332 University of California Publications in Agricultural Sciences [Vol. 1 



peculiar phase of these effects under consideration would seem to 

 have particular significance in that connection. First of all, 

 these soils contain, as a general rule, sufficiently large quantities 

 of salts to be commensurate with those used in the experiments 

 reported above. Secondly, the natural rainfall, irrigation prac- 

 tices, and drainage operations often wash the salts out of the 

 top layers of soil, so that this soil would be exposed to the con- 

 ditions likely to produce the inferior physical qualities attendant 

 upon deflocculation. 



During the late winter and early spring months the writer 

 had occasion to observe the standing water in the depressions of 

 the alkali lands near Fresno, California. To all appearances the 

 underdrainage of these low areas would be practically impossible, 

 owing to the imperviousness of the soil, which upon examination 

 reveals all the characteristics of the diffused salt-treated, water- 

 washed soils. Besides, the gray appearance of the soil when dry, 

 and the striking resemblance of the supernatant liquid to that 

 above the soils in the cylinders, would certainly lead one to be- 

 lieve that even under natural conditions the washing out from 

 and the dilution of the salts in alkali soils has much m common 

 with the artificial production of similar conditions. Heretofore, 

 the depressions and the remarkable imperviousness of their soils 

 have been attributed to the presence of NaoCO^j. 



It would seem that the deflocculation effects exhibited by soils 

 when added salts are washed from them would have particular 

 bearing upon the reclamation of alkali soils by underdrainage. 

 Yet the possible application of this feature to alkali reclamation 

 seems to have been omitted from the literature dealing with this 

 subject.^® Cameron and Patten^" observed somewhat similar 

 lowering of the rate of percolation, followed, however, by an 

 increase later as the washing out of the salts progressed, Hare,''° 

 in a recent paper describing tank experiments dealing with the 

 effects of alkali salts on soils and crops, does not note any pos- 

 sible effect of the added salts on percolation through the soils 

 receiving them, but does comment on the observation that NaoSO^ 



58 Hilgard, Soils, 1911, chap. 22, and U. S. Dept. Agric, Bur. of Soils, 

 Bull. 35, 1906. 



59 Journ. Amer. Chem. Soc, vol. 28, p. 1639, 1906. 



60 New Mexico Agric. Exper. Sta., Bull. 88, 1913. 



