20 AGRICULTURE IN THE SAHARA DESERT. 



As we have seen, the bottoms of the basins where the palms are 

 grown are not only far below the summits of the surrounding sand 

 hills, the height of which is increased by the sand removed in exca- 

 vating the Gardens, but are even considerablv lower than the mean 

 surface of the country. It is said that in starting a new garden the 

 practice is first to sink a well in the bottom of the basin in order 

 to find out the depth at which water stands. The floor of the basin 

 is then scooped out until it is so near ground water that when a hole 

 1^ to 4 feet deep is made to receive the young palm its roots will 

 have to descend only about 1 or 1^ feet to reach standing water. It 

 is said that to attain the desired depth it is generally necessary to 

 remove 10 to 20 feet of sand. 



The date palm is always artificially planted in the Oued Souf, 

 never springing up spontaneously from seed, as in other oases. It 

 is never planted elsewhere than on the floor of the basins among the 

 dunes, or at most a very few feet above the bottom. These basins 

 are probably in all cases natural depressions, but are artificially 

 deepened to facilitate the roots reaching ground water. New gar- 

 dens are frequently started in unoccupied basins, and old ones belong- 

 ing to enterprising owners are being constantly extended b}^ cutting 

 down the slopes of the bordering sand hills and planting a few palms 

 every year or so. (See PL III, fig. 2.) The larger and better-situ- 

 ated basins are now all occupied by gardens, and for the newest 

 plantations it is often necessary to use small, shallow depressions, 

 where there is frequently room for but half a dozen trees. Some- 

 times the slope is not cut down quite to the level of the older part of 

 the garden, the new pahns being set out slightly above the level, on a 

 terrace made in the side of the sand hills. (PI. IV, fig. 1.) "\\lien 

 planted on the slope or near the foot of it, sections of palm log or a 

 number of palm leaves are placed on the uphill edge of the hole to 

 check the drifting of sand into it. 



Owing to the scarcity of offshoots in the Souf region, the work of 

 extending the gardens does not proceed as rapidly as the energetic 

 population could wish. The French attribute the nonproduction of 

 offshoots in the Souf to the fact that the palms are so valuable there 

 that it does not pay to let the offshoots develop, absorbing a part 

 of the energy that would otherwise go to fruit production. They 

 believe that the Souafas find it actually cheaper to send to the Oued 

 Rirh for suckers, paying 40 to GO cents apiece for them in addition 

 to the cost of transportation, than to let them grow on their own trees. 

 Economic considerations aside, however, it is probable that the date 

 palm does not sucker as freely in the Oued Souf as in other oases, 

 because of the dry condition of the surface soil, never wet Ijy irriga- 

 tion, and because the blowing sand tends to bury the young ofl'shoots 

 and to lacerate their tender buds. The natives, when questioned 



