The Yuma Mesa 263 



decay of crops grown that the surface 18 inches to 2 feet now 

 appears to be, and is often called, a heavy adobe soil. Alfalfa 

 planted as a cover crop in this old orchard has done very well in- 

 deed, as is shown by one of the pictures accompanying this report. 

 Likewise cow peas have made an excellent growth. Sesbania, a 

 rank growing legume, has been used on the Mesa for green man- 

 uring purposes and it promises to be very satisfactory. 



SUMMARY 



The climate of the Yuma Mesa combines the smallest rainfall, 

 the lowest relative humidity, and the greatest percentage of sun- 

 shine of any citrus region in North America. This combination 

 and its freedom from injurious frost make the Mesa a most prom- 

 ising region for citrus culture. 



The fruit grown on the Yuma Mesa is unexcelled in color, 

 quality, early maturity and freedom from blemishes. 



The Mesa is now and probably can be kept free from injurious 

 citrus pests. 



The Mesa is particularly well adapted to growing such other 

 crops as dates, olives, grapes, figs and early truck. 



The Yuma Mesa, joining the main line of the Southern Pacific 

 at Yuma, is insured efficient shipping facilities. 



While ordinary field crops probably cannot compete with simi- 

 lar crops grown in the valley, they can be produced in quantities 

 sufficient for home needs. 



The total plant food in the soil of the Mesa is relatively low, 

 but its availability is high. Chemical analyses show it to compare 

 favorably with soils from the citrus districts of California and 

 Florida. 



The irrigating waters of the Colorado River will in large part 

 supply the fertilizing elements which prove so expensive in many 

 citrus sections. 



Cover crops which have been found desirable in the handling 

 of all orchards can be grown successfully on the Mesa. 



In view of the findings set forth in this report this commission 

 hereby recommends that the Yuma Mesa be brought under irriga- 

 tion according to the plans proposed by the engineers of the Recla- 

 mation Service, and developed by the growing of citrus and other 

 sub-tropical fruits. 



