SALINE SOILS. 43 



COAST REGION. 



The littoral zone of tlic coast region comprises very little alkali oi- 

 saline land. A few areas of salt marsh occur along the shore, but not 

 much has been done toward their reclamation. 



The most extensive areas of salt soil in the coast region are those 

 found in the great valle3\s and plains. Certain of these areas have 

 existed for a long time. Others, inchiding some of the most serious, 

 have been developed luider irrigation within the last fifty years. The 

 most important tracts of salt land seen by the writers were near tiie 

 towns of Kelizane and Perregaux, in the Department of Oran. 



At Relizane the area covered b}' the irrigation systems amounts to 

 about 20,000 acres. As the water supply very frequently falls far 

 short of the amount necessary for the irrigation of this large area, part 

 of the land is ordinarily lying idle. The irrigation of surrounding 

 fields, together with seepage from the canals and laterals, has so raised 

 the water tat)Ie in this uncultivated land as to permit a constant upward 

 movement of the water ))y capillary force. The result has l)een that 

 salts which were formerly confined largely to the subsoil, or which 

 have been carried into tlie soil by subirrigation, have risen to the sur- 

 face and have accumulated there. The same process of accumulation of 

 salts in the upper layers of the soil has caused serious damage in many 

 parts of western North America. Around Relizane the old story has 

 been retold that land once fertile and producing luxuriant crops is 

 to-day bare of everything but a few stunted salt-loving weeds. Th(> 

 remains of irrigating laterals, fences, and houses alone show that the 

 land has ever been farmed. 



At Perregaux a simihir state of afi'airs prevails, but a nuu*h larger 

 area is affected. The salt land covers ati extensi\ e tract in the lower 

 part of the valley and includes fields that a few years ago were higiily 

 productive. A few attempts at reclamation have been made, and 

 some excellent fields were seen which were said to h;ive been l)adly 

 saline at one time; but no large areas have been impr()\ ed. 



The soil and other conditions of saline areas in the irrigated districts 

 of Algeria have no important peculiarities which distinguish them fioni 

 similar localities in Amei'ica. The salts are generally " white alkali."" 

 i. e., salts of sodium (other than the cai'bonate), magnesium, and lime. 

 . Chemical analyses of samples of these soils taken by the writers are 

 given on page 46. The predominant salts are of the "' white alkali "' 

 type, common salt (sodium chlorid) being tlie most abundant. Very 

 little ''black alkali"" (sodium carbonate) has been found in the coast 

 region of Algeria. 



The question of salt land in Algeria has been discussed in a recent 

 publication by Dugast. who devotes particular attention to the damage 

 that has been wrought in the vin»\vards of western Algeria by the rise 



