulphur to Cul- 

 tivated Crops 



Te)iluosi.i Candida and 

 T. Purpurea as Green 

 Dressing Crops in 

 St. Lucia 



West Indian Products ... 



248 

 249 

 253 



251 

 253 



.. 243 



243 

 241 



245 



2r.5 



The Supply of Sulphur to 

 Cultivated Crops, 



*HE e.xtunt to which culli\atc-d plants require 

 nitrogen, phosphate and potash, in order that 

 ^they may attain a proper development and 

 give an adequate yield, has long been the subject of 

 practical determinations, by agriculturists, in the form 

 of laboratory and field experiments. There has not 

 been by any means the same amount of attention to 



the similar requirements in regard to sulphur as a plant 

 food; for various circumstances, to be stated later, have 

 led it to be considered that these are small and ade- 

 quately supplied without the making of any specific 

 attempts to provide suljihur in manures. Recent work* 

 on the part of investigators has, however, made it doubt- 

 ful if this is a correct view of the case, and the purpose 

 of the following article is to present a simple account 

 of the objects and results of this work. 



The investigation was suggested by experiments 

 which had for their object the determination of the 

 amount of sulphur in the feeding material given to 

 sheep for the production of wool. Sheep's wool consists 

 largely of a proteid material rich in sulphur, and this 

 made it appear that the crops on which the sheep 

 were usually fed must contain and provide a larger 

 amount of that element than is commonly understood. 

 The subject was further advanced by the recognition 

 of the fact that the determination of the amount of 

 sulphur in plants, by an e.xamination of the ash, gives 

 results which are generally much too low, as that sub- 

 stance is lost to a greater or less extent during the 

 course of the analyses; the work of several investi- 

 gators has given support to this view of the case. 



In the trials which were undertaken, methods 

 were employed for the determination of the amount of 

 sulphur present (as sulphur trioxide) which would 

 entail as small a loss as possible of sulphur during 

 the work of analj^sis. Some of the results obtained 

 in this way are interesting. They show that a given 

 quantity of rice grain contains one hundred times 

 as much sul[)hur trioxide as that which would be 

 indicated by analysis of the ash from that amount 



*I!esearch Bulletin No. 14, of the Wisconsin University 

 Agricultural Experiment Station, entitled SnJ^thiir HequiremenU 

 vf Funn Ciops in Ileliiiiun tu the i^oil mtil Ah S^ipply. 



