Too much stress, however, cannot be laid upon these figures, since the fertility of a soil is very greatly influenced by texture and physical constitution, perhaps more so by these factors than by chemical composition.
The paring and burning of land, although formerly practised as an ordinary means of improving the texture and fertility of arable fields, can now only be looked upon as a practice p to be adopted for the purpose of bringing rapidly into cultivation very foul leys or, land covered with a coarse turf.
- The cultivation of sugar was first introduced in the middle of the 17th century, and owing to the cheapness of labour, the extreme fertility of the soil and the care bestowed on its cultivation, became the staple product of the island.
Palgrave says little of the desert part of the journey or of its Bedouin inhabitants, but much of the fertility of the oases and of the civility of the townsmen; and like other travellers in Nejd he speaks with enthusiasm of its bright, exhilarating climate.
North of Katif it is desert and only inhabited by nomads; at Katif, however, and throughout the district to the south bordering on the Gulf of Bahrein there are ample supplies of underground water, welling up in abundant springs often at a high temperature, and bringing fertility to an extensive district of which El Hofuf, a town of 15,000 to 20,000 inhabitants, is the most important centre.