8 SOILS OF THE SUTTER BASIN. 



In the earlier report, however, note is made of the occasional oc- 

 currence of soil areas along the western side of the area of Sacra- 

 mento clay and lying between Cranmore and Knights Landing in 

 which the average amount of total alkali salts present in the dry soil 

 to the depth of 6 feet is less than 200 parts per 100,000 (an amount 

 ordinarily considered harmless), but in which the bulk of the salts 

 have become concentrated in the immediate surface. Under such 

 conditions the surface concentration may prove sufficient to prevent 

 development of seedling or shallow-rooted plants, and the earlier 

 report expresses some apprehension of difficulty in bringing such 

 areas under successful cultivation. 



A rather extensive area is indicated upon the alkali map accom- 

 panying the earlier report, lying near the southern lower-lying por- 

 tion of the Sutter Basin, in which the average salt content is some- 

 what greater than that previously stated and sufficient to cause 

 injury to the more sensitive crops, but in which the salts are more 

 uniformly distributed throughout the soil profile. 



Assuming that means be provided of effectively removing surface 

 waters and of permanently maintaining the level of the water table 

 at a desirable depth, it is believed the removal of a portion of the 

 salts in the drainage waters and a wider distribution and conse- 

 quent dilution of the remaining salts throughout the soil column 

 would soon take place. Under such conditions as stated the alkali 

 problem would not constitute a serious consideration. 



OCCURRENCE OF SEEPAGE WATERS. 



In the report of the earlier survey it is suggested, as previously 

 noted, that some difficulty might be anticipated in maintaining a 

 favorable position of the water table, owing to seepage through the 

 levees. 



In this report it is assumed that that matter will be taken care of 

 by the engineers who provide for draining the area. In the 15 

 or 90 reclaimed tracts along the Sacramento River covered by similar 

 soils, and visited during the progress of the later investigations, this 

 anticipated difficulty had not been realized to any degree prohibitive 

 of utilization of the land for agricultural purposes. In one case 

 il was observed that the great weight of the material forming the 

 Levee had compressed considerably the soil on which it was lying 

 and had apparently rendered it more compact and less pervious. It 

 was further noted that water over the Sacramento clay does not 

 appear to move laterally through the soil with ease, except where 

 there is a stratum of material of light texture in the subsoil. 



[Cir. 79.] 



