406 



Thirtieth Annual Report 



TABLE I. COMPOSITION OF 2-INCH SUCCESSIVE LAYERS IN A YARD SQUARE 

 HOLE ON ALKALINE LAND. SAMPLING TEST 



RECLAMATION OF ALKALI 

 An experiment in the reclamation of alkaline land on a tract 

 adjoining the Tempe Drainage Ditch adjacent to the Date Orchard 

 was cooperated in by the department. The experiment was planned 

 by Messrs. Goodin and Eder and nearly completed before our co- 

 operation was invited ; consequently, certain points were over- 

 looked, the original experiment having had in view the growing of 

 rice rather than the leaching of alkali. The soils were not sampled 

 before leaching began and sampling was delayed several days after 

 leaching closed, probably resulting in rapid rise of alkali from the 

 ground water as seemed to be indicated in a later experiment. An 

 estimate of the original condition of the tract can be based only 

 on the alkali left in high spots which received little leaching and 

 an adjacent unleached tract. Some years ago the land used for 

 the experiment was among the best in the Salt River Valley, but, 

 due to rising water table, had been abandoned to Bermuda grass, 

 which was finally killed out and gave place to saltbush. The Drain- 

 age Ditch has reduced the water table four to five and one-half feet 

 below the surface which is not sufficient for effective leaching and 

 permanent reclamation. The results, however, are highly inter- 

 esting and show among other things the completeness with which 

 white alkali may be leached and the tenacity with which black alkali 

 resists leaching. The higher white alkali shown by Nos. 7359, 

 7360, and 7361 as compared with Nos. 7383 and 7384 probably marks 

 the rapid rise of alkali in the interval after the first flooding and 



