124 BULLETIN NO. 139 



TABLE 3. SOLUBLE SALTS IN SUCCESSIVE LEACHINGS OF 

 3 LITERS EACH FROM PERCOLATORS. 



The method used in extracting the soil was the same as already 

 explained. The results are given in Table 4, which shows a 

 great uniformity in the soils of the different percolators. 



TABLE 4 SOLUBLE SALTS REMAINING IN SOILS CONTAINED 

 IN PERCOLATORS AFTER BEING LEACHED THREE 

 MONTHS AND ALLOWED TO STAND SIX MONTHS. 



No. of Percolator Total Soluble Nitrates in p. p. m.. 

 From Top Salts in p. p. m. Nitric Nitrogen 



5. Conclusions. 



1. The accumulation of alkali salts in soils which were 

 previously fertile has necessitated the abandonment of a great 

 deal of land in the irrigated portion of arid America. 



2. Experiments reported in this publication show that salts 

 are transferred through the soil very readily by moving water. 



3. It is probable that low lands will continue to be ruined 

 by the accumulation of alkali salts as long as the uplands are 

 over irrigated. 



