Economic History Association The Arab Agricultural Revolution and Its Diffusion, 700-1100 Author(s): Andrew M. Watson Source: The Journal of Economic History, Vol. 34, No. 1, The Tasks of Economic History (Mar., 1974), pp. 8-35 Published by: Cambridge University Press on behalf of the Economic History Association Stable URL: http://www.jstor.org/stable/2116954 . Accessed: 26/10/2011 17:14 Your use of the JSTOR archive indicates your acceptance of the Terms & Conditions of Use, available at . http://www.jstor.org/page/info/about/policies/terms.jsp JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact [email protected]. Cambridge University Press and Economic History Association are collaborating with JSTOR to digitize, preserve and extend access to The Journal of Economic History. http://www.jstor.org The Arab AgriculturalRevolution and Its Diffusion,700-1100 THE rapidspread of Islam intothree continents in the seventh and eighthcenturies was followedby the diffusionof an equally remarkablebut less well documentedagricultural revolution. Orig- inatingmainly in India, where heat, moistureand available crops all favored its developmentand where it had been practiced for some centuriesbefore the rise of Islam, the new agriculturewas carriedby the Arabs or those theyconquered into lands which,be- cause they were colder and drier,were much less hospitableto it and where it could be introducedonly with difficulty.It appeared firstin the easternreaches of the early-Islamicworld-in parts of Persia, Mesopotamia and perhaps Arabia Felix-which had close contactswith India and where a few componentsof the revolution were alreadyin place in the centurybefore the rise of Islam. By the end of the eleventh centuryit had been transmittedacross the length and breadth of the Islamic world and had altered, often radically, the economies of many regions: Transoxania, Persia, Mesopotamia,the Levant, Egypt, the Maghrib, Spain, Sicily, the savannah lands on eitherside of the Sahara, parts of West Africa and the coastlands of East Africa.It had very far-reachingconse- quences, affectingnot only agriculturalproduction and incomesbut also populationlevels, urban growth,the distributionof the labor force, linked industries,cooking and diet, clothing, and other spheresof lifetoo numerousand too elusive to be investigatedhere. This paper will firstdescribe the main featuresof the Arab ag- riculturalrevolution and then tryto explainits diffusion. In the courseof my research,which has been carriedon over a numberof years and in manyplaces, I have benefitedfrom innumerable kindnesses, great and small, whichwill be acknowledgedelsewhere. Here I should like to thankthose to whom my debt is especiallylarge: ProfessorsClaude Cahen, Pedro MartinezMontavez, Roland Porteres,Vivi Tackholmand JohnWilliams, and Drs. David Dixon, Hans Helbaek, Jean-JacquesHemardinquer and CarmelloTrasselli. I am also gratefulto ProfessorsC. A. Ashleyand Karl Helleinerand Dr. Roger Owen for commenting on draftsof this article.As this articleis a preliminaryreport on my research,the verynumerous primary and secondarysources used have not been cited. The reader who is interestedin the primarysources will findsome guidance in the Appendix. In my forthcomingbook, New Crops in the Early-IslamicWorld: A Studyin Diffu- sion,most of the pointsmade in this articleare developedin greaterdetail and full referencesare given. S AgriculturalRevolution 9 I At thevery heart of therevolution were many new crops.Found by theArabs mainly in India,and in a fewcases in thelands of the conqueredSassanian Empire, which had receivedthem from India, the new cropswere introducedinto other, very different climatic regionswhere they played an importantpart in transformingcrop- pingpatterns. To mentiononly those plants whose progress we have been able to studyin detail-sixteenfood crops and one fibrecrop -the Arab conquestswere followedby the diffusionof rice,sor- ghum,hard wheat,sugar cane, cotton,watermelons, eggplants, spinach,artichokes, colocasia, sour oranges, lemons, limes, bananas, plantains,mangos and coconutpalms.1 With the exceptionof man- gos and coconutpalms, which could be grownonly in tropicalcli- matesand thereforeappeared only in ArabiaFelix and along the coast of East Africa,the diffusionwas verywide: the new crops came to be grownin nearlythe whole of the early-Islamicworld and not a fewbecame, for smaller or largerregions, of greateco- nomicimportance. Thislist of new cropsis alreadylong and impressive,but it is far fromcomplete. It does not includeother food and fibrecrops dif- fusedin the same period,whose advancehas proveddifficult to tracein the