■24 SCIENTIFIC REPORTS OF THE AGRICULTURAL RESEARCH 



In addition to the above work assistance has been ren- 

 dered to the following Sections : — 



(1) Indigo Research Section. A large number of 



soils taken from fields on indigo estates in 

 Bihar, United Provinces and Assam have been 

 analysed in connection with the manurial re- 

 quirements of these estates (see under Soils 

 below) especially as regards the deficiency of 

 available phosphate. 



(2) Bacteriological Section. Samples of nitrates and 



nitrate liquors were analysed and analyses 

 made of the gases evolved during fermenta- 

 tion of indigo. 



(3) Entomological Section. Samples of mulberry 



leaves, etc., were analysed. 



(4) Agricultural Section. Analyses were made of 



standing crops of cane in the various fields, 

 manures, etc. 



(5) Botanical Section. Samples of feeding stuffs and 



soils were analysed. 



Methods of analysis. Several newly proposed 

 methods of analysis have been tested during the year. The 

 method proposed by Ajon of estimating potassium volume- 

 trically by precipitating as bitartrate and subsequently 

 titrating with alkali was found to give unreliable results, 

 the error being about 2 per cent., the perchlorate method 

 as modified by Davis still remaining the most convenient 

 and most accurate method. 



The Bertrand method of estimating sugars, using per- 

 manganate has been tested and found to give results often 

 5 per cent, in error as recently stated by Davis and Daish ; 

 its use at Pusa has therefore been discontinued, Brown 

 and Morris' methods as modified by Davis and Daish being 

 introduced. 



IV. Soils and Nutritive Value of Crops. 



A systematic series of analyses is being made of the 

 soils of the indigo estates in Bihar. The results so far 



