History usually conveys the notion that the agricultural revolution took place in recent times in the form of rotation of crops, advanced irrigation techniques, plant improvements, etc., and that some of those changes took place only in the last couple of centuries in Europe, whilst others are occurring today. It is explained that such revolutionary changes fed the increasing world population, released vast numbers of workers from the land and allowed agriculture to produce a capital surplus, which was invested in industry, thus leading to the industrial revolution of the 18th-19th century.
This is the accepted wisdom, until one comes across works on Muslim agriculture and discovers that several of those changes took place over ten centuries ago in the Muslim world, some of them being the foundations of important modern innovations. Watson, Glick and Bolens, in particular, show that major breakthroughs were achieved by Muslim farmers on the land, and by Muslim scholars with their treatises on the subject. Thus, as with other subjects, prejudice distorts history, and the achievements in the world of Islam ten centuries ago are covered up. This point is raised by Cherbonneau as long as the 1940s when he wrote: “It is admitted with difficulty that a nation in majority of nomads could have had known any form of agricultural techniques other than sowing wheat and barley. The misconceptions come from the rarity of works on the subject… If we took the bother to open up and consult the old manuscripts, so many views will be changed, so many prejudices will be destroyed.”
The Islamic Agricultural Revolution
As early as the 9th century, an innovative agricultural system became central to economic life and the organization of production in the Muslim land. The great Islamic cities of the Near East, North Africa and Spain, Artz explains, were supported by an elaborate agricultural system that included extensive irrigation and an expert knowledge benefiting from some of the most advanced agricultural methods known so far. The Muslims reared the finest horses and sheep and cultivated the best orchards and vegetable gardens. They knew how to fight insect pests, how to use fertilizers, and they were experts at grafting trees and crossing plants to produce new varieties. Glick defines the Muslim agricultural revolution in the introduction of new crops, which, combined with extension and intensification of irrigation, created a complex and varied agricultural system, whereby a greater variety of soil types were put to efficient use. In this system, fields that had been yielding one crop annually at most were capable of yielding three or more crops, in rotation. As a result of such intensive agriculture, agricultural production responded to the demands of an increasingly sophisticated and cosmopolitan urban population by providing the towns with a variety of products unknown elsewhere, for example, in Northern Europe.  Scott, on his part, considered that the agricultural system of the Spanish Muslims, in particular, was “the most complex, the most scientific, the most perfect, ever devised by the ingenuity of man.” 
Such advancement of Muslim farming, according to Bolens, was owed to the adaptation of agrarian techniques to local needs, and to “a spectacular cultural union of scientific knowledge from the past and the present, from the Near East, the Maghreb, and Andalusia. A culmination subtler than a simple accumulation of techniques, it has been an enduring ecological success, proven by the course of human history.”  A variety of fertilizers were used according to a well-advanced methodology; whilst a maximum amount of moisture in the soil was preserved.  Soil rehabilitation was constantly cared for, and preserving the deep beds of cropped land from erosion was, as Bolens explains, “the golden rule of ecology”, and was “subject to laws of scrupulous careful ecology. “ 
The success of Islamic farming also lay in hard work. No natural obstacle was sufficiently formidable to check the enterprise and industry of the Muslim farmer. He tunneled through the mountains, his aqueducts went through deep ravines, and he leveled with infinite patience and labor he leveled the rocky slopes of the sierra in Spain. Watson sums up by arguing that the rise of productivity of agricultural land and sometimes of agricultural labor was due to the introduction of higher yielding new crops and better varieties of old crops, through more specialized land use which often centered on the new crops, through more intensive rotations which the new crops allowed, through the concomitant extension and improvement of irrigation, through the spread of cultivation into new or abandoned areas, and through the development of more labor intensive techniques of farming. These changes, themselves, were positively affected by changes in other sectors of the economy: growth of trade, enlargement of the money economy, increasing specialization of factors of production in all sectors, and with the growth of population and its increasing urbanization. 
From Andalusia to the Far East, from the Sudan to Afghanistan, irrigation remained central, and the basis of all agriculture and the source of all life.  The ancient systems of irrigation the Muslims inherited were in an advanced state of decay.  The Muslims repaired them and constructed new ones; besides devising new techniques to catch, channel, store and lift the water, and making ingeniously combine available devices.  All of the books of Filaha (agriculture), whether Maghribi, Andalusian, Egyptian, Iraqi, Persian or Yemenite, Bolens points out, insist meticulously on the deployment of equipment and on the control of water. 
Agricultural Machines and Construction
Water that was captured through a variety of ways was then successively channeled, stored and lifted using the different techniques and varied devices for each operation. Irrigation became cheap, affecting lands previously impossible or uneconomic to irrigate.  Irrigated fields yielded as many as four harvests annually,  which, as in Spain, laid the foundations for the country’s prosperity.  Damming of rivers to provide households and mills with power, and for irrigation, was also widespread.  The introduction of the nuria (a water lifting device) in any district has always had revolutionary consequences upon agricultural productivity. Being relatively inexpensive to build and simple to maintain, the nuria enabled the development of entire huertas that were intensively irrigated. 