sources.Nor does it includeplants known in thesere- gionsbefore the Arab conquests, new strains of which appeared and were diffusedin Islamictimes. It excludesplants and treesused principallyas sourcesof fodder,spices, condiments,medicines, drugs,cosmetics, perfumes, dyes, nuts and wood,as well as garden flowersand ornamentalplants. In the disseminationof all these kindsof crops,too, the early centuries of Islam saw greatprogress. And finally,the listomits a wholehost of unwantedweeds which were inadvertentlydiffused along withthe otherplants, some of whichwere later to provevaluable but aboutwhose inglorious his- toryalmost nothing is known.In short,a completelist of evenonly the usefulplants would be long indeed,numbering well into the hundreds.The achievementwas remarkable.It seemsall the more so whenwe rememberthat the diffusion of theseplants over a very large area was compressedinto the firstfour centuries of Islam; thatmost of the plants,being native to tropicalregions, were not 1 Separatechapters will be devotedto the studyof the diffusionof each of these crops in pre-Islamicand Islamic times in my forthcomingbook mentionedin the precedingfootnote. 10 Watson easy to growin the coolerand drierregions into which they were taken;that the plantshad revolutionaryeffects on the wholeagri- culturalsystem; and thatthe workof introducingand spreading thesecrops was done by-or at least underthe rule of-a people notcommonly thought to have greenthumbs. There had been little thatwas comparablein earlierhistory. The achievementwas not to be equalleduntil modem times, when the discovery of new con- tinentsallowed the exchangeof plant life betweenparts of the worldwhich had previouslyhad littleor no contact. Hand in handwith the new cropscame changes in farmingprac- tices.For one thing,a numberof thenew cropsled to the opening of a virtuallynew agriculturalseason. In the lands of the Middle East and Mediterraneanthe traditional growing season had always been winter,the cropsbeing sown around the timeof the autumn rainsand harvestedin the spring;in the summerthe land almost alwayslay fallow,usually even in irrigatedregions where at least someof thecrops available to theancients could, with special care, have givensatisfactory yields. Those cropsmentioned as summer cropsin theclassical Roman manuals-barley, trimestre wheat, ses- ame and variouslegumes-played a minorrole in someparts of the northernMediterranean, where the summerwas relativelycool, thougheven there they seem to havebeen littleused and werenot integratedinto any systematicrotation. But in the southernand easternparts of the Mediterraneanthey were practicallynever grown,at leastnot as summercrops. There the summer season was to all intentsand purposesdead. Since,however, many of the new cropsoriginated in tropicalregions of India, SoutheastAsia, and CentralAfrica, they could be grownonly in conditionsof great heat.In particular,rice, cotton, sugar cane, eggplants, watermelons, hard wheat and sorghumwere all summercrops in the Islamic world,though rice and hardwheat could also be wintercrops in certainvery warm areas. Several other important new cropswhich we havenot been able to studyin detail,such as indigoand henna, were also grownin summer.Through the introductionof summer cropson a widescale, therefore, the rhythm of the agricultural year was radicallyaltered as land and laborwhich had previouslylain idle weremade productive. Morethan this, the openingof a summerseason was one of sev- eralfactors-perhaps the principal one-permitting systems of rota- tionwhich made muchmore intensive use of theland. Whereasin AgriculturalRevolution 11 Roman, Byzantine and Jewishagricultural traditions, the normal practicewas to crop the groundonly once everytwo years,and un- der veryexceptional circumstances once everyyear, there appeared all over the Islamic world rotationsin which the land was cropped fourtimes or more,instead of once, in a twenty-fourmonth period. Thus winterwheat could be followedby summersorghum. As one travelerobserved in Cyprus,where the practicehad no doubt been introducedduring the Arab occupation,a summercrop of cotton could be just fittedin between two crops of winterwheat grownin successiveyears. In partsof the Yemen wheat yielded two harvests a year on the same land, as did rice in Iraq. Where plants with a shortergrowing season were used, such as spinach, colocasia or eggplants,the land could be cropped three or more times a year. The variationswere endless. Naturally,multiple cropping mined the fertilityof the land and could not be borne by every type of soil. But to combat exhaustionand even to improvesome soils,