348 Annual, Report Agriculturai, Experiment Station 



are slightly black alkaline and occasionally rise to within seven or 

 eight feet of the surface. The effect of gypsum on the rate of 

 percolation with this soil in 10-inch pots is given in Table XXII. 



table XXII. — percolation thru university farm soil aeter 



GYPSUM treatment 



Amount used 



None 



Half enough to neutralize Na2CQ3. . 

 Just enough to neutralize Na-COs.. 

 Twice amount to neutralize Na2C03 



1. Calculated from a 6-hour test by adding lOOOC.C. of water to each pot. 

 2. Insufficient head to keep up percolation for 5 hours. 3. Calculated from a 5- 

 hour test by adding 1000 C.C. of water to each pot. Note: The 10-inch pots used 

 in these tests each contained 10 kilos of soil. The soil used gave the following 

 analysis: Total water soluble salts dried at 110° C. .70 percent, chlorides as sodium 

 chloride .012 percent, black alkali as sodium carbonate .254 percent. 



An analysis of the percolates showed a saving in humus and 

 all plant foods with the exception of potassium. The saving in 

 nitrogen values at customary fertilizer prices would go far toward 

 paying for the gypsum treatment, even if it were possible to reach 

 the black alkali from the soil without the previous application of 

 gypsum. 



DATE PROCESSING AND MARKETING 



During the summer the appliances for ripening and processing 

 dates at the Tempe Date Orchard were inspected and put in order 

 for handling the fall crop. Several visits were made to the orchard 

 during the harvest to supervise the packing house operations and 

 give instructions in handling the different varieties under vary- 

 ing weather conditions. A suitable packing house for the Yuma 

 Orchard has been designed but not yet constructed. Before the 

 arrival of the Horticulturist the Chemist temporarily supervised 

 cultural operations at the date orchards. 



In the opinion of the writer after thirteen years of close study, 

 the date industry in Arizona, properly managed, can be recom- 

 mended to the investing public. Fresh dates of the soft varieties 

 which can be grown of such excellent quality in Arizona and mar- 

 keted as safely as any other crop are becoming known thruout the 

 country, and orders and inquiries from every part of the United 

 States are coming in quantities — a marked contrast to the condi- 

 tion ten years ago when the foreman of the orchard with diffi- 

 culty disposed of a few hundreds pounds at a nominal price by 



