4 REPORT OF THE AGRICULTURAL RESEARCH 



the chief means by which the fertility on the farm is main- 

 tained against heavy and continuous cropping. 



A new and important feature in the experimental work 

 on the farm is a series of plots in which the biological factor 

 connected with the use of green manuring as well as other 

 bacteriological problems will be studied by the Imperial 

 Agricultural Bacteriologist in conjunction with the Im- 

 perial Agriculturist. Too much stress cannot be laid on 

 this work, which is now generally recognised as affording 

 a most promising field for research into the principles 

 underlying the fertility of soils. 



4. Chemistry. — The work on the availability of plant 

 food in soils and that of the moisture requirements of crops 

 to which reference has been made in previous reports is 

 being continued. The examination of water after passing 

 through certain depths of soil continues to be carried out. 

 It has been observed that not only is there less nitrate in 

 the drainage water from the cropped soil than from fallow- 

 land, but the deficiency could not be accounted for merely 

 by assimilation by the crop. Dr. Leather, therefore, 

 deduces that either less nitrate was formed in the presence 

 of the crop or some other agent than the crop was assimilat- 

 ing the nitrate. The investigations in Usar soil which 

 have been going on for some years have so far not led to any 

 very useful nor definite results. 



In the last Annual Report mention w^as made of the 

 investigation into the date-palm sugar-industry which 

 was carried on by Mr. Annett, the Supernumerary Agri- 

 cultural Chemist. This has been continued during the past 

 year and has led to an accumulation of very valuable in- 

 formation on the subject, which is now in the press and 

 will soon appear as one of the Memoirs of this Department. 

 Besides recording the history of this industry Mr. Annett 

 gives a good description of the cultivation and tapping of 

 the palm and the manufacture of the raw and refined sugar. 

 He found that the juice contains 8 to 10 per cent, of sucrose, 

 associated with practically no glucose. This fact indicates 

 that it is an exceedingly good materials for the production 



