[shutt-burwash] 



ALKALI IN CLAY SOILS 



63 



With respect to the zones "C'and "D" (1'.5 — 5'.0) the results are 

 somewhat erratic, showing considerable fluctuation from year to year. 

 No marked diminution occurred in "C" (1'.5 — 3'.0) in 1917 butin "D" 

 (3'.0 — 5'.0) there was a reduction of 2% in the total saline matter. 

 In 1918 the saline content of both "C" and "D" was very materially 

 lower. In 1919, and to a still greater degree in 1920, the results indicate 

 an increase in the concentration of saline matter in both "C" and "D", 

 though in"C" it did not reach the percentage present in 1916. It is very 

 doubtful if these movements are to be attributed to irrigation, for 

 field notes made on an examination immediately following an irrigation 

 indicate that the water had not penetrated below 1'.5. 



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



Air-dried Soil. 



Crops— 191Q, Clover: 1917, Alfalfa: 1918, Wheat and Alfalfa: 1919, Pasture: 

 1920, Barley, Clover and Alfalfa. 



