ALKALI CONDITIONS AT FOUGALA. 



83 



TABLE 16. Per cent of alkali in soil in old date plantation, station No. 3, Fougala, 



Algeria. 1 



1 Mr. Seidell's original analyses of the samples from this station are as follows: 



The results of long-continued irrigation with pure water and of good drainage 

 through the holes in the hard pan are clearly shown in the very much lower percent- 

 ages of alkali than at stations 1 and 2. The most remarkable feature of this soil is the 

 almost complete absence of common salt, so abundant at the other two stations at 

 Fougala, where indeed it constituted the bulk of the alkali. The analyses of the 

 soils from these three stations represent three stages in the reclamation of very 

 alkaline desert land and are very instructive. The conditions somewhat resemble 

 those in the Salton Basin, California, where the irrigation water is also very pure 

 and where likewise the alkali is largely composed of chlorides. In the latter region, 

 however, there is no hard pan through which holes for drainage can be dug and which 

 would serve to keep the alkali down when once it was washed out of the soil. Where 

 good drainage can be provided the soils in the Salton Basin doubtless can be as 

 completely freed from harmful excess of alkali as those of Fougala have been. 



Station No. 4 at Fougala was situated in a very alkaline spot too alkaline to grow 

 any crops near a date palm which was yellow and stunted, but which had never- 

 theless managed to live twenty years or more. Only the surface crust was secured; 

 it showed the following percentages of alkali salts soluble in an excess (20 times the 

 weight of the soil sample) of water. The surface crust from station No. 1 is also 

 given, analyzed in the same way. 



