[shutt] 



ALKALI IN CLAY SOILS 



231 



Plot II. — Water soluble Saline Content Expressed in Percentages on Air- 

 Dried Soil. 



Crops.— 1916, Clover: 1917, Alfalfa: 1918, Wheat and Alfalfa: 1919, Pasture: 

 1920, Barley, Clover and Alfalfa: 1921, Volunteer Barley. 



TABLE III. 



that an area of heavy clay may be safely irrigated for a number of 

 years, provided that the irrigation be judicious, say, approximately 

 13^ feet annually and that at the outset the surface soil to a depth 

 of 1' 6" is free from alkali, and further, that provision is made for the 

 removal of surplus water by surface drains and ditches. 



Note. — Mechanical analyses of soils from both plots were made by Mr. John 

 M. Macoun. 



