122 BULLETIN NO. 139 



cent. The soil was all made up to the same percentage mois- 

 ture, and water added through the tube in the bottom twice a 

 week to keep the weight constant. Thus, there was a constant 

 flow of water from the bottom to the surface. 



TABLE 2. SOLUBLE SALTS IN VARIOUS DEPTHS AFTER 

 WATER HAD EVAPORATED FROM 3OIL FOR THIRTY- 

 SEVEN DAYS. THE SOILS BEING KEPT MOIST FROM 

 BELOW. 



Parts Per Million of the Dry Soil. 



Greenville Soil and Following Amounts of NaCl. 



<u 



bo 



<L> v - g 



CX C o^ ^> ^>. ^. ^x ^> ^ ^x <u 



V O if) * 



Q\y- r-H CN CO TT ^-O ^O rx ^-H 



^ < 



1 1,730 17,408 30,082 75,223 100,241 233,875 216,886 217,045 273,794 129,587 



The experiment was carried on thirty-seven days, after 

 which the soil was removed in inch sections and the total soluble 

 salts determined in each sample by the method already de- 

 scribed. The results are given in Table 2. 



In all of the cans there was a decided upward movement 

 of salts and an accumulation at the surface. This was especially 

 pronounced in the soils containing a large amount of salt. There 

 was a greater difference between the surface inch and the one 

 next to it than between any other two. This was due to crys- 

 tallization of salt at the surface. The t experiment shows that 

 salts move readily upward witri the water current and illustrate 

 the method of alkali accumulation on the surface of irrigated 

 lands. 



4. Leaching of Soils. 



Five glass percolators of the Oldberg type were filled with 

 Greenville loam and arranged on a rack, one above another in 

 such a way that water dripping from the top one percolated into 

 the one below and so on to the bottom. Above the top perco- 



