Volume VIII SEPTEMBER, 1916 Part 1 



UAKUfcN. 



THE AMMONIACAL NITROGEN OF PEATS 

 AND HUMUS SOILS. 



By J. C. B. ELLIS, B.A., and C. G. T. MORISON, M.A. hotap(ICAI. 



{School of Rural Economy, Oxford.) 



The detailed examination of humus soils of various kinds is becoming 

 of increasing importance in view of the schemes now on foot for the 

 reclamation of much heath and moor land. One of the most important 

 things to establish has seemed to the authors to be the amount of nitrogen 

 existing in the form of ammonia or of ammonium compounds, as it is 

 possible that a knowledge of this figure might form a basis for a more 

 scientific classification of soil organic matter than at present exists. 



In those humus soils where so-called acid conditions obtain it might 

 be expected that the amount of ammoniacal nitrogen would be high, 

 as in these cases it would have the maximum opportunity for accumu- 

 lation. Consequently the preliminary work was carried out with soils 

 of this kind; mostly so-called acid peats.' 



It had previously been noticed by one of us that the method adopted 

 by Russell^ for the determination of ammonia in arable soils seemed to 

 give concordant results when applied to humus soils. The method 

 consists essentially in the distillation of an adequate amount of the 

 peat with magnesia at a temperature of 40° under as low a pressure 

 as can be obtained with an ordinary water pump. 



It was decided to employ magnesia as the base for the liberation 

 of ammonia, because the manipulation is easier, and because from 

 Russell's results and from the results of our preliminary experiments 

 there seemed no reason to doubt but that the magnesia was attacking a 

 definite group of substances in the peat. 



^ Morison and Sothers, This Journal, vol. 6, pt. i, p. 88. 

 Journ. of Agiic. Sci viii 1 



