in the use of a proper amount of irrigation water, in the adoption of careful methods 

 of cultivation, and, where necessary, in the installation of uiiderdrainage to carry 

 off the excess of seepage waters and alkali. 



It is to be regretted that the whole area which it is proposed to irrigate could not 

 have been surveyed; but the limited time which could be given to this locality by 

 reason of the lack of sufficient appropriation and the pressure for work elsewhere 

 made it impossible to accomplish more than has been done. The only safe basis 

 upon which lands can be purchased and crops and methods of cultivation selected is 

 a careful and systematic examination and survey of the soils which it is proposed to 

 irrigate. This would require about six months and an expenditure of about So, 000, 

 a sum which is not available in the appropriations for this Bureau. Such a survey 

 would give a detailed map of every section of land, and an alkali map showing the 

 condition of the soil regarding the presence of alkali salts to a depth of 6 feet or more; 

 and would be a safe basis for the purchase of land and the development of the 

 country. 



If there is any general desire for the extension of this soil-survey work it would be 

 well either to ask Congress for a special appropriation for this specific work or to 

 arrange for some State or local cooperation which would enable the survey to be 

 made in the near future. 



Respectfully, MILTON WHITNEY, 



Chief of Bureau. 



Hon. JAMES WILSON, 



Secretary of Agriculture. 



REPORT BY THOS. H. MEANS AND J. GARNETT HOLMES. 



AREA SURVEYED. 



The part of the Colorado Desert investigated bj* this Bureau extends 

 from the international boundary line at the town of Calexico north- 

 ward 21 miles. The area includes T. 14 S., R. U E. , T. 15 S. , R. 14 E. , 

 T. 16S.,R. 14 E., T. 16S.,R. 15 E., T. 17S.,R. 14 E., and T. ITS., 

 R. 15 E. The area is entirety within San Diego Count}', Cal., and 

 lies about 115 miles east of the city of that name. Yuma, Ariz., is 

 about 60 miles to the eastward. 



Over the area mapped borings were made to a depth of at least (' 

 feet and were examined by the electrical method to determine the per- 

 centage of alkali salts. Note was made of conditions between the points 

 of sampling, and from these data the soil and alkali maps given on 

 pages 7 and 11 were constructed. Borings to a depth of 18 feet were 

 taken at a few places to determine the amount of alkali in the deeper 

 subsoil. In the field about 900 samples were examined. A number of 

 samples were sent to the laboratories for analysis and for the additional 

 information regarding the kind of alkali and for mechanical umily 



TOPOGRAPHY. 



The area mapped is a part of the delta of the Colorado River. The 

 surface in general is apparently level a smooth, gently sloping 

 plain, -admirably adapted for irrigation. The general fall is about 5 

 feet to the mile. Over the greater part of the area between Saiton 



