242 THE ROYAL SOCIETY OF CANADA 



Discussion of Results. In this irrigated district the harmful salt 

 to be contended with is carbonate of soda. 



Group 1668. Good growth. In A (O'-O — 0'-5) the impregnation 

 is -066 per cent of carbonate of soda. From the appearance of the 

 crop and these results and from analysis of corresponding samples 

 taken in 1917 from good growth in an oat field at Strathmore, we 

 might conclude that approximately -05 per cent in the first 6 inches 

 does not markedly affect growth. 



Group 1667. Poor growth. In A (O'-O — 0'- 5) the impregnation 

 is • 243 per cent in the surface soil and the crop was very scanty, 

 probably not worth cutting. It was evident that this concentration 

 was very distressing to the crop, only a small percentage of the seeds 

 having germinated. 



Group 1666. No growth. The percentage of carbonate of soda in 

 A (O'-O — 0'- 5) is -477, which is evidently much too high to permit of 

 any growth. 



This investigation, it is proposed, will be continued for a number 

 of years and it is thought advisable to postpone the detailed dis- 

 cussion of the data and the establishment of limits of tolerance for 

 the various farm crops until further evidence is obtained. It is, 

 however, very satisfactory to note that the results here presented 

 show a very fair agreement with those presented in our previous 

 paper and we may therefore conclude that this work will in time 

 afiford a valuable basis for the classification of alkali-afifected areas. 

 It will also, incidentally, furnish very useful information as to the 

 movement of alkali .on lands both heavy and light under irrigation 

 but without artificial drainage. 



