418 



EXPERIMENT STATION EECOED. 



[Vol. 38 



Finally, it is concluded that " soluble salts ... do not long remain localized, 

 as reported by earlier investigators. Moreover, the rate of movement is 

 affected by the water content of the soil and the mass of salt present. Where 

 moisture is being lost by evaporation, the upward movement is more rapid 

 than the downward translocation in heavier soils ; but in case of sands the 

 downward translocation is indeed slight, thus indicating that soluble salts, 

 such as sodium nitrate, are more likely to be lost by upward movement to the 

 surface of sandy soils during a drought than in case of heavier soils. . . . 



" The indications are that the translocation of soluble salts in soils is brought 

 about by means of diffusion, by reactions that take place in the soil, and by 

 moisture movements. Field and laboratory experiments in progress should 

 throw additional light upon moisture movement in different soil classes, as 

 well as the upward movement from the subsoil of substances in solution." 



Excess soluble salts in humid soils, S. D. Conner {Jour. Amer. Soc. Agron., 

 9 (1917), No. 6, pp. 297-301). — Experiments conducted at the Indiana Experi- 

 ment Station are reported, the results of which are taken to indicate that 

 " black soils in humid regions sometimes contain excessive amounts of soluble 

 salts. These soluble salts may cause injury to crops, due to high concentration 

 of nontoxic salts, to a lower concentration of more toxic substances, or to a 

 combination of both. The salts occurring in liigh concentration are generally 

 nitrates. The toxic salts occur generally in acid soils and are mainly soluble 

 salts of aluminum. The only clay and loam soils that were found to contain 

 excessive soluble salts were of artificial origin, such as spots where old stables 

 had stood." 



Lysimeter investigations, H. K. Dean (U. S. Dept. Agr., Bur. Plant Indust., 

 Work Umatilla Expt. Farm, 1915-16, pp. 14-16). — Loss of moisture from cropped 

 and uncropped sandy soils of the Umatilla project in Oregon in 1915 (May 22 

 to the end of the year) and 1916, through percolation and evaporation and 

 transpiration, as determined with concrete lysimeters 3.3 ft. square by 6 ft. 

 deep, was as follows : 



Percolation and evaporation and transpiration (in acre-inches) from lysimeters. 



During 1916 both the irrigation water and the percolate were tested and 

 found to contain calcium, carbonates, bicarbonates, chlorin, sulphates, and 

 nitrates. Less of the bicarbonates, chlorids, and sulphates and more calcium, 

 carbonates, and nitrates were found in the percolate than were added in the 

 irrigation water. The greatest amount of nitrates was obtained from the 

 lysimeter growing soy beans and vetch, with the uncropped lysimeter second. 

 Comparatively little nitrate was lost from the lysimeters with alfalfa. 



