22 THE DATE PALM. 



The samples were all taken from one pit : the first three 

 samples from one side of it and the remaining six samples from 

 the other. The depths at which they were taken are shown in 

 the above diagrams of the two soil sections. The ground was 

 white with salt when the samples were taken. Twenty-one date 

 off-shoots were planted in this land in 1910 and 230 in 1912, 

 making 251 in all. There are now only 60 plants alive, i.e., the 

 death-rate was approximately 76 per cent, instead of the 20 30 per 

 cent, or less usually got with fair treatment on ordinary lands. On 

 our periodic inspections the plants in the Memorial Hall garden 

 always appeared to be well-watered, and as far as could be seen 

 the heavy mortality among these trees was due to the salts in the 

 soil. The plants which are still alive in this plantation are now 

 growing vigorously. Some of them bore fruits last season (1915) 

 and several more are in flower this year. 



In arid districts, when dates are planted on lands containing 

 much alkali and the trees obtain their water from a high subsoil 

 water table and no irrigations are given to land between the 

 trees, either to crops or for other reasons, a white crust of salt 

 very soon forms on the surface of the soil. This is due to the fact 

 that water is constantly depositing its load of salt as it is being 

 evaporated from the surface of the land, and as the evaporating 

 current in such a case is always upwards, the salt deposit 

 at the soil surface continues to be added to. In this way a very 

 large crust of salt may accumulate on the surface of the soil of 

 a date plantation, even when the soil below the surface contains 

 very little salt. Where ordinary crops can be grown between 

 the trees and these are irrigated occasionally, the surface deposit 

 of salt is dissolved by the water, carried down into the subsoil 

 and redistributed to some extent at each irrigation. A thick 

 surface crust of salt, therefore, does not form in such cases unless 

 the land contains a large amount of alkali. A surface deposit of 

 salt similar to that described above collects on the bare land 

 between the date-palms in arid undrained places where the land 

 is not flooded, but the trees are planted in small channels or small 

 circular basins and receive their water directly from these. In 



