The Aljarafe district to the west of Seville was where the agronomists Abū’l-Khayr and Ibn Hajjāj conducted agricultural experiments and observations in the 11th century, as did Ibn al-‘Awwām towards the end of the 12th century:

“This last city [Seville] is large and well-populated. Its walls are strong, its markets numerous, and it is a centre of great commerce. Its people are wealthy. The main trade of this city is in [olive] oils which are exported to the east and the west by land and sea. These oils come from a district called al-Sharaf [Aljarafe] which extends for 40 milles and which is entirely planted with olives and figs. It reaches from Seville as far as Niébla, having a width of more than 12 milles. It comprises, it is said, eight thousand thriving villages, with a great number of baths and fine houses. From Seville to the place where this district begins is 3 milles. It is named al-Sharaf (in Arabic, ‘the height’, or ‘the elevation’) because, in effect, the land rises on leaving Seville, forming a hill of a reddish colour running from south to north. The groves of olive trees stretch as far as the bridge at Niébla. Seville is built on the banks of a great river, that is to say, the river of Cordoba.” (Translated from Description de l'Afrique et de l'Espagne par Edrisi, texte arabe, publié avec une traduction, des notes et un glossaire par R. Dozy et M. J. de Goeje. Leiden: E. J. Brill, 1866, p. 215)

“The best-known olive-growing region in al-Andalus was the area to the west of Seville called al-Sharaf – Aljarafe – “situtated upon a high plateau of red earth, of an area approximating forty miles square, which can be traversed walking always in the shade of olive and fig trees.” Aljarafe oil was highly esteemed and was exported to the east (to Alexandria, according to al-Shaqundî). At the time of the conquest of Seville (1248), Julio González calculates the number of olive trees in the province at more than two and a half million, producing five million kilos of olives. By the end of the century, however, tithes on wheat were more lucrative than the olive tithe, although both were considerable. The distribution of land use of the Aljarafe today (30 percent in olives, 23 percent in wheat, 35 percent in forest, and 12 percent divided among other crops) is probably close in profile to what it was at the end of the thirteenth century, no doubt representing some shift in emphasis toward wheat-growing after the Christian conquest. Other olive-bearing areas of the peninsula may not have matched the Aljarafe in density, but were well known for olive cultivation: Idrisî referred to the Lérida-Mequinenza region as the Iqlîm al-zaitûn - region of the olives.” (Glick, T.F. Islamic and Christian Spain in the Early Middle Ages. New-Jersey: Princeton University Press, 1978, p. 79)