In Cordoba, Al-Shaqundi (13th century) speaks of 5000 nurias (possibly including both lifting and milling devices) on the Guadalquivir.  Some are still in use, as at La Nora, six km from the Murcia city Centre, where although the original wheel has been replaced by a steel one, the ancient system is otherwise virtually unchanged.  In general, these Islamic irrigation techniques that were transferred to Spain were adapted to specific natural conditions.  The Muslims, Forbes holds, should be credited with important developments of irrigation in the Western Mediterranean. They did not just extend the irrigated area in Spain and Sicily, but also knew how to drain rivers and how to irrigate their fields by systems of branch channels with an efficient distribution of the available water.  They also captured rainwater in trenches on the sides of hills or as it ran down mountain gorges or into valleys; surface water was taken from springs, brooks, rivers and oases, whilst underground water was tapped by creating new springs, or digging wells. 
Notes and References
 See A. M. Watson: Agricultural Innovation in the Early Islamic World, Cambridge University Press, 1983; A. M. Watson, “The Arab Agricultural Revolution and its Diffusion”, in The Journal of Economic History 34 (1974), pp. 8-35; Thomas Glick, Islamic and Christian Spain in the Early Middle Ages, Princeton University Press, 1979; T. Glick, Irrigation and Hydraulic Technology: Medieval Spain and its Legacy, Varorium, Aldershot, 1996; L. Bolens, Les méthodes culturales au Moyen Age d’après les traités d’agronomie andalous: Traditions et techniques, Geneva, 1974; L. Bolens, Agronomes Andalous du Moyen Age, Geneva/Paris, 1981 and L. Bolens, “L’Eau et l’irrigation d’après les traités d’agronomie Andalous au Moyen Age (XI-XIIèmes siècles)”, Options Méditerranéenes, vol. 16, December 1972, pp. 65-77.
 A. Cherbonneau: “Kitab al-Filaha of Abu Khayr al-Ichbili”, in Bulletin d‘Etudes Arabes (Alger), vol. 6, 1946, pp. 130-44; p. 130. See also Abu al-Khayr al-Ishbili, Kitâb al-Filâh’a ou Le Livre de la culture [by Aboû ‘l-Khayr ach-Chadjdjâr al-Ichbîlî], notice et extraits traduits par Auguste Cherbonneau, éclaicissements par Henri Pérès, Alger: Carbonel, 1946.
 Frederick B. Artz, The Mind of the Middle Ages, The University of Chicago Press, 1980, 3rd edition revised, p. 150.
 T. Glick, Islamic and Christian Spain in the Early Middle Ages, p. 78.
 S. P. Scott, History of the Moorish Empire in Europe, J.B. Lippincott Company, London, 1904, vol. 3, p. 598.
 L. Bolens, “Agriculture”, in Encyclopedia of the History of Science, Technology and Medicine in Non Western Cultures, edited by Helaine Selin, Kluwer Academic Publishers, Dordrecht/Boston/London, 1997, pp. 20-2.
 T. Glick, Islamic and Christian Spain in the Early Middle Ages, p. 75.
 L. Bolens, “Agriculture”, op. cit., p. 22.
 S.P. Scott, History, op. cit., p.604.
 A. Watson, Agricultural Innovation, op. cit., pp. 2-3.
 L. Bolens, “Irrigation”, in Encyclopedia of the History of Science, Technology and Medicine in Non Western Cultures, op. cit., pp. 450-2; p. 451.
 A. M. Watson, Agricultural Innovation, op. cit., p. 104.
 Ibid, pp. 109-10.
 L. Bolens, “Irrigation”, op. cit., p. 451.
 A. M. Watson, Agricultural Innovation, op. cit., p. 104.
 T. Glick, Islamic and Christian Spain, op. cit., p. 75.
 D. R. Hill, Islamic Science and Engineering, Edinburgh University Press, 1993, p. 161.
 Ibid, pp. 159-69.
 T. Glick, Islamic and Christian Spain, op. cit., p. 74.
 Al-Saqundi, “Elogio del Islam espanol”, p. 105; quoted in T. Glick, Islamic and Christian Spain, op. cit., p.75.
 D. R. Hill, Islamic Science and Engineering, op. cit., p. 97.
 E. Lévi Provençal, Histoire de l‘Espagne Musulmane, Maisonneuve, Paris, 1953, 3 vols.; vol. 3, p. 279.
 R. J. Forbes, Studies in Ancient Technology, Leiden, E. J. Brill, 1965, 2nd revised edition, vol. 2, p. 49.
 A. M. Watson, Agricultural Innovation, op. cit. p. 107.
Source: Taken with modifications from Muslimheritage.com