64 THE ROYAL SOCIETY OF CANADA 



Plot II. — The saline content of the zone O'.O — I'.S (A and B) is 

 fairly constant throughout the period of investigation with the 

 exception of that for the season 1917. The evidence at the conclusion 

 of five years' irrigation is quite favourable indicating as in Plot I that 

 there has been no appreciable increase of alkali in the soil to a depth 

 of 1'.5. The reason for the comparatively high alkali content of 1917 

 is not apparent; it may be the result of a rise of alkali following 

 irrigation but more probably may be explained by a slight error in 

 locating the point of collection. 



The alkaH content of the zones "C" and "D" varies considerably 

 from season to season; there is no general trend. It is impossible to 

 advance any satisfactory reason to account for these results; they 

 may be due to a number of factors. Our impression is that the 

 several determinations represent original impregnations and that the 

 apparent fluctuations are not the result of the movement of soil 

 moisture. 



As publication in the proceedings of the Society this year necessi- 

 tates the presentation of material in the briefest form possible the 

 detailed field notes are omitted. It may, however, be stated that 

 each plot received three irrigations during the season and that at no 

 tim.e during the whole five years of the investigation was there any 

 surface indications of alkali. 



Throughout the whole period of observation the crops on both 

 plots were fair to good, with the exception of that on Plot II in 1917 

 which showed signs of distress evidently from alkali. At the con- 

 clusion of this work, and after six years' irrigation, the crops of 

 the season 1920 were found to be excellent, with no signs of 

 injury from alkali. These observations confirm what has been shown 

 by the analytical work, that irrigation, under the conditions of the 

 experiment, had not caused any appreciable rise of alkali. Notwith- 

 standing a close almost impervious subsoil strongly impregnated with 

 alkali, it would seem possible that an area of heavy clay may be safely 

 irrigated for a number of years, provided that at the outset the surface 

 soil is free from alkali and that provision is made for the removal of 

 surplus water by surface drains and ditches. 



